HELENA VALLEY,
MONTANA,
AREA
ENVIRONMENTAL
POLLUTION STUDY
U.S. ENVIRONMENTAL PROTECTION AGENCY
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HELENA VALLEY, MONTANA,
AREA ENVIRONMENTAL
POLLUTION STUDY
ENVIRONMENTAL PROTECTION AGENCY
Office of Air Programs
Research Triangle Park, North Carolina
January 1972
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The AP series of reports is issued by the Environmental Protection Agency to
report the results of scientific and engineering studies, and information of
general interest in the field of air pollution. Information presented in this
series includes coverage of intramural activities involving air pollution research
and control technology and of cooperative programs and studies conducted in
conjunction with state and local agencies, research institutes, and industrial
organizations. Copies of AP reports are available free of charge — as supplies
permit — from the Office of Technical Information and Publications, Office of
Air Programs, Environmental Protection Agency, Research Triangle Park,
North Carolina 27711
Office of Air Programs-Publication No. AP- 91
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PREFACE
The Helena Valley, Montana, Area Environmental Study was conducted
cooperatively, from June 1969 through June 1970, by the Federal Govern-
ment and the State of Montana.
Because it had been alleged that pollutants are contributing to the
endangerment of health and welfare in the Helena Valley, this study was
undertaken to provide factual information bearing on the allegations and to
aid in delineating the solution of any observed problem.
The investigation concerned contamination of the environment by arsenic,
cadmium, lead, zinc, and sulfur dioxide from the industrial smelting complex
in the city of East Helena.
Since the atmosphere was suspected as being the major pollutant-transport
mechanism in the area's environment, the National Air Pollution Control
Administration* was designated to lead and coordinate Federal participation
in the study.
The study included the investigation of in-plant air quality and lead
accumulation in smelter workers. However, since right-of-entry to the plants
was gained under Montana State law, which prohibits publication or public
release of any information gathered during in-plant surveys, such material is
not included in this report. Results were furnished to the Montana State
Department of Health for such use as it may deem appropriate.
*Presently the Office of Air Programs of the Environmental Protection Agency.
in
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ACKNOWLEDGMENTS
Mr. Benjamin F Wake, Director, Division of Air Pollution, State Depart-
ment of Health, and Mr. Earl V. Porter, Director, Region VIII, Office of Air
Programs, Environmental Protection Agency, served as the respective State and
Federal Co-Directors of the study.
Mr. Norman A. Huey, Assistant Director, Region VIII, Office of Air
Programs, Environmental Protection Agency, was principal technical coordi-
nator and compiler of the study.
Mr. William H. Megonnell, Compliance Officer, Office of Air Programs,
Environmental Protection Agency, assisted with the overall study direction
and report preparation.
IV
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LIST OF FIGURES
Figure Page
2-1 Sulfur Dioxide Monitoring Locations 26
2-2 S02 Frequency Distribution at Sampling Location 1 29
2-3 S02 Frequency Distribution at Sampling Location 2 30
2-4 S02 Frequency Distribution at Sampling Location 3 31
2-5 S02 Frequency Distribution at Sampling Location 4 32
2-6 S02 Frequency Distribution at Sampling Location 5 33
2-7 Annual Average Spatial Distribution of S02, June 1969
through May 1970 34
2-8 Study Period Spatial Distribution of S02 , July through
October 1969 35
2-9 Spatial Distribution of S02 During Partial Plant Shutdown,
June 1969 36
2-10 Spatial Distribution of SO2 , July 1969 37
2-11 Spatial Distribution of SO2 , August 1969 38
2-12 Spatial Distribution of S02 , September 1969 39
2-13 Spatial Distribution of S02, October 1969 40
2-14 Spatial Distribution of S02, November 1969(1 Month After
End of Study Period) 41
2-15 Winter Spatial Distribution of S02 , December 1969 through
February 1970 42
2-16 Spatial Distribution of S02 , March through May 1970 43
2-17 Sulfur Dioxide Trend from July 1968 to November 1969 45
2-18 Settleable Particulate Arsenic Radial Distribution 52
2-19 Settleable Particulate Cadmium Radial Distribution 54
2-20 Settleable Particulate Lead Radial Distribution . . . 56
2-21 Settleable Particulate Zinc Radial Distribution 59
4-1 Sampling Locations 67
5-1 Control and Exposed Plant Sites at Station 1 82
5-2 Locations of Greenhouses and Experimental Gardens in the East
Helena Study 83
5-3 Average Heavy-Metal Levels in Plants Grown in Experimental
Gardens Around East Helena in 1969 86
5-4 Heavy-Metal Content of Soils in Experimental Gardens Around
East Helena in 1969 87
5-5 Sulfur Dioxide Leaf Injury to Alfalfa at Station 3 93
6-1 Animal Collection Sites 96
6-2 Plant Collection Sites 102
10-1 Simplified Flow Diagram for Lead Plant 148
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10-2 Simplified Flow Diagram for Slag-Processing Plant 155
10-3 Simplified Flow Diagram for Pigment Plant 159
11-1 Annual Wind Rose, Helena, Montana 162
11 -2 Temperature Soundings on Day with Clear Skies and Light Winds. . 164
11-3 Typical High-Level Temperature Soundings, Summer and Winter . 165
11 -4 Graphical Determination of Afternoon (Maximum) Mixing Depth.. 168
11-5 Estimated Mean Concentrations of SO2 (ppm) from Three
Sources in Helena Valley, June through October 1969 173
11 -6 Estimated Mean Annual Concentrations of S02 (ppm) from
Three Sources in Helena Valley. (No Fan or Heater on Stack) .... 175
11-7 Estimated Mean Annual Concentrations of S02 (ppm) from
Three Sources in Helena Valley 176
11-8 Estimated Mean Annual Concentrations of S02 (ppm) from
ASARCO Stack with Fan and Heater 177
VI
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LIST OF TABLES
Table Page
1-1 Estimated Population of Helena and East Helena 6
1 -2 Helena Valley Property Evaluation 8
1-3 Heavy-Metal Levels in Hair for Three Cities 19
2-1 Number of Occurrences and Length of Time Specific
Levels Exceeded 27
2-2 Comparison of Sulfation Predictions with Measured ppm Values . . 44
2-3 Particulate Sulfate Summary Statistics 46
24 Particulate Acidity Summary Statistics 47
2-5 Total Suspended Particulate Summary Statistics 48
2-6 Settleable Particulate Results 49
2-7 Soiling Index Summary Statistics, June Through October 1969 . . 49
2-8 Particulate Arsenic Summary 50
2-9 Particulate Cadmium Summary 53
2-10 Particulate Lead Summary 55
2-11 Particulate Zinc Summary 58
3-1 Water Quality Analytical Results 63
4-1 Instrumental Parameters for Determining Lead and Zinc Content
of Soil 69
4-2 Estimates of Experimental Error 70
4-3 Estimated Relative Importances of Errors in Sampling and
Laboratory Analysis 71
4-4 Soil Metal Content as Function of Distance from Smelter 72
4-5 Expected Lead, Zinc, Cadmium, and Arsenic Contents of
Cultivated Soils Along Traverses A, B, and C 73
4-6 Expected Lead, Zinc, Cadmium, and Arsenic Contents of
Uncultivated Soils Along Traverse D 74
5-1 Heavy-Metal Content of Vermiculite and Soils Used in
Greenhouses and Experimental Gardens 84
5-2 Average Heavy-Metal Content of Experimental Vegetation 85
5-3 Ranges of Heavy Metals in Plants Sampled from Residential
Gardens and Ranches in East Helena Area 89
5-4 Ranges of Heavy Metals in Garden Plants, Small Grains, Alfalfa,
and Pasture Grasses Sampled in East Helena Area in 1969 90
5-5 Injury Found on Indigenous Vegetation 91
5-6 Type and Extent of Leaf Damage on Experimental Vegetation .... 92
5-7 Growth Suppression of Experimental Vegetation 93
6-1 Lead and Cadmium in Animal Tissues 97
6-2 Accounts of Species Taken in East Helena Area, Summer 1969 ... 99
Vll
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6-3 Lead and Cadmium Concentrations of Soil, Grass,
and Rodent Tissues 101
6-4 Lead and Cadmium Content of Soil and Lettuce 103
6-5 Comparison of Washed with Unwashed Lettuce from the
Same or Neighboring Gardens 104
6-6 Heavy-Metal Content of Lettuce Grown in East Helena and in
East Helena Soil Transported to Missoula 104
6-7 Lead and Cadmium Contents of Rabbit Tissues 106
6-8 Lead and Total Sulfur in Conifer Foliage in East Helena, 1969 ... 108
7-1 Collection Sites for Horse-Mane Samples 115
7-2 Analyses for Arsenic, Zinc, Cadmium, and Lead in
Horse-Mane Hair 116
7-3 Ranking of Sites by Average Metal Content of Horse Mane 119
7-4 Field Notes on Horses Sampled 120
7-5 Postmortem Organ Analyses of Horse, Site 2 122
7-6 Selected Metal Contents of Miscellaneous Animal Products 124
8-1 Distribution of Arithmetic Mean Hair Lead Levels by City 126
8-2 Distribution of Arithmetic Mean Hair Cadmium Levels by City .. 127
8-3 Distribution of Arithmetic Mean Hair Arsenic Levels by City 127
8-4 Distribution of Arithmetic Mean Hair Zinc Levels by City 128
8-5 Distribution of Arithmetic Mean Hair Copper Levels by City 128
8-6 Distribution of Hair Lead Levels by City 129
8-7 Distribution of Hair Cadmium Levels by City 129
8-8 Distribution of Hair Arsenic Levels by City 130
8-9 Distribution of Hair Zinc Levels by City 130
8-10 Distribution of Hair Copper Levels by City 131
8-11 Summary of Arithmetic Mean Concentrations of Trace Metals in
East Helena, Helena, and Bozeman, Montana 131
8-12 F Ratios of Trace-Metal Concentrations in East Helena, Helena,
and Bozeman, Montana 132
9-1 Estimated Zinc Balance in Man 135
9-2 Estimated Cadmium Balance in Man 136
9-3 Estimated Arsenic Balance in Man 137
9-4 Estimated Lead Balance in Man 138
9-5 Estimated Daily Consumption of Garden Vegetables and Fruits .. 139
9-6 Estimated Total Daily Intake of Arsenic, Cadmium, Lead, and
Zinc from Diet, Water, and Air 140
9-7 Estimated Daily Intake of Arsenic, Cadmium, Lead, and Zinc
from the Diet 141
10-1 1968 Emissions in Helena Valley, Montana, Area 145
10-2 Emissions from East Helena Industrial Complex 147
11-1 Monthly Mean Windspeeds, Helena, Montana, 1937 to 1963 163
11 -2 Seasonal and Annual Inversion Frequency at Helena, Montana . . 166
11-3 Seasonal and Annual Inversion Frequency at Idaho Falls, Idaho 166
11-4 Stability in Helena Valley jg7
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11-5 Normal and Actual Monthly Windspeed. Precipitation Amounts,
and Number of Days with Precipitation, Helena, Montana 169
11-6 Three Most Significant Sulfur Dioxide Sources 169
11-7 Short-Term Concentrations of S02 at East Helena Park 170
11-8 Estimated Maximum Ground-Level Centerline Concentrations of
SO2 and Distance from Source for Selected Meteorological
Conditions 171
11-9 Concentrations of S02 at East Helena Park During Aerodynamic
Downwash from Source Buildings, Windspeed of 8 mph 172
IX
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CONTENTS
1. SUMMARY 1
RESULTS AND RECOMMENDATIONS 1
INTRODUCTION .. .." 2
Background Information 4
Review of Previous Pollution Studies 7
ENVIRONMENTAL EVALUATION 9
Sulfur Dioxide 9
Arsenic 11
Cadmium 12
Lead 13
Zinc 14
EVALUATION OF POLLUTANT EFFECTS 15
Vegetation 15
Animals 17
Humans 18
POLLUTANT SOURCES 19
Sulfur Dioxide Emissions 20
Particulate Emissions 22
Waste Water Emissions 23
Solid Waste Disposal 23
2. SURVEY OF AIRBORNE POLLUTANTS 25
INTRODUCTION 25
SULFUR DIOXIDE 25
Point Measurements of Sulfur Dioxide 25
Spatial Distribution of Sulfur Dioxide 28
Long-Term Trends 44
Sulfur Dioxide Related Measurements 44
NONSPECIFIC PARTICULATES 47
Total Suspended Particulates 47
Settleable Particulates 47
Windblown Particulates 49
Soiling Index 49
METALLIC PARTICULATES 50
Arsenic 50
Cadmium 53
Lead 55
Zinc 57
OZONE AND NITROGEN DIOXIDE '.. 58
Ozone 58
Nitrogen Dioxide 60
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REFERENCES FOR CHAPTER 2 60
3. SURVEY OF WATER QUALITY 61
INTRODUCTION 61
TYPES OF WATER SUPPLIES 61
SAMPLING 61
LABORATORY METHODS 62
RESULTS 62
DISCUSSION OF RESULTS 62
SUMMARY 63
4. ABUNDANCE AND DISTRIBUTION OF LEAD, ZINC,
CADMIUM, AND ARSENIC IN SOILS 65
INTRODUCTION 65
CHARACTER OF SOILS 65
SAMPLING 65
LABORATORY METHODS 68
Evaluation of Errors Due to Sampling and Laboratory Analysis.. 70
DISCUSSION OF RESULTS 71
Lead 74
Zinc 75
Cadmium 76
Arsenic 77
Other Elements 77
SUMMARY AND CONCLUSIONS 78
REFERENCES FOR CHAPTER 4 80
5. SOIL AND VEGETATION STUDY 81
INTRODUCTION 81
ORIGIN OF HEAVY METALS IN VEGETATION 81
Methods and Materials 81
Results and Discussion 84
SUMMARY 88
AMOUNT OF HEAVY METALS IN SOILS AND VEGETATION .. 88
Methods and Materials 88
Results and Discussion of Soil Analyses 88
Results and Discussion of Vegetation Analyses 89
SUMMARY 90
VISIBLE PLANT DAMAGE TO INDIGENOUS AND
GREENHOUSE VEGETATION 90
Methods and Materials 90
Results and Discussion 91
SUMMARY '.'.'.'.".'.'.'.'.'.".'..'. 94
6. EFFECTS OF AIR POLLUTION ON INDIGENOUS ANIMALS
AND VEGETATION 95
INTRODUCTION ' ' ' ' 95
ACCUMULATION OF LEAD AND CADMIUM IN
INDIGENOUS ANIMALS 95
LEAD AND CADMIUM IN GARDEN VEGETABLES .'. . . . . 102
xii
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Source of Lead and Cadmium in Garden Vegetables 104
UPTAKE OF CADMIUM AND LEAD FROM FOOD SOURCES ... 104
CONIFER FOLIAGE INVESTIGATIONS 107
Sulfur and Lead Content 107
Histological Examinations 109
BIBLIOGRAPHY FOR CHAPTER 6 110
7. EFFECTS OF AIR POLLUTION ON LIVESTOCK AND
ANIMAL PRODUCTS 113
EFFECTS ON LIVESTOCK 113
Methods 113
Results 115
Conclusions 122
CONTAMINATION OF LIVESTOCK PRODUCTS 123
8. TRACE-METAL CONCENTRATIONS IN HUMAN HAIR 125
BACKGROUND AND INTRODUCTION 125
MATERIALS AND METHODS 125
RESULTS 126
DISCUSSION 132
SUMMARY 133
REFERENCES FOR CHAPTER 8 133
9. POSSIBLE HAZARDS ASSOCIATED WITH INGESTION OF
GARDEN VEGETABLES CONTAMINATED BY TRACE METALS 135
INTRODUCTION 135
ZINC METABOLISM 135
Balance 135
Toxicity 136
CADMIUM METABOLISM 136
Balance 136
Toxicity 136
ARSENIC METABOLISM 137
Balance 137
Toxicity 137
LEAD METABOLISM 138
Balance 138
Toxicity 138
DAILY CONSUMPTION OF GARDEN VEGETABLES
AND FRUITS 138
ESTIMATED DIETARY LEVELS OF ARSENIC, CADMIUM,
LEAD, AND ZINC 139
SIGNIFICANCE OF DATA 140
SUMMARY 142
REFERENCES FOR CHAPTER 9 143
10. POLLUTION SOURCES 145
INTRODUCTION 145
Emission Summary for Helena Valley 145
East Helena Industrial Complex 146
xiii
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LEAD SMELTING-AMERICAN SMELTING AND
REFINING COMPANY 146
Process Description 146
Emissions 149
Air Pollution Control 151
SLAG PROCESSING-ANACONDA COMPANY 153
Process Description 153
Emissions 154
Air Pollution Control 156
PAINT PIGMENT PRODUCTION-AMERICAN
CHEMET CORPORATION 158
Process Description 158
Emissions and Air Pollution Control 158
11. METEOROLOGY AND SOURCE-RECEPTOR RELATIONSHIPS .. 161
AIR MOVEMENT 161
Wind Stations 161
Wind Direction 162
Wind Speed 163
ATMOSPHERIC STABILITY AND TEMPERATURE INVERSIONS 163
POTENTIAL AIR POLLUTION EPISODE DAYS 167
PRECIPITATION AMOUNTS AND WIND SPEEDS AFFECTING
THE REPRESENTATIVENESS OF THE STUDY PERIOD 168
DIFFUSION ESTIMATES OF MEAN SHORT-TERM S02
CONCENTRATIONS 169
DIFFUSION ESTIMATES OF MEAN LONG-TERM S02
CONCENTRATIONS 172
DISPERSION OF PARTICULATE MATERIAL 174
SUMMARY 178
REFERENCES FOR CHAPTER 11 179
xiv
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HELENA VALLEY, MONTANA,
AREA ENVIRONMENTAL
POLLUTION STUDY
1. SUMMARY
RESULTS AND RECOMMENDATIONS
Atmospheric concentrations of sulfur dioxide in the Helena Valley exceed
Montana air quality standards and levels reported in Federal criteria to be
associated with deleterious effects on human health, vegetation, and materials.
Industrial operations of American Smelting and Refining Company and Ana-
conda Company in East Helena are the responsible sources.
Air, water, and soil in the Valley are contaminated with heavy metals from
the East Helena smelting complex. Water in Prickly Pear Creek is contaminated
by the American Smelting and Refining Company plant. Arsenic, cadmium, and
lead, which are emitted as air pollutants from both plants, settle and accumulate
in soil and on vegetation to an extent surpassing levels that are toxic to grazing
farm animals. Furthermore, evidence indicates that subclinical effects could be
occurring in humans.
Threshold-limit values have been established for industrial exposure of
healthy adults for 8 hours per day, 40 hours per week, during a normal working
life; knowledge is insufficient, however, to establish limits below which heavy
metals may be considered harmless to humans in various states of health who are
exposed to heavy-metal contamination from birth or, through parental contact
with heavy metals in the environment, even before birth. Calculations of total
body burden of lead and cadmium from air, food, and drink, plus evidence of
heavy-metal accumulation in human hair, are sufficient cause for concern and
action to control pollution from the smelting complex in East Helena.
Heavy-metal particulates are not prone to significant dispersion, and tall
stacks will not change the impact of these particles on the Helena Valley.
Increasing the height of emissions is not emission control, in that it removes no
pollution; tall stacks merely spread gaseous pollutants and fine particles for
wider consumption.
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Industrial sources should abate emissions to the lowest practicable levels by
application of modern technology.
Residents of Helena Valley should be informed of possible toxic. effects
from consumption of vegetables or other food items that might be contaminated
either from the soil or from dustfall. All locally grown vegetables should be
washed to remove surface contamination before consumption.
Ranchers within about 5 miles of the smelting complex should be advised of
the danger to low-grazing farm animals like horses and sheep. Such animals
should not graze in fields in the vicinity of East Helena.
INTRODUCTION
In 1888 the Helena & Livingston lead smelter was built at East Helena. The
American Smelting and Refining Company purchased this operation in 1899.
Anaconda Company, in 1927, built a plant adjacent to the lead smelter to
recover zinc from the latter's waste slag. In 1955 The American Chemet
Corporation constructed a nearby paint pigment plant whose raw material is zinc
oxide from the Anaconda zinc plant.
As early as 1901, the American Smelting and Refining Company began
protecting itself against claims for damages to the neighboring premises with
indentures releasing them from such claims.
Lead contamination of the soil has been acknowledged by the management
of American Smelting and Refining Company, as stated by this quotation from a
1963 letter sent to a neighboring rancher by the plant manager:
I have finally received the results of the soil samples and must report
that your soil is highly contaminated with lead. Following are com-
ments on the samples:
Under some circumstances, it is risky to pasture horses on land, the
surface portions of the soil of which contain over 200 parts per million
of lead. This risk is great when grass is grown in soil with a content of
1000 ppm lead. During the times the grass is lush and the animals can
graze in the pasture without cropping low, or without picking up some
soil, I should say the danger would be minimized.
I cannot imagine a very luxuriant growth of vegetation in a pasture
which contains such high concentrations of metals unless the soil is
quite calcareous. Certainly, in this particular area, it would not be "up
to the stirrups" of an ordinary size horse. My advice, therefore, is that
you discourage the use of this pasture for animals, especially for'horses.
Contamination of the air with sulfur dioxide also was acknowledged by
letter from management to a neighboring rancher:
2 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
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During the spring of 1967 and the spring and summer of 1968, your
property south of the smelter has experienced considerable exposure to
S02. Under the present state of knowledge, it is not likely that the
condition can be improved for a matter of years.
Because of this unfortunate situation, it would appear advantageous to
all concerned if you were to move out of that location. Possibly you
can find another location in the countryside and your house could be
moved there.
Please let me know if you are interested so that we can negotiate terms
of sale.
An allegation of heavy-metal contamination of garden vegetables was
brought to the attention of the Food and Drug Administration's Regional
Inspector in Helena on September 20, 1968. This information was relayed from
the Food and Drug Administration to the Consumer Protection and Environ-
mental Health Service. Discussions between Montana health officials and the
Consumer Protection and Environmental Health Service led to an environmental
pollution study of the Helena Valley, Montana, area.
In May 1969, the Memorandum of Agreement that follows was signed by
Federal and State officials.
MEMORANDUM OF AGREEMENT
BETWEEN
THE MONTANA STATE DEPARTMENT OF HEALTH
AND
THE NATIONAL AIR POLLUTION CONTROL ADMINISTRATION
THE FOOD AND DRUG ADMINISTRATION
THE ENVIRONMENTAL CONTROL ADMINISTRATION
(CONSUMER PROTECTION AND ENVIRONMENTAL HEALTH SERVICE,
PUBLIC HEALTH SERVICE,
U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE)
Authority: Under provisions of Section 301 of the Public Health Service Act, as
amended (Public Law 78-410), and Section 103 (a) (3) of the Clean Air Act, as
amended (Public Law 90-148), the National Air Pollution Control Admini-
stration, the Food and Drug Administration, and the Environmental Control
Administration of the Consumer Protection and Environmental Health Service,
Public Health Service, U. S. Department of Health, Education, and Welfare, and
the Montana State Department of Health agree to cooperate in the conduct of a
study of environmental pollution as enumerated in the terms of this memo-
randum.
Title of Project: Helena Valley, Montana, Area Environmental Pollution Study.
Summary 3
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Purpose of Project: To conduct a study of the types, amounts, sources, distri-
bution and effects of environmental pollution in the Helena Valley, Montana
area, with a view to recommending solutions of any problems that are found.
Need for Project: It has been alleged that pollutants arising from man's activities
in the area are contributing to health and welfare endangerment. This study will
provide factual information bearing on the allegations and aid in delineating
solution of any observed problem.
Location of Project: Helena Valley, Montana; specific geographical boundaries
to be determined during field work.
Direction of the Study: Administrative co-direction of the study shall be the
responsibility of Mr. Benjamin F. Wake for the State of Montana, and Mr. Earl
V. Porter for the Federal government.
Arrangements for and coordination of participation by State and Federal
agencies not parties to this agreement shall be the responsibility of the respective
co-directors. Technical direction of each party's personnel shall be by the
designee of each individual agency.
Duration of Federal Participation: Approximately six months' field work, plus
such time as necessary for data analysis and report preparation, unless extension
of the study is agreed to by the parties concerned.
Sharing of Data: Data gathered during the study, because of its possible research
value, shall be freely acessible to all participating agencies. However, data
especially created by the activities of this study, prior to submittal of the final
report, shall be released only after consultation with the Montana State
Department of Health.
Final Report: A report of findings and recommendations will be prepared by the
Federal participants, in consultation with the Montana State Department of
Health. Any of the parties to this agreement may disseminate copies of the final
report in accordance with their regulations and normal procedures.
Special Provisions: Details concerning conduct of various phases of the study
and the roles of individual agency participants will be developed jointly by the
Federal and State parties to this agreement and will be appended, as developed,
to become parts of this agreement.
Investigations for this study were conducted between July 1969 and July
1970.
Background Information
History
In 1864, four prospectors in the hostile reaches of Montana Territory came
4 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
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upon a gulch that they considered to be their "last chance" in their search for
gold. Gold was found in such abundance that a city sprang into existence. Within
1 year this mining community numbered over 100 cabins and was known as
"Last Chance." The main street, running north and south through the center of
town, became "Last Chance Gulch."
In 1882, shortly after the coming of the railroads, Helena became a
corporate city with over 600 citizens voting for a charter.
With the enormous loads of gold being mined in the area, Helena was fast
become the banking capital of the territory. The city soon enjoyed the
reputation of being the wealthiest city per capita in the world.
When Montana Territory was created by Congress in May 1864, the city of
Bannock was the seat of the territory legislature. In 1865, the capital was moved
to Virginia City, another booming miners' town 200 miles to the south of
Helena. By 1875 Helena was the uncontested center of wealth and culture in the
Montana Territory. Shortly thereafter Helena became the capital city.
Prickly Pear Junction, a "way station" on the stage coach route from Ft.
Benton to Helena and other gold camps, became East Helena with the building
of a lead smelter in 1888. In 1899, the American Smelting and Refining
Company purchased the old Helena & Livingston plant. In 1927, the Anaconda
Company installed a zinc plant, and other industries that use smelter by-pro-
ducts settled in the vicinity.
Topography
The Helena Valley in western Montana is an intermountain Valley bounded
on the north and east by the Big Belt Mountains and on the west and south by
the main chain of the Continental Divide. The Valley is approximately 25 miles
in width from north to south, and 35 miles long from east to west. The average
height of surrounding mountains above the valley floor (elevation 3700 feet) is
about 3000 feet.
The city of Helena, with an average elevation of 4100 feet, is located on a
slope at the south side of the Valley. The southern parts of the city have
elevations of about 4300 feet, and the northern parts are at elevations of about
3800 feet.
The city of East Helena is located about 4 miles east of Helena at an
elevation of about 3900 feet. The ground slope is much less evident in East
Helena than it is in Helena. The ground south of East Helena, where the smelting
operations are located, is 30 to 50 feet higher than the city.
The valley floor continues to slope gently to the north and northeast to
Lake Helena, which is located about 10 miles northeast of East Helena. Lake
Helena is the lowest point in the Valley with an elevation of 3650 feet.
Summary
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Climatology
The climate of the Helena Valley may be described as modified continental.
As may be expected in a northern latitude, cold waves may occur from
November through February, with temperatures occasionally dropping well
below zero. Summertime temperatures are moderate, with maximum readings
generally under 90° F and very seldom reaching 100?
Total precipitation varies widely throughout the Valley, from a semiarid
total of 9 to 10 inches in the drier northern and eastern portions of the Valley,
to a subhumid 30 inches along the Continental Divide to the southwest. Most of
the precipitation falls from April through July from frequent showers or
thundershowers, with some steady rains in June, the wettest month of the year.
Late summer, fall, and winter months are relatively dry. Snow can be expected
from September through May. During the winter months snow may remain on
the ground for several weeks at a time. Amounts during the spring and fall are
usually light.
Strong and persistent temperature inversions are common to the Helena
Valley. The surrounding mountains shelter the area from the winds. At night,
cold air drains into the Valley from the surrounding mountain slopes.
Population Statistics
Population statistics for the Helena Valley can be estimated from Helena
and East Helena statistics. There are 125 farms in the Valley. These people may
not be included in the city statistics. Table 1-1 gives population estimates for
Helena and East Helena.
Table 1-1. ESTIMATED POPULATION OF HELENA AND EAST HELENA
Year
1950
1960
1969
Helena
17,581
20,227
26,602
East Helena
1,216
1,490
2,079
Employment
The largest employer in the Helena Valley is the State of Montana. Helena is
the state capital. Retail trade and professional services make the greatest
remaining contribution to employment.
Industry
Heavy industrial manufacturing companies have located within the city of
East Helena. American Smelting and Refining Company operates a custom lead
6 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
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smelter that employs 180 workers. Anaconda Company operates a zinc recovery
plant that employs 80 workers. American Chemet manufactures paint pigments
and employs 10 people. Several miles southwest of the city of East Helena, the
Kaiser Cement and Gypsum Company operates a cement plant that employs 75
workers.
About 20 light industrial manufacturing companies in the city of Helena
employ about 400 people.
Agricultural Activity
There are approximately 220,000 acres of agricultural land on the valley
floor, valued at about $10 million.
Most farming in the Valley is by dry-land practices. The soil is seeded 1
year, left fallow the next, and seeded again the third year. A total of 20,000
acres of wheat and barley is planted each year. The yearly gross income is
estimated to be $300,000 and $200,000 from wheat and barley, respectively.
Four thousand acres of alfalfa is grown on irrigated land with the estimated
worth being about $2 million. Two hundred acres is planted in either corn, oats,
or potatoes, with an approximate value of $9,000. Three thousand acres is used
as seeded or improved pasture, and about 200,000 acres is used as range-land
pasture.
About 700 private gardens are planted in the Valley to produce tomatoes,
beets, carrots, corn, beans, peas, onions, radishes, and cabbage.
There are 15,000 cows and calves in the Valley; their market value is $3
million. Also present are 5,000 sheep and lambs, 5,000 chickens, 1,000 hogs,
and 800 horses, the combined worth of which is estimated at more than
$300,000.
Property Evaluation
Value of properties within the Helena Valley, estimated from the biennial
reports of the State Board of Equalization for Lewis and Clark County, is shown
in Table 1-2.
Review of Previous Pollution Studies
A Study of Air Pollution in Montana, July 1961 to July 1962
There was a study of air pollution conducted by the Montana State Board
of Health from July 1961 to July 1962 with assistance from the Division of Air
Pollution, Public Health Service, U.S. Department of Health, Education, and
Welfare. Limited air quality measurements were made in seven Montana cities.
Total suspended particulate loadings in the city of Helena were reported to
Summary 7
-------
Table 1-2. HELENA VALLEY PROPERTY EVALUATION
(dollars)
Lewis and Clark County
Assessed valuation
Personal property
All real estate, including
improvements town lots . .
Agricultural lands and improvements
Grazing lands
All livestock
All timber
June 30, 1960
80,000,000
30,000,000
40 000 000
6 000 000
3 000 000
2 000 000
70000
June 30,1968
100,000,000
30,000,000
60 000 000
7 000 000
3 000 000
3 000 000
80000
average 72 micrograms per cubic meter (jug/m3) of air. Arsenic, lead, and
fluoride were reported to average 0.08, 0.34, and 0.10 /^g/m3, respectively.
A Study of Air Pollution in the Helena - East Helena Area,
October 1965 to October 1968
Another study of air pollution, from October 1965 to October 1968, was
conducted by the Montana State Department of Health. The objective was to
define the quantity and quality of certain air pollutants in the Helena - East
Helena area.
Monthly average sulfur dioxide (S02) concentrations up to 0.055 part per
million (ppm), hourly averages up to 0.4 ppm, and 5-minute average concen-
trations up to 6 ppm were reported. Suspended particulate loadings averaged 76
iug/m3 in East Helena and 50 to 60 p.g/m3 at various sampling locations in
Helena. Arsenic and lead concentrations were higher in East Helena than in
Helena. The contribution of the smelter complex in East Helena to air pollution
was demonstrated by the decline in sulfation, dustfall, and lead content of
dustfall during a smelter strike.
The study recommendations called for reduction in sulfur dioxide and dust
emissions from the East Helena smelting complex, prohibition of open burning,
and elimination of street dust through paving.
Pollution Study in East Helena, December 1968
In December 1968, a study of pollution in East Helena, financed by the
Montana State Board of Health, was conducted by Dr. C. C. Gordon, Associate
Professor of Botany, University of Montana, Missoula, Montana. The study
objective was to determine the severity and extent of sulfur dioxide damage to
vegetation. The study scope was extended to include an investigation of the
effects of lead and cadmium on the ecosystem.
8 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Dr. Gordon reported that local farmers had stated that raising of horses had
not been feasible for several decades. American Smelting and Refining Company
plant management reportedly has been of the opinion that residents of East
Helena should not eat local garden vegetables because of metal contamination.
Sulfur dioxide effects were found on pine seedlings as far as 4 miles south of
the East Helena smelter complex. Elevated lead and cadmium levels were
reported in garden vegetables and in animal tissues.
ENVIRONMENTAL EVALUATION
Air, water, and soil were examined for contamination by arsenic, cadmium,
lead, and zinc. In addition, airborne sulfur dioxide was measured.
Sulfur Dioxide
Sample averaging time is important in the evaluation of sulfur dioxide
pollution of the air. Unlike generalized air quality deterioration from myriad
emission sources in urban areas, a single source or a few sources in close
proximity will cause a heterogeneous pollutant distribution usually characterized
by infrequent but severe levels. The Helena Valley is subjected to this type of
pollutant distribution, as demonstrated by the range in annual, daily, hourly,
and 1-minute average sulfur dioxide concentrations.
Annual Mean Concentrations
The Environmental Protection Agency's Office of Air Program's best
judgment of effects that occur when various levels of pollution are reached is
reported in AP-50,Air Quality Criteria for Sulfur Oxides. This document states
that:
1. At concentrations of 0.04 ppm, frequency of lung disease may
increase and mortality from bronchitis and lung cancer may occur.
2. At concentrations of 0.03 ppm, chronic plant injury and excessive
leaf drop may occur.
3. At concentrations of 0.12 ppm, the corrosion rate of steel may
increase by 50 percent.
The Montana State Board of Health adopted 0.02 ppm sulfur dioxide
maximum annual average as a statewide ambient air quality standard on May 27,
1967.
The city of Helena experienced 0.01 ppm from June 1969 to June 1970.
Residents of East Helena were exposed to 0.01 to 0.08 ppm, depending upon
their location within the city. Throughout most of East Helena, levels varied
between 0.02 and 0.04 ppm, but a small center-city portion was exposed to
levels between 0.04 and 0.08 ppm. A 20-square-mile area adjacent to and
Summary
-------
southeast of the city of East Helena had levels greater than 0.02 but less than
0.04 ppm. The remainder of the Helena Valley was not exposed to levels greater
than the State standard of 0.02 ppm.
Daily Concentrations
Air Quality Criteria for Sulfur Oxides states that:
1. At concentrations of 0.1 ppm, absenteeism from work and in-
creased hospital admissions of older persons for respiratory disease
may occur.
2. At concentrations of 0.2 to 0.3 ppm, patients with chronic lung
disease may experience accentuations of symptoms, and the gen-
eral population may experience increased mortality.
Montana's statewide sulfur dioxide standard is 0.10 ppm, 24-hour average,
not to be exceeded over 1 percent of the days in any 3-month period.
The concentration equaled or exceeded 0.1 ppm on 4 of the 129 days
sampled (3 percent) in Helena, on 5 of the 128 days sampled (4 percent) in East
Helena, on 15 of the 136 days sampled (11 percent) in the Helena Valley 0.5
mile southeast of the smelter, and on 10 of the 123 days sampled (8 percent) in
the Helena Valley 2.5 miles southeast of the smelter.
Concentrations equaled or exceeded 0.2 ppm on 4 days 0.5 mile southeast
of the smelter and on 1 day at 2.5 miles southeast.
Hourly Concentrations
Air Quality Criteria for Sulfur Oxides reveals that at concentrations of 0.10
ppm sulfur dioxide, in the presence of particulates, visibility may be reduced to
about 5 miles.
Montana's standard is 0.25 ppm, not to be exceeded more than 1 hour in
any 4 consecutive days. In approximately 140 days of sampling in the summer
of 1969, 0.25 ppm was exceeded during 41 hours in Helena, 47 hours in East
Helena, 126 hours in the Helena Valley 0.5 mile southeast of the smelter
complex, and 74 hours in the Helena Valley 2.5 miles southeast of the smelter
complex.
Maximum Concentrations
While the effects of short-term peak concentrations are not discussed in the
Air Quality Criteria Document and although limits are not included in the
Montana State standards, at concentrations greater than 1 ppm the air usually is
so fouled as to cause nausea and coughing in the normal population. The taste
threshold occurs at 0.3 ppm.
10 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
The instruments used during the 140-day sampling period to measure sulfur
dioxide had an upper limit of detection of 4 ppm. The monitor located in
Helena registered greater than 1 but less than 2 ppm for 48 minutes. The
monitor in the city of East Helena registered greater than 2 but less than 4 ppm
for a total of 41 minutes. In the Valley 0.5 mile southeast of the smelter, a
monitor registered greater than 4 ppm for about 2 minutes.
Arsenic
Arsenic compounds are toxic to humans, animals, and plants. Most arsenic
compounds, when heated in air, are converted to arsenic trioxide, a tasteless,
toxic, white powder. Arsenical dusts can produce dermatitis, bronchitis, and
irritation to the upper respiratory tract. Ingestion of arsenic can produce
keratosis and cancer of the skin. The relationship of arsenic to other types of
cancer, particularly lung tumors, is strongly suggestive. Herbivorous animals have
been poisoned from eating plants contaminated with arsenic. Seventy milligrams
of arsenic trioxide has been reported as a fatal dose for man.
Contamination of Air
Maximum permissible atmospheric concentrations have not been adopted in
the United States. A 24-hour standard of 3 Aig/m3 has been recommended in the
U.S.S.R. and Czechoslovakia.
During the summer and fall of 1969, an average 24-hour concentration of
0.005 jug/™3 was found in Helena. Maximum 24-hour concentrations did not
exceed 0.07 Atg/m3 . East Helena was exposed to an average of 0.08, although the
maximum reached 0.3 jug/m3 These values represent the highest found in the
Helena Valley.
The concentration of arsenic in the particulates that settle in the vicinity of
the East Helena smelter is 200 to 1000 ppm. Each month, 1 to 4 milligrams (mg)
of arsenic settle on each square meter of surface area within a 1-mile radius of
the smelter.
Contamination of Water
Arsenic concentrations of 2 to 4 mg per liter are reported not to interfere
with the self-purification of streams. The Montana water quality criteria are
consistent with the Public Health Service Drinking Water Standards that state
that the concentration of arsenic in drinking water should not exceed 0.01 mg
per liter and concentrations in excess of 0.05 mg per liter are grounds for
rejection of the supply.
Sampling of waters in the Helena Valley revealed arsenic in the surface
waters in Prickly Pear Creek, downstream from the smelting complex. On
October 25, 1969, and on April 4, 1970, the surface water in Prickly Pear Creek,
which is 2.5 miles northwest of East Helena, contained 0.01 mg per liter. On the
same dates, Missouri River water at the Helena City Water Plant intake contained
0.02 mg per liter.
Summary 11
-------
Contamination of Soil
The arsenic content of soils ranges from 1 to 50 ppm and averages about 5
ppm. The soil outside, but adjacent to, the Helena Valley contains 6 ppm.
The concentrations of arsenic in the soil decrease with distance from the
smelting complex. At distances of 1 and 2 miles, respectively, the upper inch of
uncultivated soil contains 140 and 23 ppm and the upper 4-inch layer of
cultivated soil contains 40 and 20 ppm.
Cadmium
Cadmium is recognized as an element with high toxic potential. Children
have been made sick by consuming a frozen dessert containing 13 to 15 mg of
cadmium per liter.
Cadmium is absorbed without regard to the level of existing body concen-
trations, which indicates a lack of homeostatic mechanisms for the control of
cadmium levels. It has been reported that the feeding of 0.1 mg of cadmium per
liter causes accumulation of cadmium in the liver and kidney tissues of rats.
Epidemiological evidence associating cadmium with renal arterial hyper-
tension in humans is conflicting.
Contamination of Air
When inhaled, cadmium can produce pulmonary emphysema and bronchitis,
kidney damage resulting in proteinuria, and gastric and intestinal disorders. In
one epidemiological study, air cadmium levels have been associated with cardio-
vascular mortality rates, but this relationship is very tenuous and has not been
confirmed in other studies to date.
Maximum permissible atmospheric concentrations for cadmium have not
been suggested or adopted in the United States. In 1963, the National Air
Sampling Network reported that the nation's air contained an average 24-hour
concentration of 0.002 Mg/m3
The maximum reported individual annual concentration was 0.028 Mg/m3
A maximum 24-hour concentration of 0.18 Mg/m3 was reported in East St.
Louis, Illinois.
During the summer and fall of 1969, the city of Helena was exposed to an
average 24-hour concentration of 0.03 and a maximum 24-hour concentration of
0.11 Mg/m3 The residents of East Helena, depending upon their location within
the city, were exposed to an average 24-hour concentration between 0.06 and
0.29 Mg/m3 and to a maximum 24-hour concentration of 0.7 fig/m3
The concentration of cadmium in the particulate matter that settles in the
vicinity of the East Helena smelter is 200 to 1000 ppm. Each month, 1 to 4 mg
12 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
of cadmium settles on each square meter of surface area within a 1 -mile radius of
the smelter.
Contamination of Water
Recognition of the toxic potential of cadmium when it is taken by mouth is
based on the occurrence of poisoning from cadmium-contaminated food and
beverages, epidemiologic evidence that cadmium may be associated with renal
arterial hypertension, and long-term oral toxicity studies in animals.
According to the Public Health Service Drinking Water Standards, a drinking
water supply containing in excess of 0.01 mg cadmium per liter should be
rejected.
Water was sampled from Prickly Pear Creek (downstream of the smelting
complex) on July 1, 1969; October 25, 1969; and April 4,1970. The cadmium
content was 0.006, 0.001, and 0.007 mg per liter, respectively. Limited sampling
of other Helena Valley waters suggests that the concentration of cadmium
generally is less than 0.001 mg per liter.
Contamination of Soil
The expected cadmium content of soils is 0.5 ppm. The concentration in
the soil outside, but adjacent to, the Helena Valley ranged from less than 0.5 to
2 ppm.
The concentration of cadmium in the soil of the Helena Valley decreases
with distance from the smelter. At a distance of 1, 2, and 4 miles, respectively,
the upper inch of uncultivated soil contains 68, 17, and 4 ppm, and the upper
4-inch layer of cultivated soil contains 21,9, and 3 ppm.
Lead
Lead can be seriously injurious to health as a result of accumulations in the
body. Long-term daily intake of less than 0.6 mg by healthy adults may cause
small increases in body burden, but no clinical disease. An intake in excess of 0.6
mg per day may result in the accumulation during a lifetime of a dangerous
quantity of lead in the body.
Contamination of Air
Because maximum permissible atmospheric concentrations have not been
established in the United States, judgment regarding the significance of lead
contamination must be related to permissible body burden. Intake from the air
can be approximated by assuming 20 percent retention of a daily intake of 20
cubic meters of air.
During the summer and fall of 1969, the city of Helena was exposed to an
average daily concentration of 0.1 jUg/m3, with maximum daily concentrations
Summary 13
-------
up to 0.7 Mg/m3 The residents of East Helena, depending upon location^within
the city, were exposed to an average daily concentration of 0.4 to 4 /Jg/m , with
maximum daily exposures up to 15 /-tg/m3
Daily respiratory intake in Helena is calculated to be 0.5 jug. In East Helena,
the daily respiratory intake varies from 2 to 20 /ug, depending upon location
within the city.
Particles that settle from the air in the vicinity of the smelter contain 6,000
to 28,000 ppm. Ingestion of 0.007 to 0.04 ounce of these particulates may
exceed the daily body-burden limit.
Within a 1-mile radius of the East Helena smelter, 30 to 140 mg of lead
settles in particulate form each month on each square meter of surface area.
Accordingly, each 0.5 to 2 square feet of surface area is contaminated each
month by an amount equivalent to the daily body-burden limit for lead.
Contamination of Water
The lead concentration in drinking water supplies ranges from traces to 0.04
mg per liter, averaging 0.01 mg per liter. At concentrations of 0.1 mg per liter,
bacterial decomposition of organic matter is inhibited and some fish are
susceptible to lead poisoning. Adults consume 1 to 3 liters of drinking water per
day.
The Public Health Service Drinking Water Standards state that 0.05 mg of
lead per liter constitutes grounds for rejection of the water supply.
Helena Valley waters contain less than 0.001 to 0.04 mg per liter. The water
in Prickly Pear Creek contained 0.044, 0.000, and 0.042 mg per liter on July 1,
1969, October 25, 1969, and April 4,1970, respectively. Missouri River water at
the Helena City Water Plant intake contained 0.033, 0.000, and 0.019 mg per
liter on those respective dates.
Contamination of Soil
The expected lead content of soil is 16 ppm. The concentration in soil
outside, but adjacent to, the Helena Valley is 15 ppm. The concentration in the
soil of the Helena Valley decreases with distance from the smelting complex. At
distances of 1,2, and 4 miles, respectively, the upper inch of uncultivated soil
contains 4,000, 600, and 100 ppm, and the upper 4-inch layer of cultivated soil
contains 700, 250, and 90 ppm.
Zinc
Zinc is a normal constituent of the human body. It is taken into the body in
the diet or by inhalation, and is eliminated by processes of excretion and
perspiration. Excessive body intake, however, can result in zinc poisonin".
14 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Contamination of Air
Inhalation of zinc does not represent a significant health risk to the general
population, but it is of concern in the field of occupational health. Exposure to
air containing milligram quantities per cubic meter has resulted in metal-fume
fever, a malaria-like illness that lasts about 24 hours and has never been known
to be fatal.
Maximum permissible atmospheric concentrations for zinc have not been
established. The 1967 American Conference of Governmental Industrial Hy-
gienists adopted the value of 5 milligrams per cubic meter (mg/m3) for zinc
oxide fumes in occupational exposures.
During the summer and fall of 1969, airborne zinc in the Helena Valley,
depending upon location, averaged less than 0.1 to 3 Mg/m3, with maximum
24-hour values up to 8 [Jtg/m3
Contamination of Water
Zinc salts act as gastrointestinal irritants. Although the illness may be acute,
it is transitory. The emetic concentration in water is 1 gram per liter.
Communities have used waters containing up to 27 mg per liter without harmful
effects.
Concentrations of about 30 mg per liter impart a milky appearance and a
metallic taste. Concentrations below 4 mg per liter generally are not detectable
by the human sense of taste.
Inasmuch as zinc in water does not cause serious effects on health but
produces undesirable esthetic effects, it is recommended that concentrations of
zinc be kept below 5 mg per liter.
Water supplies within the Helena Valley were found to contain 0.003 to
0.2 mg per liter.
Contamination of Soil
The expected zinc content of the soil is 44 ppm. The concentration in soil
outside, but adjacent to, the Helena Valley is 58 ppm. The concentration of zinc
in the soil of the Helena Valley decreases with distance from the smelting
complex. At a distance of 1 mile, the upper inch of uncultivated soil and the
upper 4-inch layer of cultivated soil contain 1,100 and 300 ppm. respectively,
whereas at a distance of 2 miles from the complex both soils contain 200 ppm.
EVALUATION OF POLLUTANT EFFECTS
Vegetation
Leaf damage and contamination can be attributed to specific pollutants.
Suppression of growth rate may occur as a result of pollution. From studies
conducted during the summer of 1969, it was concluded that the vegetation
Summary 15
-------
growth rate was suppressed 15 percent in the vicinity of the city of East Helena.
Damage from Sulfur Dioxide
Within 1 mile of the smelter complex, sulfur dioxide leaf damage to
indigenous alfalfa, corn, sweet potato, lettuce, tomato, grape, apple, and plum
occurred during the summer of 1969.
Sulfur dioxide damage was identified histologically on pine trees growing
within 0.5 mile of the smelter complex during 1969. In 1968, this type of
damage was found at distances up to 4 miles from the smelter complex.
Arsenic Contamination
The tolerance for arsenic on sprayed fruits and vegetables set by the Food
and Drug Administration is 3.5 ppm. Lettuce, carrot, beet, pinto bean, and
alfalfa grown in the city of Helena in 1969 had an average arsenic content of 0.4
ppm.
Concentrations in edible portions of unwashed vegetables and crops grown
in 1969 within a 4-mile radius of East Helena varied from 0.05 to 14 ppm on a
wet basis. Pasture grass, barley straw, and alfalfa contained 0.4 to 14 ppm.
Barley, wheat, and oat kernels contained 0.05 to 0.9 ppm. Onion, lettuce,
carrot, and cabbage had maximum concentrations of 0.9 to 3 ppm. Apple, beet,
kohlrabi, potato, radish, rutabaga, string bean, and garden peas had maximum
concentrations of 0.05 to 0.5 ppm.
Cadmium Contamination
Lettuce, carrot, beet, bean, and alfalfa grown in the city of Helena during
1969 had an average cadmium content of 0.7 ppm.
The concentration in edible portions of unwashed vegetables and crops
grown in 1969 within a 4-mile radius of East Helena varied from 0.05 to 10
ppm. Pasture grass, alfalfa, and barley straw contained 0.1 to 10 ppm. Barley,
wheat, and oat kernels contained 0.1 to 1.5 ppm. Lettuce and beet maximum
concentrations were 3.4 and 2.5 ppm, respectively.
Lead Contamination
Lettuce, carrot, beet, bean, and alfalfa grown in the city of Helena during
1969 had an average lead content of 1 ppm.
Concentrations in edible portions of unwashed vegetables and crops grown
in 1969 within a 4-mile radius of East Helena varied from 0.1 to 100 ppm.
Pasture grass, barley straw, and alfalfa contained 1.4 to 100 ppm. Barley, wheat,
and oat kernels contained 0.1 to 10 ppm. Lettuce, beets, and cabbage had
maximum concentrations of 17, 15, and 9 ppm, respectively.
16 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Zinc Contamination
Lettuce, carrot, beet, bean, and alfalfa grown in the city of Helena in 1969
had an average zinc content of 12 ppm.
Concentrations in edible portions of unwashed vegetables and crops grown
in 1969 within a 4-mile radius of East Helena varied from 0.5 to 230 ppm.
Pasture grass, barley straw, and alfalfa contained 23 to 124 ppm. Barley, wheat,
and oat kernels contained 23 to 86 ppm. Beet, lettuce, carrot, and garden peas
had maximum concentrations of 68, 36, 36, and 22 ppm, respectively.
Animals
Systematic investigation of health abnormalities caused by air pollutants
was not feasible during this study. Accumulation of heavy metals in hair, in
organs, and in edible animal tissue was investigated.
Acute Effects on Health
Horses are more susceptible than other species of farm animals to the
environmental toxicants that occur within the Helena Valley. The 1969
post-mortem report on a 3-year-old bay mare reads:
10/12-about 4 pm on horse reported to have clinical signs of
"smoked" horse syndrome. Frothy nasal exudata, congestion and
consolidation in lungs with varying degrees of hepatization, grossly; not
the severity of lung damage as seen in some previous cases on ranch. All
other systems (no nervous exam) appeared grossly normal.
This report is consistent with chronic lead and/or cadmium exposure, pneu-
monia primary or secondary to heavy-metal exposure, and/or heart disease
primary or secondary to heavy-metal exposure. The presence of toxic levels in
the kidney (300 ppm cadmium and 3 ppm lead) and in the liver (80 ppm
cadmium and 4 ppm lead) but not in the mane, indicates an acute rather than a
long-term or chronic exposure.
Heavy-Metal Accumulation in Hair
Hair is a depot for arsenic, cadmium, and lead during long-term exposure to
these metallic toxicants. Increasing levels of arsenic, cadmium, and lead in the
manes of horses of the Helena Valley correlate with proximity to the smelter
complex. Older horses, horses residing in the Valley for the longest duration, and
chronically impaired horses have the highest concentrations of lead and cad-
mium. A significant percentage of the horses exhibit lead and cadmium levels
that are two to five times the usual concentrations of cadmium and lead in horse
mane hair.
Heavy-Metal Accumulation in Organs
Livers and kidneys of uncaged domestic rabbits living within 0.5 mile of the
smelter complex contained elevated levels of cadmium and lead. Cadmium
Summary 17
-------
content of the livers from different rabbits varied from 4 to 9 ppm, and content
of the kidneys varied from 20 to 60 ppm; the usual cadmium content is
approximately 0.1 ppm for liver and 0.3 ppm for kidney. Lead content of the
livers varied from 3 to 8 ppm, and content of the kidneys varied from 2 to 19
ppm; the usual lead content is less than 0.1 ppm.
Liver and kidney tissues of mice living in the Helena Valley also contained
increased levels of cadmium and lead. The average cadmium content of liver
tissue varied from 0.4 to 5 ppm, and the content of kidney tissue ranged from
1.5 to 14 ppm. Liver and kidney tissue of similar animals caught outside, but
adjacent to, the Valley averaged 0.2 and 2 ppm cadmium, respectively. In liver
tissue, the average lead content varied from 2 to 15 ppm and in kidney tissue,
from 2 to 110 ppm. Liver and kidney tissue of similar animals caught outside,
but adjacent to, the Valley both averaged 0.5 ppm lead.
Heavy-Metal Accumulation in Animal Foodstuffs
Delayed opening of a local slaughterhouse limited the evaluation of the
hazard of foodstuffs derived from the animal population to samples that could
be collected from local farms. Beef, swine, chicken, and rabbit muscle within 2
miles of the smelting complex contained maximum concentrations of 0.6 ppm
arsenic, 0.4 ppm cadmium, 0.5 ppm lead, and 70 ppm zinc. Whole milk was
found to contain a trace quantity of arsenic, 0.02 ppm of cadmium, 0.06 ppm of
lead, and 5 ppm of zinc.
Humans
Investigation of air-pollution-related health impairment in the residents of
the Helena Valley was not within the scope of this study. Investigations were
made, however, of heavy-metal accumulation in human hair and body burdens
of heavy metals.
Heavy-Metal Accumulation in Hair
The exposure of the residents of the Helena Valley to heavy metals was
reflected by elevated concentrations of arsenic, cadmium, and lead in the hair of
fourth-grade school boys. Elevated levels of these metals in hair have not been
associated with any clinical illness in these children.
Average and maximum heavy-metal levels in hair are listed by city in Table
1-3.
Body Burden
Acceptable daily intake of trace metals is based upon analysis of common
foodstuffs, air, and water and upon excretions. Estimated maximum daily intake
levels for arsenic, cadmium, lead, and zinc are 0.9, 0.2, 0.4, and 13.0 milligrams,
respectively.
The diet represents the major source of body intake of these heavy metals;
18 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 1-3. HEAVY-METAL LEVELS IN HAIR FOR THREE CITIES
(ppm)
East Helena
Helena
Bozeman3
Arsenic
Average
5.2
0.8
0.4
Maximum
30
1
1
Cadmium
Average
2.0
1.3
0.9
Maximum
6
6
3
Lead
Average
43
12
8
Maximum
175
75
22
aBozeman, a neighboring city not believed to be influenced by contamination,
is listed for the sake of comparison.
however, in areas of high contamination, ingestion of soil or dirt also may be a
consideration. In East Helena, ingestion of 10 milligrams (0.0004 ounce) of the
airborne settleable participates will double the acceptable daily intake of lead.
The ingestion of 200 milligrams of such particulate matter will result in an
intake of cadmium that is double the acceptable level.
Assuming that garden vegetables contain heavy-metal contaminants equiva-
lent to the maximum measured, and that garden vegetables provide the entire
dietary souce of vegetables on a continuing basis, calculations indicate that the
body burden will be exceeded for cadmium and lead. Tissue accumulation is to
be expected. Although no acute health hazard is indicated, concern must be
given to the effects that might occur following continuous exposure to these
levels of cadmium and lead.
POLLUTANT SOURCES
Annually, industrial processes in the Helena Valley are the source of
approximately 80,000 tons of sulfur dioxide and 6,000 tons of particulate
matter. Additional particulates are also emitted from unpaved roads.
Industries of the East Helena smelting complex contribute the bulk of air
pollution found in the Helena Valley. This complex consists of the lead smelter
of the American Smelting and Refining Company, the zinc oxide plant of the
Anaconda Company, and the paint pigment of the American Chemet Corpo-
ration.
The East Helena smelter of the American Smelting and Refining Company
converts mineral ore to usable metal. Lead concentrates and crude ore are
brought to the plant by rail. Ore concentrates contain 50 to 70 percent lead and
10 to 30 percent sulfur. Gondola cars (about 8 per day) are unloaded with a
backhoe onto moving belts that carry the material up to receiving bins. Crude
ore is put through a crusher before being put into a bin. Concentrates are mixed
with zinc residues, limestone, and siliceous ore; the material is pelletized and
then delivered by belt conveyor to the sintering plant, where the mixture is
fused by burning off the sulfur. The resulting sintered ore concentrate is mixed
Summary
19
-------
with coke and charged into the top of a blast furnace. The charge, about 1,000
tons of material per day, is ignited, melted, and reacted to form lead bullion and
slag. Lead and slag flow from the furnace continuously into a brick-lined settler.
Slag overflows the settler into slag pots and is transferred by rail either to the
Anaconda zinc oxide plant or to the slag pile. Lead bullion is tapped into pots
and transferred by rail to the dressing plant. In the dressing plant, the lead is
poured into one of several large (90-ton) kettles and allowed to cool. Copper,
having a higher melting temperature, crusts or drosses. The dross floats on top
and is skimmed off; after being mixed with soda ash and coke breeze, the dross
is transferred to a reverberatory furnace where it is smelted for further
separation of zinc and lead according to density. Molten lead flows to the
bottom and a layer of slag floats to the top. Just under the slag, copper matte
(metal sulfides) forms, and copper speiss (metal arsenides and antimonides)
settles just over the molten lead. The matte and speiss are cooled and shipped
out of the area to a copper recovery plant. Molten lead is recycled to the
dressing kettles. Lead in the dressing kettle is further purified by the addition of
sulfur and by cooling, which results in further removal of copper as matte. The
lead is then cast into 10-ton ingots and shipped out of the area to a lead refinery.
The zinc oxide plant of the Anaconda Company recovers zinc from the lead
smelter slag. Daily, 100 tons of zinc oxide is recovered from approximately 500
tons of smelter slag. Molten slag received directly from the lead smelter or from
cold storage is transported by rail in large pots and dumped into the top of a
furnace. Pulverized coal and air forced into the bottom of the slag bath heat the
mixture to 2,200° F. Zinc is vaporized, oxidized, and drawn from the furnace
through a flue-and-cooling system, where the oxides solidify. The air stream
bearing the solid oxides is forced through a baghouse that collects the zinc
oxide. Molten slag, drawn from the bottom of the furnace into pots, is taken by
rail and dumped on the waste slag pile.
The paint pigment plant of the American Chemet Company modifies zinc
and copper oxides. Daily, 15 tons of zinc oxide from the zinc fuming plant is
heated with natural gas in rotary kilns to improve the whiteness quality by
removing traces of coal and by reacting any remaining sulfur. This product is
then pulverized and packed in bags for outside distribution. Additionally, up to
100 tons per day of zinc oxide from a different source can be pulverized. This
plant also has the capacity to produce 150 tons per day of cupric oxide
pigments. Crude cupric oxide is reduced in a closed retort, milled, and packaged
for distribution.
Sulfur Dioxide Emissions
The East Helena lead smelter and zinc recovery plants collectively account
for 99 percent of the Helena Valley sulfur dioxide emissions.
Lead Smelter
During the normal production rate of 1,200 tons of feed per day, the
smelter emits 330 tons of sulfur dioxide. The charge stock contains up to 30
20 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
percent sulfur, of which 89 percent is released during the sintering operation, 4
percent is released from the blast furnace, and 7 percent remains with the slag.
Small amounts are released from the slag dump, the dressing plant, and the
reverberatory furnace. Off-gases from the sintering operation pass through an
electrostatic precipitator for dust removal and are discharged to the atmosphere
from a 400-foot stack. Off-gases from the blast and reverberatory furnaces are
combined, pass through a baghouse, and are discharged into the atmosphere at
an elevation of 117 feet.
No attempt is made to curtail emissions by either recovery or removal of
sulfur from the gaseous emissions. In July 1970, the Montana State Board of
Health adopted an emission standard stating that within 3 years the amount of
sulfur that may be released into the atmosphere in gaseous form must be less
than 10 percent of the amount contained in the process raw material.
The 400-foot stack is used to reduce the impact of emissions from the
sintering operation at ground level near the smelter. In the spring of 1970, an
induced draft fan and stack heater were added to reduce such impact further.
Three ground-level sulfur dioxide monitoring stations are operated in the smelter
area by the American Smelting and Refining Company. Reportedly, if a monitor
detects a concentration of 0.7 ppm that persists for 15 minutes, the sintering
plant is shut down and is not started up until the monitor indicates a
concentration of less than 0.5 ppm for 15 minutes.
Sulfur dioxide emissions from the sintering operation can be reduced by
conversion to and recovery as sulfuric acid, by conversion to and recovery as
sulfur, or through removal by scrubbing. Sulfur dioxide emissions from the
baghouse can be reduced by a limestone scrubber.
Zinc Recovery Plant
Operating at a production rate of 100 tons of product per day, the plant
emits 13 tons of sulfur dioxide. The raw material is 2 percent sulfur, and the
resulting waste slag is 1 percent sulfur. Sulfur dioxide is emitted from the
charging of the furnace, from the baghouse, and from the slag pile.
Sulfur dioxide emitted from the baghouse and from furnace charging can be
reduced by cleaning the effluent with a limestone-type scrubber. Emissions from
the slag-dumping operation can be eliminated by the use of a granulating-type
operation in which the molten residue slag is quenched by a stream of water,
inside an enclosure, and the effluent gases are vented to a limestone scrubber.
Source-Receptor Relationships
Estimates of contributions from individual sources to the ambient pollutant
concentrations were made using sulfur dioxide emission data and meteorological
measurements of air movement. Sources considered were the zinc fuming plant
baghouse, the smelter baghouse, and the 400-foot stack from the smelter.
Depending upon atmospheric stability, the point of maximum impact of the
Summary 21
-------
baghouses generally will occur at distances of 0.2 to 2 miles from the source.
The maximum 1-hour sulfur dioxide concentrations expected are 0.6 to 0.9 ppm
from the Anaconda baghouse and 1 to 3 ppm from the smelter baghouse. The
maximum point of impact from the 400-foot stack can occur at distances of 0.4
to 31 miles, and respective 1-hour values of 5 and 0.2 ppm can be expected. The
maximum point of impact from the 400-foot stack when heater and fan are
operating will occur at distances of 0.5 to 43 miles, and concentrations of 2 and
0.1 ppm, respectively, can be expected.
Aerodynamic downwash of the baghouse emissions is expected to cause
concentrations in excess of 8 ppm whithin the city of East Helena.
Diffusion calculations of annual mean concentrations, neglecting downwash
phenomena, throughout the Helena Valley predict that: 75 percent of the
atmospheric sulfur dioxide in Helena originates from the 400-foot stack (with
fan and heater); 85 percent of the atmospheric sulfur dioxide in East Helena
originates from the baghouses; and 50 percent of the atmospheric sulfur dioxide
in the area southeast of the city of East Helena originates from the 400-foot
stack.
Particulate Emissions
Industrial processes and fuel use account for 98 percent of the estimated
particulate emissions. Unpaved streets in the area emit an unknown quantity of
particulates; the seriousness of these emissions is compounded by the number of
unpaved streets in use and by the cadmium and lead contamination of road dirt
in East Helena.
Lead Smelter
When operating at a normal production rate of 1,200 tons of feed per day,
the smelter is estimated to emit 1,000 pounds of particulate matter that contains
substantial concentrations of arsenic, cadmium, lead, and zinc. Known points of
emission include the material-receiving area during unloading of concentrates,
the outside yard area used for storage of concentrates, and the baghouse through
which off-gases from the sintering furnace pass to the atmosphere.
Only minimal efforts have been made by the company to control emissions
from material handling. Particulates in the off-gases of the blast and reverber-
atory furnaces are estimated to be 99 percent controlled by the baghouse.
Particulates in the off-gases of the sintering furnace are controlled by an
electrostatic precipitator reported to be 97 percent efficient, but the reported
efficiency is questionable because of the age of this precipitator.
Zinc Recovery Plant
Quantitative estimates of emissions are not available; but known points of
emissions are the furnace, the baghouse, the slag dump, and the coal pulverizer.
When slag is charged into the furnace, copious emissions of white fumes,
22 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
believed to contain high concentrations of cadmium, lead, and zinc, are emitted
at the charging door. The product, zinc oxide, is collected by a baghouse with a
high collection efficiency. Disposal of slag is estimated to emit in excess of 1 ton
per day of particulate matter, and coal crushing emits a sizable but undeter-
mined quantity of coal dust.
The company has made no efforts to control particulate emissions from the
charging of the furnace and from the dumping of slag. A baghouse has been
installed to control emissions from the coal crusher.
Source-Receptor Relationships
Neither the amounts nor the physical and chemical properties — such as
size, shape, density, and chemical content — of particles emitted by industrial
sources in East Helena are known. Quantitative estimates cannot be made,
therefore, of the distribution of particles and heavy metals at ground level.
Unlike gases, particulates attain some downward settling velocity. Accordingly,
maximum ground-level airborne particulate and heavy-metal concentrations
occur closer to the sources than do the maximum concentrations predicted for
sulfur dioxide.
Waste Water Emissions
Lead Smelter
Plant effluent, consisting of cooling water and process wash water, is
discharged into holding ponds that connect with Prickly Pear Creek. Cooling
water is cycled at a rate of 1,450 gallons per minute between the plant and the
retention ponds. Water from the washing of speiss is discharged into the ponds
for a period of 1 hour per day at a rate of 600 gallons per minute.
Speiss wash water is high in heavy-metal content. Analysis by the State of
Montana of the pond discharge into the creek indicates the following metals and
their concentrations in parts per million: arsenic, 0.8; copper, 1.1; lead, 0.6; and
iron, 1.1.
Zinc Oxide Plant
Process and cooling water from this facility is held in ponds for recircu-
lation, with no discharges being made into Prickly Pear Creek or any other
portion of the Valley's drainage system.
Solid Waste Disposal
Lead Smelter
Process slag from past operations is stored on plant property near Prickly
Pear Creek. Upon demand, this slag is taken to the zinc oxide plant for further
processing.
Summary 23
-------
Zinc Oxide Plant
The waste slag is taken in pots by rail and dumped on the large waste-slag
pile located between the smelting complex and the city of East Helena.
24 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
2. SURVEY OF AIRBORNE POLLUTANTS
Norman A. Huey
ENVIRONMENTAL PROTECTION AGENCY
REGION VIII OFFICE
INTRODUCTION
The pollutants surveyed in the study area were sulfur dioxide, airborne
particulates, arsenic, cadmium, lead, and zinc. All measurements were made
between June and November 1969 except for sulfation measurements, which
were continued until June 1970.
Sulfur dioxide was measured with continuous monitors at 5 locations and
with sulfation plates1 at approximately 200 locations. Measurements related to
sulfur dioxide pollution, i.e., sulfate and total acidity, were also made on
suspended particulates.
Total suspended and total settleable particulates (dustfall) were measured at
5 locations; windblown particulates and soiling index were measured at 40 and 4
locations, respectively.
Arsenic, cadmium, lead, and zinc contents were determined in suspended
and settleable particulates.
Ozone and nitrogen oxides were measured by continuous monitors for brief
periods of time at one or two locations in conjunction with the vegetation-effect
investigations.
SULFUR DIOXIDE
Point Measurements of Sulfur Dioxide
From June to November 1969, continuous monitors (Beckman* 906
coulometric instruments) were operated at sampling stations 1, 2, 3, 4, and 5
shown in Figure 2-1.
The results from these instruments were reduced manually in the field by
the operating personnel. The number of occurrences and the length of each
occurrence that each instrument indicated was greater than preselected sulfur
dioxide levels were recorded daily. This information is summarized for the entire
sampling period in Table 2-1. These data are presented to show that infrequent,
short-term, high levels of sulfur dioxide occur. Levels in excess of 2 parts per
*Mention of a specific company or product does not constitute endorsement
by the Environmental Protection Agency.
25
-------
to
ON
tn
r
m
2
2
W
z
H
>
r
^
o
EAST HELENA
C/3
H
O
Figure 2-1. Sulfur dioxide monitoring locations.
-------
t/J
I
I
ft)
I
5?
Table 2-1. NUMBER OF OCCURRENCES AND LENGTH OF TIME SPECIFIC LEVELS EXCEEDED
Sampling
station
1
2
3
4
5
Number of times and number of minutes specific levels exceeded
>4 ppm
times
0
0
1
0
0
minutes
0
0
2
0
0
>2 ppm
times
11
8
66
0
0
minutes
41
33
388
0
0
>1 ppm
times
32
31
148
4
3
minutes
186
175
1075
48
7
XD.5 ppm
times
52
101
314
19
27
minutes
579
723
2563
273
143
>0.2 ppm
times
109
264
533
76
74
minutes
1447
2413
6182
1358
1036
> 0.1 ppm
times
159
408
663
155
112
minutes
2867
5195
10,311
4041
2446
<0.1 ppm
times
—
-
-
-
-
minutes
117,063
161,225
174,539
174,509
159,444
-------
million (ppm) were measured at sampling sites 1,2, and 3. At sampling site 3, 2
ppm S02 was exceeded on 66 occasions for a total time of 388 minutes, or for
about 6 minutes per occurrence. Sampling sites 1 and 3 represent the range of
pollution that might be expected in East Helena. Sampling site 4 is represen-
tative of Helena.
The recorder strip-charts from these same monitors were later further
reduced to produce 10-minute average concentrations. Using these values as
input, a computer produced the frequency distribution of daily, hourly, and
10-minute values for each sampling location (Figures 2-2 through 2-6).
Spatial Distribution of Sulfur Dioxide
To improve the estimates of sulfur dioxide pollution throughout the entire
Valley, 200 sampling stations using sulfation plates1 were established. Sulfation
measurements were made monthly from June through November of 1969.
Sulfation measurements after November were made on a 3-month basis until
June 1, 1970. The sulfation results were used as input to an IBM 1130 scientific
computer. The computer, utilizing an IBM contour-mapping software package
and a CAL-COMP plotter, was instructed to draw maps showing the distribution
of sulfur dioxide throughout the Valley. Figures 2-7 through 2-16 were made
from these computed maps. Figure 2-7 is a map of the sulfur dioxide pollution
from June 1969 through May 1970. The map indicates that a small area in the
center of the city of East Helena was polluted to a level greater than 0.04 ppm
sulfur dioxide annual average. A larger area (approximately 10 square miles)
lying adjacent to and southeast of East Helena was polluted to a level greater
than 0.02 ppm S02.
Figure 2-8 is a map of the spatial distribution of sulfur dioxide during the
active study period. The period covered includes the months of July, August,
September, and October 1969. June 1969 was not included since during that
month the plants of the industrial complex were operating only 50 percent of
the time.
Figures 2-9 through 2-14 present the spatial distribution by month from
June to November 1969. Figure 2-9, representing June 1969, shows a great
contrast in pollution when compared to other months. Figure 2-14 indicates that
the sulfur dioxide pollution increased dramatically between October and
November. Figure 2-15 represents the spatial distribution of sulfur dioxide
pollution during the winter months of December 1969, January 1970, and
February 1970, indicating that the ambient air quality remained equivalent to
the November 1969 level. During the spring months (Figure 2-16), the air
quality improved.
The sulfation values were converted to sulfur dioxide values by means of the
relationship: 1 mg S03/100 cm2-day is equivalent to 0.035 ppm SO2 .2 >3 This
empirical relationship was derived from numerous parallel sulfur dioxide and
sulfation measurements made in other studies. The validity of this relationship is
verified for the Helena Valley area by comparison of the sulfation measurements
made in the vicinity of the continuous monitors.
28 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
30 20 10 5 21 0.5 0.2 0.1 0.05 0.01
PERCENT OF VALUES GREATER THAN INDICATED CONCENTRATION
Figure 2-2. S02 frequency distribution at sampling location 1.
Survey of Airborne Pollutants
29
-------
10-MINUTE VALUES
60 MINUTE VALUES
0.01
~30 20 10 5 21 0.5 0.2 0 1 0 05 0.01
PERCENT OF VALUES GREATER THAN INDICATED CONCENTRATION
Figure 2-3. S02 frequency distribution at sampling location 2.
30 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
30 20 10 5 21 0.5 0.2 0.1 0.05 0.01
PERCENT OF VALUES GREATER THAN INDICATED CONCENTRATION
Figure 2-4. S02 frequency distribution at sampling location 3.
Survey of Airborne Pollutants 31
-------
0.01 I
30 20 10 5 21 0.5 0.2 0 1 0.05 0.01
PERCENT OF VALUES GREATER THAN INDICATED CONCENTRATION
Figure 2-5. S02 frequency distribution at sapling location 4.
32 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
10-MINUTE VALUES
60-MINUTE VALUES
30 20 10 5 21 0.5 0.2 0.1 0.05 0.01
PERCENT OF VALUES GREATER THAN INDICATED CONCENTRATION
Figure 2-6. SOn frequency distribution at sampling location 5.
Survey of Airborne Pollutants 33
-------
OJ
a
tn
t-1
tn
>
>
r
r
tn
!-<
tn
o
§
tn
2
H
s
r
H
C/5
H
G
O
Figure 2-7. Annual average spatial distribution of S02, June 1969 through May 1970.
-------
§
a
a
*e
o
c
r-f
W
W
Figure 2-8. Study period spatial distribution of SC>2, July through October 1969.
-------
ON
a
w
w
z
r
w
§
o
z
§
3
>
r
"a
O
r
H
h-^
O
z
(/3
H
a
0.01
0.01
01234
0.01
0.01*
0.01
Figure 2-9. Spatial distribution of SC>2 during partial plant shutdown, June 1969.
-------
C/Q
s
>
t?"
O
a
o,
sT
<-f-
B5
3
Figure 2-10. Spatial distribution of S02, July 1969-
-------
w
oo
ffl
W
r
w
r
w
w
2
£
)j>-
r
•d
0
r
r
c
H
0
2
OT5
H
G
Ppm S02
^J> 0.01
(ffl)>0-02
U J»if
0>0.04
Figure 2-11. Spatial distribution of SO2, August 1969.
-------
C/3
1
a*
o
3
a
B-
(m>o.o2
£3>0.04
di|>0.08
0
0 -
0
\
Figure 2-12. Spatial distribution of SC>2, September 1969.
-------
a
w
r
w
z
o
z
r
r
o
z
G
a
' ••-•••':•-,• !.v..rv
Figure 2-13. Spatial distribution of SO2, October 1969.
-------
CX3
o
!-*>
>
3"
o
II
n
IB
o
3
r-t-
CM
Figure 2-14. Spatial distribution of S02, November 1969 (1 month after end of study period).
-------
K)
S3
W
I-1
§
H
>
r
s
G
H
H
G
O
Figure 2-15. Winter spatial distribution of SO2, December
1969 through February 1970.
-------
O4
o
l-t
n
"B
£_
5*
r-t-
63
p-t-
(/>
Figure 2-16. Spatial distribution of S02, March through May 1970.
-------
Table 2-2 contains the sulfation predictions along with the measured sulfur
dioxide values. The predicted values are in agreement generally within 0.01 ppm
of the measured values. The degree of validity of the measured values is not
known precisely; however, it is unlikely that they would deviate from the true
value by as much as 0.01 ppm. Accordingly, it should be concluded that any
individual sulfation value in this area is capable of predicting the true average
sulfur dioxide level within 0.01 ppm.
Table 2-2. COMPARISON OF SULFATION PREDICTIONS
WITH MEASURED PPM VALUES
(ppm)
Month
June
July
August
September
October
Mean
Sampling station
1
xa
0.01
0.04
0.04
0.03
0.01
0.02
vb
0.01
-
0.03
0.04
0.02
0.03
2
X
0.00
0.03
0.03
0.05
0.04
0.03
y
0.01
0.05
0.03
0.06
0.05
0.04
3
X
0.01
0.06
0.04
0.04
0.05
0.04
y
0.01
0.07
0.02
0.05
0.06
0.04
4
X
0.00
0.01
0.02
0.02
0.02
0.01
y
0.00
0.01
0.01
0.02
0.03
0.01
5
X
0.00
0.02
0.01
0.01
0.01
0.01
y
_
-
-
0.01
0.02
0.01
ax = ppm value from monitor.
y = ppm value predicted from sulfation.
Long-Term Trends
Figure 2-17 is a graphical representation of the monthly sulfur dioxide levels
experienced at the East Helena City Hall from July 1968 through November
1969. These values were estimated from sulfation data.3 Over the entire period
of time, the sulfur dioxide averaged 0.10 ppm, with monthly fluctuations
ranging from 0.04 to 0.18 ppm. This high variability is typical of areas with large
point sources. Five of the six active sampling months (June through November
1969) are below the average for the entire period. It should be concluded that
sulfur dioxide pollution in the 1969 summer period was lower than it had been
in the previous year.
Sulfur Dioxide Related Measurements
Total acidity and sulfate content of suspended particulate matter are
considered to be sulfur dioxide related. Particulate sulfate and total acidity
measurements were made of the total suspended particulate samples that were
collected on glass-fiber filters.
44 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
0.18
0.16
0.14
0.12
1 0.10
o.oe
0.04
0.02
Jy Au Se Oc No De Ja Fe Mr Ap My Ju Jy Au Se Oc No
1968 1969
Figure 2-17. Sulfur dioxide trend from July 1968 to November 1969.
Table 2-3 contains summary statistics concerning the sulfate content of
suspended particulate matter. These results are considerably below the national
average and serve to point out that there is no problem from sulfates. It should
also be noted that the sulfate content is evenly distributed among the five
sampling stations, which indicates that there is no significant increase in con-
centration in the vicinity of the East Helena industry.
Table 2-4 contains summary statistics concerning the total acidity of the
suspended particulates. Total acidity is a useful measurement in that it is capable
of detecting occurrences of severe acid aerosol pollution. These results do not
show a severe problem. The negative results are caused by the alkaline nature of
the suspended particulates in this area.
Survey of Airborne Pollutants
45
-------
ON
a
tn
w
>
r
Table 2-3. PARTICULATE SULFATE SUMMARY STATISTICS
Station
1
2
3
4
6
Location3
Degrees Miles
34 0.8
105 2.5
112 0.4
274 4.5
2 0.5
Sampling
period
June
through
October
1969
June
through
October
1969
June
through
October
1969
June
through
October
1969
September
through
October
1969
Statistics, /ig/m3
N
76
88
87
84
34
X
3.5
3.7
4.1
2.9
4.5
S
1.4
1.5
1.8
1.6
1.8
\
3.3
3.4
3.7
2.5
4.0
Sq
1.5
1.5
1.7
1.8
1.7
Min
0.9
0.9
0.3
0.3
1.1
PIO
2.0
2.0
2.1
1.1
—
P25
2.5
2.6
3.1
1.7
—
Pso
3.4
3.5
3.9
2.5
—
PTS
4.2
4.3
4.9
3.9
—
Pgo
5.2
5.7
6.6
5.2
—
Max
8.6
9.8
9.6
7.0
7.7
o
2
H
>
r
*TS
O
r
c
H
H- (
O
z
c
a
3Degrees are computed from north side of ASARCO stack in clockwise direction.
-------
Table 2-4. PARTICULATE ACIDITY SUMMARY STATISTICS
Station
1
2
3
4
6
Location3
Degrees Miles
34 0.8
105 2.5
112 0.4
274 4.5
2 0.5
Sampling
period
June
through
October 1969
June
through
October 1969
June
through
October 1969
June
through
October 1969
September
through
October 1969
Statistics, (Ug/m3
N
74
88
87
85
34
X
0.0
-0.7
-0.6
0.0
0.8
S
1.6
1.4
1.6
0.7
0.8
Min
-3.1
-5.3
-7.4
-2.4
-0.3
Max
8.8
1.4
2.0
2.2
2.4
aDegrees are computed from north side of ASARCO stack in clockwise direction.
Nylon deterioration as measured by the Effects Network station3 in East
Helena indicated that a problem of acid aerosols might exist in East Helena. A
network of additional nylon panel exposures was set out to determine the extent
of the problem. Results from the 3-month exposure indicated that the problem
was not sufficiently widespread or serious for further consideration. Only
exposures within 1 mile of East Helena industry were affected.
NONSPECIFIC PARTICULATES
Total Suspended Particulates
Total suspended particulate matter was sampled by means of Electro
Neutronics, Inc., samplers at five locations on a schedule that skipped every
third day. The first four sampling locations were identical to the sampling
locations of the continuous monitors. Sampling station 6 was added late in the
study period to get particulate metal data from a point closer to the middle of
the city of East Helena. The sampler was located in the immediate vicinity of the
East Helena City Hall. Table 2-5 is a summary of the results. The sampling
locations are identified by number, and location is given in miles and degrees
from the smelter stack.
Settleable Particulates
Settleable particulate matter or dustfall was measured at five locations on a
Survey of Airborne Pollutants
47
-------
4*.
oo
a
en
r
r
Ffl
-<
W
1
?B
O
s
en
Z
H
>
r
3
H
HH
O
H
C
O
Table 2-5. TOTAL SUSPENDED PARTICULATE SUMMARY STATISTICS
Station
1
2
3
4
6
Location3
Degrees Miles
34 0.8
105 2.5
112 0.4
274 4.5
2 0.5
Sampling
period
June
through
October
1969
June
through
October
1969
June
through
October
1969
June
through
October
1969
September
through
October
1969
Statistics, jug/m3
N
76
88
87
85
34
X
108
74
59
62
166
\
91
56
47
52
136
Min
14
4
1
1
26
PIO
29
21
17
22
44
P25
63
35
33
40
88
Pso
112
58
56
57
167
P7s
147
112
76
85
232
Pgo
178
148
99
105
276
Max
241
204
181
158
360
aDegrees are computed from north side of ASARCO stack in clockwise direction.
-------
monthly basis using 5-quart Tupperware canisters for samplers. These results are
presented in Table 2-6. The highest dustfall results were measured at the East
Helena City Hall sampling location. This location also had the highest measured
suspended particulates.
Table 2-6. SETTLEABLE PARTICULATE RESULTS
Station
1
2
3
4
6
Location3
Degrees
34
105
112
274
2
Miles
0.8
2.5
0.4
4.5
0.5
g/m2— mo
June
2
2
3
5
8
July
3
2
2
2
8
Aug
3
2
2
3
4
Sept
_
—
_
1
5
Oct
_
—
_
1
4
aDegrees are computed from north side of ASARCO stack in clockwise direction.
Windblown Particulates
Windbown particulates were collected using adhesive impactors (sticky
paper) at 40 locations. This sampling was done in conjunction with the metal-fall
collection. Because of the extended sampling period (1 and 2 months), the
deposition rate results are not valid. Microscopic examination of these particu-
lates, however, is valid and revealed that the particles were predominantly of
natural origin. This indicates that if windblown particulates are a problem in this
area, the principal causes are the semi-arid soil and unpaved streets.
Soiling Index
Soiling index was measured continuously at four locations on a 2-hour cycle
using Unico 80 TS samplers. These results, which are summarized in Table 2-7,
are low and do not warrant further consideration.
Table 2-7. SOILING INDEX SUMMARY STATISTICS,
JULY THROUGH OCTOBER 1969
Station
1
2
3
4
Location3
Degrees Miles
34 0.8
105 2.5
112 0.4
274 4.5
Number
nf
samples
1,831
1,466
1,646
1,686
% of time each station exceeded
indicated Coh/103 lineal feet
0
64
96
100
97
>0.2
24
2
—
^3
>0.5
7
0.3
—
1.6
>1.0
1
-
—
0.5
>1.5
0.2
-
—
0.3
>2.0
0.06
-
-
0.06
aDegrees are computed from north side of ASARCO stack in clockwise direction.
Survey of Airborne Pollutants
49
-------
METALLIC PARTICULATES
Four metals, arsenic, cadmium, lead, and zinc, are considered the most
probable contaminants being emitted from East Helena industry. The suspended
particulates and settleable particulate samples were analyzed for these metals.
Because the glass-fiber filters were expected to distort the metal analyses, special
samples were also taken on membrane filters. These samples were taken on a
72-hour basis in parallel with the standard 24-hour high-volume samples. At
about 40 locations, settleable particulates were collected and analyzed. A 2.25-
inch-diameter plastic container was used to collect these samples. The purpose of
this sampling was to obtain information on the radial distribution of metals
settling upon the ground. Samples were collected during August, September, and
October 1969.
Arsenic
The study findings concerning arsenic are summarized in Table 2-8 and
Figure 2-18.
Table 2-8. PARTICULATE ARSENIC SUMMARY
Station
Location
1
0.8 mi; 34°
2
2.5 mi; 105°
3
0.4 mi; 112°
4
4.5 mi; 274°
6
0.5 mi; 2°
Settleable Particulates
(mg/m2— mo)
June
July
August
September
October
1.7
1.6
0.6
0.0
0.9
0.0
0.2
1.3
0.0
0.0
0.0
9.6
2.2
0.0
2.3
0.0
0.0
1.0
0.0
0.0
—
_
0.2
-
Suspended Particulates on Membrane Filters
(Atg/100m3)
N
X
Maximum
Minimum
28
0.7
2.0
0.0
25
0.6
2.0
0.0
23
8.2
40.0
0.0
8
0.9
1.0
0.0
-
50 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 2-8 (continued). PARTICULATE ARSENIC SUMMARY
Station
Location
N
X
Maximum
Minimum
>0 to <5
>5
>10
>20
1
0.8 mi; 34°
2
2.5 mi; 105°
3
0.4 mi; 112°
4
4.5 mi; 274°
6
0.5 mi; 2°
Suspended Particulates on Glass-Fiber Filters
(;ug/100m3)
76
0.6
7.0
0.0
8
3
0
0
87
1.1
9.0
0.0
14
8
0
0
85
6.0
26.0
0.0
18
40
23
1
82
0.5
7.0
0.0
13
2
0
0
34
8.4
26.0
0.0
8
22
11
1
The settleable particulate deposition rate of arsenic was greater in East
Helena than in Helena. Sampling location 3, which is the closest to the industrial
complex, has the highest values.
Of the samples taken on membrane filters, the highest values were measured
at station 3. Three of the four sampling locations averaged less than 1 microgram
of arsenic per 100 m3. At site 3, the concentrations averaged 8.2, with a
maximum of 40 /ug per 1003 .
The samples collected on glass-fiber filters are in agreement with the
membrane samples. Because of the shorter sampling time, the maximum values
are somewhat higher. Results at sampling locations 3 and 6 show that nearness
to the industrial complex causes higher values. Within a half mile of the stack,
the concentration is elevated; however, beyond 1 mile, the concentration tends
to level out.
Figure 2-18 shows the radial distribution of the rate of arsenic fallout. This
distribution was obtained from the results of the metal-fall samples collected
during September, October, and November.
Survey of Airborne Pollutants
51
-------
ffi
tn
r
w
z
mt Ic
r
w
i
H^
JO
o
z
1
3
r
H
> 1 to < 4
05
H
C
a
Figure 2-18. Settleable particulate arsenic radial distribution.
-------
Cadmium
The findings concerning cadmium are summarized in Table 2-9 and Figure
2-19.
The settleable particulate rate of cadmium deposition decreases with
increasing distance from the East Helena industry. Sampling locations 3 and 6
had the highest values.
The samples on membrane filters and on glass-fiber filters are in general
agreement with one another and with the settleable particulate samples, in that
cadmium concentration increases with decreasing distance from the East Helena
industrial complex. Sampling site 6, East Helena City Hall, had the most
cadmium.
Table 2-9. PARTICULATE CADMIUM SUMMARY
Station
Location
1
0.8 mi; 34°
2
2.5 mi; 105°
3
0.4 mi; 112°
4
4.5 mi; 274°
Q
0.5 mi; 2°
Settleable Particulates
(mg/m2— mo)
June
July
August
September
October
0.0
0.5
0.2
0.5
0.5
0.0
0.1
0.1
0.3
0.4
2.0
3.0
1.6
1.2
1.5
0.1
0.1
0.1
0.2
0.2
-
-
2.2
3.2
Suspended Particulates on Membrane Filters
(Atg/100m3)
N
X
Maximum
Minimum
28
2.3
8
0
25
1.4
4
0
23
6.7
16
0
8
0.6
1
0
—
—
—
-
Suspended Particulates on Glass-Fiber Filters
(Aig/100m3)
N
X
Maximum
Minimum
>0 to <5
>5
>25
>50
76
6.1
20
2
49
27
0
0
87
2.5
12
0
76
6
0
0
85
10.2
46
0
28
56
5
0
82
2.9
11
1
73
9
0
0
34
29.4
69
1
4
30
17
7
Survey of Airborne Pollutants
53
-------
ffi
W
r
w
r
1
S
3
o
r
r
G
o
z
Ln
H
C
O
Figure 2-19- Settleable particulate cadmium radial distribution.
-------
Figure 2-19 shows the spatial distribution of the deposition rate of cadmium
on the area per month during the months of August through October. This
distribution was obtained from the results of the 40 metal-fall samplers.
Measurements indicate that 1 to 4 mg of cadmium per aquare meter of area was
deposited on a 1.5-square-mile area around the East Helena industrial complex;
0.1 to 1 mg of cadmium per square meter of area was deposited over an area of
about 60 square miles around East Helena.
Lead
The findings concerning lead are summarized in Table 2-10 and Figure 2-20.
Table 2-10. PARTICULATE LEAD SUMMARY
Station
Location
1
0.8 mi; 34°
2
2.5 mi; 105°
3
0.4 mi; 112°
4
4.5 mi; 274°
6
0.5 mi; 2°
Settleable Participates
(mg/m2—mo)
June
July
August
September
October
3
19
10
19
40
1
4
3
9
10
54
106
5
63
108
1
4
3
7
7
—
-
27
60
Suspended Particulates on Membrane Filters
(M9/10m3)
N
X
Maximum
Minimum
28
5.8
11
1
25
2.7
8
1
23
9.5
18
1
8
3.8
6
2
—
—
-
Suspended Particulates on Glass-Fiber Filters
Oug/10m3)
N
X
Maximum
Minimum
>0to<10
>10
>50
>100
76
4.5
53
0
69
5
1
0
87
2.4
25
0
78
2
0
0
85
12.5
160
0
55
27
4
1
82
1.0
7
0
54
0
0
0
34
38.8
150
2
9
25
10
4
Survey of Airborne Pollutants
55
-------
ffi
w
i
m
z
w
z
H
>
r
3
r
r
on
G
Figure 2-20. Settleable particulate lead radial distribution.
-------
The settleable particulate deposition rate of lead increases dramatically in
the proximity of the East Helena industrial complex. At station 3, as much as
625 pounds of lead per square mile was deposited during the month of October.
During the same month, 350 pounds of lead per square mile was deposited in the
vicinity of East Helena City Hall. In Helena, 40 pounds of lead per square mile
was deposited during the same month.
The suspended particulate samples, collected on glass-fiber filters and on
membrane filters, and the settleable particulate samples are in agreement in that
the lead content increases with decreasing distance from the East Helena
industrial complex. At station 3 the lead concentration averaged about 1
microgram per cubic meter. At station 6, East Helena City Hall, the suspended
particulates averaged about 4 micrograms of lead per cubic meter, with values
ranging up to 15. The concentration in Helena averaged 0.1, with individual
values ranging up to 0.7 microgram of lead per cubic meter. The people in East
Helena (stations 1 and 6) are exposed to between 0.5 and 4 micrograms per
cubic meter, with individual daily doses up to 15 micrograms per cubic meter.
Figure 2-20 shows the radial distribution of the deposition rate of lead. This
distribution was obtained from the results of the metal-fall samples. Measure-
ments indicate that 30 to 140 milligrams of lead per square meter per month is
deposited on about 2 square miles of area around East Helena; 10 to 30
milligrams of lead per square meter per month is deposited on about 8 square
miles of area around East Helena.
Zinc
The findings concerning zinc are summarized in Table 2-11 and Figure 2-21.
The settleable particulate deposition rate of zinc increases dramatically in
the proximity of the East Helena industrial complex. The highest values were
obtained at the East Helena City Hall sampling site (station 6). This sampling
location is the nearest to the Anaconda Company and American Chemet, both
of which process zinc oxide.
The total suspended particulate samples collected on glass-fiber filters and
on membrane filters agree reasonably well. Because of the zinc content of the
glass-fiber filters, it was possible to measure zinc only to the nearest microgram
per cubic meter. Zinc content was measured to the nearest tenth of a microgram
per cubic meter on the membrane filter samples. The East Helena City Hall
sampling site had the highest values; the average was about 3 micrograms per
cubic meter, with daily values ranging up to 8 micrograms per cubic meter.
Figure 2-21 shows the spatial distribution of the deposition rate of zinc on
the area. This distribution was obtained from the results of the metal-fall
samples. Measurements indicate that 30 to 90 milligrams of zinc per square
meter per month are deposited on about 1.5 square miles of area around East
Helena; 10 to 30 milligrams of zinc per square meter per month are deposited on
about 8 square miles of area around East Helena. The figure also shows other
Survey of Airborne Pollutants 57
-------
areas with such a rate of deposition; however, these areas are defined by single
samples and should not be considered significant. The deposition rate in the
remaining Helena Valley (about 60 square miles) could be considered to average
nearly 5 milligrams of zinc per square meter per month.
Table 2-11. PARTICULATE ZINC SUMMARY
Station
Location
1
0.8 mi; 34°
2
2.5 mi; 34°
3
0.4 mi; 112°
4
4.5 mi; 274°
6
0.5 mi; 2°
Settleable Particulates
(mg/m2— mo)
June
July
August
September
October
5
13
7
12
6
3
4
2
1
3
29
29
26
13
7
9
5
2
5
2
_
—
—
88
71
Suspended Particulates on Membrane Filters
N
X
Maximum
Minimum
28
6.4
14
2
25
2.5
5
1
23
7.6
21
1
8
1.8
3
1
_
_
-
Suspended Particulates on Glass-Fiber Filters
N
X
Maximum
Minimum
>0 to <2
>2
>5
76
0.3
3
0
18
1
0
87
0.1
1
0
4
0
0
83
0.6
4
0
27
5
0
82
0.0
1
0
1
0
0
34
3.3
8
0
7
13
7
OZONE AND NITROGEN DIOXIDE
Limited ozone and nitrogen dioxide measurements were made in con-
junction with the vegetation effects studies.
Ozone
A Mast Ozone Meter ran continuously at sampling location 1 (East Helena-
58 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
n
o
i-b
>
o
n
VSTACI/;:;-'
mg/m -mo
|:-':| > 10 to < 30
> 30 to < 90
Figure 2-21. Settleable particulate zinc radial distribution.
-------
Prickly Pear Street) from June 14 to September 9, and at sampling location 3
(Vollmer's Ranch) from September 9 to September 22. The instrument indi-
cated that the concentration of ozone varied at both sampling locations between
0.03 and 0.04 ppm. The instrument recorded 0 ppm during the episode
fumigations by sulfur dioxide.
Nitrogen Dioxide
A Beckman portable nitrogen dioxide analyzer, Model K1008, ran con-
tinuously at sampling location 3 (Vollmer's Ranch) from October 5 to October
12, 1969. During that time the instrument failed to detect nitrogen dioxide. The
sensitivity of the instrument as used was estimated to be 0.01 ppm.
REFERENCES FOR CHAPTER 2
1. Huey, N. A. The Lead Dioxide Estimation of Sulfur Dioxide
Pollution. JAPCA,7#(9):610-611, September 1968.
2. Huey, N. A., M. A. Waller, and Charles Robson. Field Evaluation of
an Improved Sulfation Measurement System. Paper No. 69-133;
presented at 62nd Annual Meeting of the Air Pollution Control
Association, June 22-26,1969.
3. Cavender, James et al. Interstate Surveillance Project: Measurement
of Air Pollution Using Static Monitors. U.S. Environmental Protec-
tion Agency, Office of Air Programs. Publication No. APTD-0666.
Research Triangle Park, N.C. 27711. 1971.
60 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
3. SURVEY OF WATER QUALITY
Albert V Soukup
ENVIRONMENTAL PROTECTION AGENCY
Office of Water Programs
INTRODUCTION
As part of the Helena Valley Area Environmental Pollution Study, the
Bureau of Water Hygiene, Public Health Service, Region VIII, was requested to
ascertain the chemical constituents of all drinking and irrigation waters in the
area, analyze the data, and prepare a report.
TYPES OF WATER SUPPLIES
In the Valley both surface and ground waters are used by the public. The
city of Helena obtains some of its water from a surface supply located northeast
of East Helena. This water receives conventional treatment that includes
filtration at a water plant located north of East Helena. The remaining water
supply is obtained from an area near the west end of the city, which should not
be influenced by air pollution in the Valley. East Helena obtains its water from a
well field located north of the city and from a surface supply 2.5 miles
south-southeast of the city, McClellan Creek. Chlorination of the waters is the
only treatment provided.
SAMPLING
Water samples were collected on July 1, 1969, October 25, 1969, and April
4, 1970. On July 1, samples were collected from six locations. These samples are
considered typical of the area's water supply, and they served as screening
portions. The locations were selected after taking into consideration the
topography and prevailing wind directions. The samples collected on October
25, 1969, were meant to be from the same locations; however, because of
adverse climatic conditions, samples could not be obtained at two of the sites
representative of the East Helena city water supply. Accordingly, East Helena
city tap water was sampled. On April 4, 1970, three water samples were taken.
These samples were from the two different city water sources and from Prickly
Pear Creek.
61
-------
Sampling Locations
1. Residence of Ray Gustafson, ground-water sample from a 32-foot
well. Location SE1/4, Sec 28 T9N, R2W (about 6 miles SSE of
East Helena).
2. McClellan Creek, surface water, upstream of the East Helena
intake, SE1/4, Sec 32 T9N, R2W (about 6 miles south of East
Helena).
3. Helena Water Plant intake, surface water, NE1/4, Sec 17, T10N,
R2W (about 3 miles NE of East Helena).
4. East Helena city well supply, NE1/4, Sec 23, T10N, R3W (about
1.5 miles NW of East Helena).
5. East Helena Surface Water Reservoir, McClellan Creek supply,
NW1/4, Sec 17, T9N, (about 2.5 miles SSE of East Helena).
6. Prickly Pear Creek, surface water, SE1/4, Sec 15, T10N, R3W
(about 2.5 miles NW of East Helena).
7. East Helena city tap, center of town.
LABORATORY METHODS
The 1-gallon samples of water from each sampling location were air-mailed
to the Cincinnati, Ohio, laboratory of the Public Health Service. The analytical
methods used were those specified in Standard Methods for the Examination of
Water and Wastewater, American Public Health Association, current edition, and
other approved methods in a few instances.
RESULTS
All samples were analyzed for the following: arsenic, cadmium, lead, zinc,
iron, manganese, sulfate, fluoride, chromium, silver, copper, cobalt, nickel,
chloride, nitrate, boron, cyanide, selenium, pH, specific conductance, turbidity,
color, and total dissolved solids. Analyses of the first seven components were
found to give pertinent information to the study. These results are reported in
Table 3-1.
DISCUSSION OF RESULTS
Samples from sampling locations 1 and 2 can be considered control samples
since they are the most distant from the East Helena smelting complex. It should
be noted, however, that these two sampling locations are downwind and may,
therefore, be influenced by airborne pollutants. Sampling location 3 is related to
the Helena city water supply. Since samples from location 6 are from Prickly
Pear Creek, these may be expected to be influenced by water runoff from the
62 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 3-1. WATER QUALITY ANALYTICAL RESULTS
(mg/1)
Sampling
location
1
2
3
4
5
6
7
Sampling
date
7/1/69
10/25/69
7/1/69
10/25/69
7/1/69
10/25/69
4/4/70
7/1/69
7/1/69
7/1/69
10/25/69
4/4/70
10/25/69
4/4/70
Recommended DWSa
Mandatory
limits of DWS
As
0
<0.007
0
<0.007
0
0.020
0.017
0
0
<0.030
0.007
0.014
0.007
<0.01
0.010
0.050
Cd
0.002
0
0
0
0
0
0.003
0
0
0.006
0.001
0.007
0
0
-
0.010
Pb
0.027
0
0.010
0
0.033
0
0.019
0.010
0
0.044
0
0.042
0
0.012
-
0.050
Zn
0.092
0.012
0.004
0.016
0.003
0.007
0.032
0.012
0.164
0.056
0.070
0.025
0.016
5.000
-
Fe
0.080
0.018
0.152
0.012
0.146
0.037
0.023
0.015
0.153
0.800
0.036
0.320
0.023
0.016
0.300
-
Mn
0.013
0.004
0.018
0
0.025
0.007
0.013
0
0.009
0.160
0.007
0.051
0.002
0.050
-
S04
29
31
15
17
41
33
32
54
17
30
52
52
21
26
250
-
aDWS= drinking water standards.
smelter complex and from the large slag piles. Sampling locations 4, 5, and 7 are
related to the East Helena city water supply.
The chemical constituents determined did not exceed the mandatory limits
of the Public Health Service Drinking Water Standards. The sulfate results show
that there is no contamination by sulfur dioxide. The water in Prickly Pear
Creek contains elevated levels of arsenic, cadmium, lead, zinc, iron, and
manganese. The water at the Helena city water intake has elevated levels of
arsenic, lead, and manganese.
SUMMARY
The smelting complex in East Helena is contributing measurable amounts of
arsenic, cadmium, lead, zinc, iron, and manganese to the surface water in the
Helena Valley. These amounts do not exceed the mandatory limits of the Public
Health Drinking Water Standards. On the basis of these investigations, the water
quality appears to be satisfactory from a public health standpoint. No bacterio-
logical or radiochemical analyses were made.
Survey of Water Quality
63
-------
4. ABUNDANCE AND DISTRIBUTION OF LEAD,
ZINC, CADMIUM, AND ARSENIC IN SOILS
A. T. Miesch and Claude Huffman, Jr.
DEPARTMENT OF INTERIOR
U.S. Geological Survey
INTRODUCTION
An investigation of the abundance and distribution of lead, zinc, cadmium,
and arsenic in soils of the Helena Valley area of Montana was undertaken. The
purpose of the investigation was to determine the extent of contamination of
the soils by emissions from the smelter operation in East Helena.
CHARACTER OF SOILS
The soils of the Helena Valley are developed largely on valley fill derived
from surrounding mountain ranges, and on lake sediments of Tertiary age. They
are composed predominantly of silt and clay, are moderately calcareous, and
have only small organic contents. The soils formed on valley fill contain
abundant rock fragments, and soil profiles are only poorly to moderately
developed. The rock fragments are extremely diverse in type, reflecting the
diverse geology of the mountains nearby. None of the rock fragments are of a
type containing unusual amounts of lead, zinc, cadmium, or arsenic. In areas
where the soil has been cultivated, most of the rock fragments have been
removed.
Soil profiles on the lake sediments of Tertiary age are also poorly to
moderately developed. The lake sediments in the Canyon Ferry Lake area,
immediately east of the Helena Valley, have been described by Mertie, Fischer,
and Hobbs.1 Most of the sediments are rich in tuffaceous materials of volcanic
origin. The lake sediments in the study area are confined largely to the
southeastern part of the Helena Valley.2
SAMPLING
Soil samples are collected at a confined spot, but are intended to represent
the soils of the vicinity. If the soils in the vicinity are uniform in composition,
little or no sampling error is expected. If, however, the soils in the vicinity are
highly variable in composition, as is commonly the case, large sampling errors
can result. A sampling locality, or site, was formally defined in this study as a
65
-------
circular area 100 feet in diameter; samples were taken within localities using
randomization procedures. Duplicate samples were taken to measure variability
within localities and, therefore, the magnitude of sampling error. Duplicate
chemical analyses were made of randomly selected samples to determine the
analytical precision or the magnitude of laboratory error.
In view of the fact that the purpose of this study was to assess the
magnitude of lead, zinc, cadmium, and arsenic contamination from the smelter
operation in East Helena, as reflected in the soils, the sampling localities were
placed strategically for this purpose.
Eight sampling sites were placed along a straight line (traverse A) extending
east-southeast from the main smelter stack in East Helena. The first site was at a
distance of 0.67 mile from the stack; subsequent sites were placed at geomet-
rically increasing distances of 1, 1.5, 2.25, 3.37, 5.062, 7.5, and 11 miles as
shown in Figure 4-1 (each distance is approximately 1.5 times greater than the
previous one). All of the sampling localities were within cultivated fields.
Seven other sampling sites were placed along a straight line (traverse B)
extending approximately north-northeast from the smelter stack, spaced at
distances of from 0.67 to 7.5 miles from the stack, as was done along traverse A.
The sites were all within cultivated fields.
Ten additional sampling sites were placed along a line (traverse C) extending
generally northwest from the stack. These also were spaced at geometrically
increasing distances from the stack, as in traverses A and B. The site nearest the
stack was at a distance of 0.67 mile; the most distant site, C9, was 25 miles from
the stack. The eight sites nearest the stack were within cultivated fields, whereas
sites C8 and C9 were in areas that may never have been under cultivation.
Four sampling sites were placed along an irrigation ditch (traverse D) that
extends generally northeastward from East Helena in the vicinity of traverse B.
All samples from these localities were taken near the ditch, in places unlikely to
have been cultivated or fertilized for some years. The ditch has been there for at
least 20 years since it is represented on a topographic map of the East Helena
quadrangle published by the U.S. Geological Survey in 1950. The sites are
spaced at distances of 1, 1.5, 2.25, and 3.375 miles from the smelter stack.
Two sampling sites, E and F (Figure 4-1), were placed at a distance of 4.5
miles from the stack; site E was between traverses A and B, and site F was
between traverses B and C.
Six sampling sites were placed in areas remote from East Helena, outside of
the Helena Valley. Two of these, Rl and R2, were west of the Continental
Divide, about lOmiles north of the town of Avon. Two others, R3 and R4, were
east of Canyon Ferry Lake, about 8 miles northeast of Townsend. The other
two, R5 and R6, were on the north side of Rattlesnake Mountain and about 20
miles north of Helena. The soils in the Canyon Ferry Lake area developed on
lake sediments of Tertiary age, similar to those in the Helena Valley. The soils
north of Avon and those north of Rattlesnake Mountain are developed on valley
66 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
so
CL
N
n
O
65
Cu
5'
63
I
R-
C/3
O
%
I C9 |25 MILES TO STACK)
C8 (16 MILES TO STACK)
R6
••R5
(21 MILES TO STACK)
• Rl
•R2
(37 MILES TO STACK)
01234
MILES
NOTE: POINTS R 1. R 2. R 3. R 4, R 5. R 6, C 8, AND C 9 ARE NOT TO SCALE.
(25 MILES TO STACK)
R4*
R3»
Os
Figure 4-1. Sampling locations.
-------
fill. All samples collected outside the Helena Valley were from uncultivated
fields.
A single site, M, was located in a cultivated field about 1000 feet southwest
of the smelter stack.
The sampling procedure at each of the sites referred to above (except those
along traverse D) was as follows: by use of rectangular coordinates and a table of
random numbers, two random points were located within each site—the site, as
mentioned previously, was defined as a circular area 100 feet in diameter. At
each point, one sample was taken from the upper 4 inches of soil (within the
plow zone in cultivated areas) and another was taken at a depth of 6 to 10
inches (generally below the plow zone). Thus, four samples were taken from
each site. The samples were taken with a small spade, and care was taken to
avoid soil that had touched the spade itself. Each sample consisted of about 100
grams and was stored in a paper envelope until received in the laboratory.
Samples collected along the irrigation ditch in traverse D were taken from
depths of from 0 to 1 inch, 2 to 4 inches, and 6 to 10 inches.
A number of other samples and sample sets were taken for special purposes.
Among these was a set of five soil samples collected at site HI, immediately
north of U.S. Highway 12 and about 2 miles west of East Helena; this set was for
use in a search for significant highway contamination effects. The samples were
collected at distances of 5, 10, 20, 40, and 80 feet from the pavement. Another
set of five soil samples was collected at site H2, about 1000 feet north of site HI
and on the north side of the tracks of the Northern Pacific Railroad. The
samples were collected at distances of 5, 10, 20, 40, and 80 feet from the tracks.
The three samples taken from nearest the tracks were of fill material that forms
the track bed. All samples in the series HI and H2 were collected from the upper
1-inch layer.
Two additional samples were taken of the upper 4-inch soil layer at site N,
and samples of siltstone of the Belt Series of Precambrian age and of tuffaceous
sediments of Tertiary age were collected at sites 0 and P, respectively.
LABORATORY METHODS
A total of 176 samples was collected in this study. Twenty-one of these,
selected at random, were homogenized and split once in a Jones splitter
constructed of aluminum, yielding 197 samples for laboratory analysis. The 197
samples were assigned new sample numbers and analyzed in randomized
sequence; neither the locations from which the samples were taken nor the
duplicate splits were known to the analyst.
Sample preparation prior to laboratory analysis consisted of passing the
samples through a jaw crusher to reduce rock fragments present in some of them
and grinding through ceramic plates set to -100 mesh.
Lead and zinc contents were determined by an atomic absorption technique
68 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
developed by Huffman and J.A. Thomas.3 A 1-gram sample is placed in a
150-ml beaker and moistened with about 10 ml of water. Ten ml of HN03 is
added, and the beaker is covered with a watch glass. The solution is then boiled
on a shaking hotplate until the volume is reduced to about 7 ml. It is then
cooled and the sides of the beaker are washed down with about 25 ml of water.
The beaker is covered with a watch glass again and placed on a steam bath for 30
minutes. The solution is then cooled, transferred to a 50-ml volumetric flask,
diluted to volume, and mixed. The flask is then allowed to stand for several
hours to permit the insoluble residue to settle. A portion of this solution is then
atomized into the flame of the atomic absorption instrument for the deter-
mination of lead. Ten ml of this solution (1 gram in 50 ml) is diluted to 50 ml
volume for the zinc determination. A few of the samples, high in lead or zinc,
required additional dilutions. Table 4-1 gives the instrumental parameters used.
Table 4-1. INSTRUMENTAL PARAMETERS FOR DETERMINING
LEAD AND ZINC CONTENT OF SOIL
Parameters
Instrument
Wavelength
Sou rce
Burner
Flame
Flame condition
Slit
Scale
Lead
P E model 303
2836 A
Hollow cathode
Laminar
Air-acetylene
Oxidizing
4
X-5 or X-1
Zinc
P E model 303
2138 A
Hollow cathode
Laminar
Air-acetylene
Oxidizing
4
X-2orX-1
The 2836 A wavelength line was selected for the determination of lead
because calcium interfered at the more sensitive 2170 A line. Little or no
interference was noted at the 2836 A line.
Cadmium was determined by an atomic absorption method, described by
Nakagawa and Harms,4 after some modification in the sample digestion
procedure. One-gram samples were boiled in 5 ml of HN03 and then diluted to
20 ml, rather than 10 ml, to reduce the possibility of calcium interference.
Ten samples, selected randomly from the total 197, were digested in HF
(and HN03 and HCL04) using a procedure described by Huffman5 and
reanalyzed for lead, zinc, and cadmium by atomic absorption procedures. The
HF digestion is more complete than that achieved using boiling HN03, but the
differences were judged insignificant for the purposes of this investigation. The
lead, zinc, and cadmium not extracted by boiling HNO3 are possibly contained
in stable silicate and oxide minerals that commonly occur as natural soil
components.
Arsenic was determined by a modified Gutzeit method described by Ward et
al.6 This method, specifically for determining arsenic in soils, is a confined-spot
procedure using a modified Gutzeit apparatus in which, by the action of zinc in
Lead, Zinc, Cadmium, and Arsenic in Soils
69
-------
hydrochloric acid solution, arsenic III is reduced to arsine (AsH3) gas, which
reacts with mercuric chloride to form a yellow-to-orange compound. Artificial
standards, corresponding to known arsenic concentrations, are used to estimate
the concentrations of arsenic in the unknowns. Rather than digestion of the
sample after fusion with potassium hydroxide,6 digestion was accomplished by
boiling first in HN03 and then in HC1. The arsenic in the sample, therefore, was
oxidized by HNO3, and excess HNO3 was destroyed by boiling in HC1 before
adding the zinc.
Evaluation of Errors Due to Sampling and Laboratory Analysis
Two sources of error are regarded as important in this investigation. One of
these is the variability of soils within sampling localities. Because of this
variability, individual samples or pairs of samples do not represent precisely the
localities from which they were taken - that is, no single sample has the
composition of the sampling locality as a whole, and neither does the average of
any sample pair. A second source of error is the variability in laboratory analysis;
the same sample subjected to repeated analysis yields a spread of analytical
values. No single analysis or no average analysis can be expected to correspond
exactly to the true concentration of the element in the sample analyzed.
Estimates of the total experimental error, due to both sampling and
laboratory analysis, were obtained for each element by comparing the analytical
results on duplicate samples from 33 sampling sites. Within each locality, one
duplicate pair was obtained from the upper 4 inches of soil, and one was
obtained from the depth of 6 to 10 inches, yielding a total of 66 pairs. Pairs
were not used in the error estimates, however, if the element was not detected in
one or both samples of the pair. Thus, 41 pairs were used in the estimate of total
experimental error in lead, 66 pairs were used for zinc, 62 pairs were used for
cadmium, and 40 pairs were used for arsenic. The estimates of total experi-
mental error for each element, expressed as logarithmic variance and as
geometric error, are listed in Table 4-2. The geometric error, which is the
antilogarithm of the square root of the log variance, may be used to determine
the expected range for the correct value for a sampling locality from an
individual analysis. The expected range, with a confidence of 68 percent, is from
the analytical value divided by the geometric error to the analytical value times
the geometric error. For example, if the analytical value for lead is 100 parts per
million, the correct value for the sampling locality is expected to be in the range
67 (=100/1.49) to 149 (=100x1.49) parts per million.
Table 4-2. ESTIMATES OF EXPERIMENTAL ERROR
Element
Lead
Zinc
Cadmium
Arsenic
Log variance
0 0303
0 0039
0 0223
0 0230
Geometric error
1 49
1 16
i 41
1 4?
70 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
The relative importances of the two sources of error, sampling and
laboratory analysis, have been estimated using the duplicate analyses of the 21
randomly selected samples referred to previously. These estimates, again ex-
pressed as logarithmic variances, are given in Table 4-3. Thus, sampling and
laboratory analysis are estimated to be about equally important sources of error
in the data on arsenic, but sampling is the dominant source of error in the data
on lead, zinc, and cadmium. More precise laboratory methods would not
significantly improve the quality of the data.
Table 4-3. ESTIMATED RELATIVE IMPORTANCE OF ERRORS
IN SAMPLING AND LABORATORY ANALYSIS
Source of error
Sampling
Laboratory analysis
Total error
Lead
0.0247 (82%)
0.0056 (18%)
0.0303
Zinc
0.0028 (71%)
0.001 1 (29%)
0.0039
Cadmium
0.0147 (66%)
0.0076 (34%)
0.0223
Arsenic
0.0098 (43%)
0.0132 (57%)
0.0230
Since two samples were collected from each depth zone in each locality,
each depth zone in each locality can be represented by an average of two values.
The error variances of the averages representing each locality are one-half those
given above, but the relative importances of the sources of error are the same.
The sampling error could be reduced to any desired level in future studies of this
kind by collecting a larger number of samples in each locality.
DISCUSSION OF RESULTS
Graphs showing the metal contents of soils, in parts per million, as a
function of distance of the sampling localities from the smelter stack, in miles,
are nonlinear on arithmetic scales, and individual data points exhibit large
amounts of scatter about the curved regression lines. The large scatter results in
part from the proportionate nature of the error in the analytical data; the
expected error in an analysis is approximately proportional to the amount of the
element present in the sample.
These difficulties are partially resolved by plotting the logarithm of the
analytical determination against the logarithm of the distance of the sampling
locality from the smelter stack. Lead, zinc, cadmium, and arsenic contents of the
soils decrease systematically with distance from the smelter stack. The sys-
tematic decrease is generally linear on the log-log scales, and the scatter of points
about the regression lines is homogeneous — that is, independent of the
magnitude of the analytical values. In some cases, the linearity of the relation-
ships and the goodness of fit are remarkable. Results are presented in Table 4-4.
Coefficients of determination (squares of the coefficients of correlation between
log metal content and log distance from the stack) range up to 0.99, indicating
that up to 99 percent of the variance in metal content is statistically associated
with distance from the smelter stack.
Lead, Zinc, Cadmium, and Arsenic in Soils
71
-------
Table 4-4. SOIL METAL CONTENT AS FUNCTION
OF DISTANCE FROM SMELTER
Traverse
A
A
B
B
C
C
D
D
D
A
A
B
B
C
C
D
D
D
A
A
B
B
C
C
D
D
D
A
A
B
B
C
C
D
D
D
Depth, in.
0 to 4
6 to 10
0 to 4
6 to 10
Oto 4
6 to 10
Oto 1
2 to 4
6 to 10
Oto 4
6 to 10
Oto 4
6 to 10
Oto 4
6 to 10
Oto 1
2 to 4
6 to 10
Oto 4
6 to 10
Oto 4
6 to 10
Oto 4
6 to 10
Oto 1
2 to 4
6 to 10
Oto 4
6 to 10
Oto 4
6 to 10
Oto 4
6 to 10
Oto 1
2 to 4
6 to 10
Regression equation
log Pb = 2.91 15 - 1 .4466 log D
log Pb = 2.2962- 1.0910 log D
log Pb = 2.8520 - 1.5244 log D
log Pb = 1.5370 - 0.6251 log D
log Pb = 2.6831 - 1.2952 log D
logPb= 1.6890-0.4561 log D
log Pb = 3.6058 - 2.6996 log D
log Pb = 2.6897 -2. 1421 log D
log Pb = 1 .8679 - 0.0592 log D
log Zn = 2.3109 - 0.5878 log D
log Zn = 2.0294 - 0.3045 log D
log Zn = 2.3854 - 0.8923 log D
logZn= 1.9545 -0.4010 log D
log Zn = 2.6520 -0.8183 log D
logZn = 1.9505-0.1441 log D
log Zn = 3.0525 -2.2717 log D
log Zn = 3.0021 - 2.5064 log D
log Zn = 2.3325- 1.3452 log D
logCd= 1.4226- 1.3571 log D
log Cd = 0.7470 - 0.8342 log D
logCd= 1.3547- 1.4541 log D
log Cd = 0.1 951 - 0.4069 log D
logCd= 1.1322- 1.0770 log D
log Cd = 0.2717 -0.4362 log D
logCd= 1.8347 -2.0268 log D
logCd= 1. 4839 -2. 1642 log D
log Cd = 0.4257 - 0.6867 log D
log As = 1 .7133 - 0.721 1 log D
log As = 1.4920 - 0.6656 log D
log As = 1 .6788 - 1 .0270 log D
log As = 0.9773 - 0.3459 log D
log As = 1.3910 - 0.6162 log D
log As = 1.1169 -0.3145 log D
log As = 2.1605 - 2.6582 log D
log As = 1 .7249 - 2.1320 log D
log As = 1.1 244 - 0.6483 log D
Coefficient of
determination
0.987
0.713
0.908
0.253
0.819
0.361
0.900
0.404
0.104
0.901
0.622
0.935
0.655
0.607
0.167
0.899
0.804
0.498
0.994
0.688
0.973
0.368
0.752
0.450
0.871
0.765
0.120
0.674
0.675
0.636
0.120
0.368
0.176
0.681
0.586
0.143
The expected metal contents of soils at varying distances from the stack, as
determined from the regression equations, are summarized in Tables 4-5 and 4-6.
HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 4-5. EXPECTED LEAD, ZINC, CADMIUM,
AND ARSENIC CONTENTS OF CULTIVATED SOILS
ALONG TRAVERSES A, B, AND C
Traverse
Direction from
smelter stack
Concentration (ppm) at indicated
distance from stack, mi
1
2
4
8
Lead in upper 4-inch soil layer
A
B
C
ESE
NNE
NW
820
710
480
300
250
200
110
86
80
40
30
32
Lead in soils at depth of 6 to 10 inches
A
B
C
ESE
NNE
NW
200
34
49
93
22
36
44
14
26
20
9
19
Zinc in upper 4-inch soil layer
A
B
C
ESE
NNE
NW
210
240
450
140
130
250
91
70
140
60
38
82
Zinc in soils at depth of 6 to 10 inches
A
B
C
ESE
NNE
NW
110
90
89
Cadmium in upper 4-inch
A
B
C
ESE
NNE
NW
26
22
14
87
68
81
70
52
73
57
39
66
soil layer
13
8
6
4
3
3
2
1
1
Cadmium in soils at depth of 6 to 10 inches
A
B
C
ESE
NNE
NW
6
2
2
3
1
1
2
1
1
1
0.7
0.8
Arsenic in upper 4-inch soil layer
A
B
C
ESE
NNE
NW
52
48
25
Arsenic in soils at depth of 6
A
B
C
ESE
NNE
NW
31
9
13
31
23
16
to 10 inches
20
7
10
19
11
10
12
6
7
12
6
9
8
5
7
Lead, Zinc, Cadmium, and Arsenic in Soils
73
-------
Table 4-6. EXPECTED LEAD, ZINC, CADMIUM,
AND ARSENIC CONTENTS OF UNCULTIVATED SOILS
ALONG TRAVERSE D
Element
Lead
Zinc
Cadmium
Arsenic
Depth of soil, in.
Oto 1
2 to 4
6 to 10
Oto 1
2 to 4
6 to 10
Oto 1
2 to 4
6 to 10
Oto 1
2 to 4
6 to 10
Concentration (ppm) at indicated
distance from stack, mi
1
4000
490
74
1100
1000
210
68
30
3
140
53
13
2
620
110
71
230
177
85
17
7
2
23
12
9
4
96
25
68
48
31
33
4
2
1
4
3
5
Lead
The geometric mean concentration of lead in soils of the United States is
given by Shacklette, Hamilton, Boerngen, and Bowles as 16 ppm;7 the geometric
deviation is 1.96. Thus, 95 percent of the soils of the United States are estimated
to have lead contents in the range from 4 (16/1.962) to 61 (16 x 1.962) ppm.
The geometric mean lead content of surface soils collected in this investigation
in areas remote from the Helena Valley is 15 ppm, close to the average for soils
of the United States. The geometric mean lead content of soils collected at a
depth of 6 to 10 inches in the remote areas is slightly lower, 9 ppm.
The frequency distributions of lead are censored at 20 ppm. The mean
logarithms were estimated using a technique described by Cohen8 and Miesch.9
Soils distant from the smelter in East Helena, but of the same type as those
near the smelter, therefore, are not at all extraordinary in the amounts of lead
they contain.
Samples of soil collected from the upper 4-inch soil layer within a mile of
the smelter stack commonly contain more than 1000 ppm lead, and 500 to 800
ppm appears to be about the average at a distance of 1 mile. One sample
collected from the upper 1 inch of the soil layer along the irrigation ditch north
of East Helena contained 6500 ppm lead. Two other samples collected 0.67 mile
northwest of the stack contained 4500 and 6800 ppm lead.
The lead content of the upper 4-inch soil layer decreases progressively away
from the stack for a distance of 10 to 15 miles. Beyond that distance, the lead
content of the upper 4-inch soil layer is about the same as that of soils outside
74 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
the Helena Valley. Both the lead content of the upper 4-inch soil layer and the
correlation of lead content with distance from the stack appear to be related to
wind direction frequency as reported by the Montana State Department of
Health. A wind direction toward the ESE, the direction of traverse A from the
stack, is 5 to 7 times more frequent than toward the NNE or NW, the directions
of traverses B and C. Accordingly, the soils along traverse A are moderately
higher in lead content than those along traverses B and C, and the lead content
displays better correlation with distance from the stack.
Most of the soil samples collected along traverses A, B, and C at a depth of 6
to 10 inches contain lead in amounts greater than generally found in similar soils
outside the Helena Valley, but the amounts are much lower than those found in
the upper 4 inches of soil. Nearly all of the samples taken in the 6- to 10-inch
depth zone were taken below the existing plow layer. Some lead may have been
introduced into this zone by physical mixing caused by deeper plowing in
previous seasons, but most of it has probably moved downward by chemical
leaching processes. The general chemical immobility of lead in soils is reflected
by the fact that the upper 4-inch layer in the vicinity of the smelter tends to
contain about 10 times more lead than the soil at a depth of 6 to 10 inches.
The upper 1 inch of soil at four sampling localities along the irrigation ditch
(traverse D), where the soils have probably not been cultivated for 20 years or
more, tends to contain more lead than cultivated surface soils along traverses A,
B, and C. This is due to the absence of homogenization that occurs with
plowing. The lead present at depth in the uncultivated soils probably results
largely from chemical leaching of lead at the surface and redeposition below.
Samples collected near the highway 2 miles west of East Helena (sampling
site HI, Figure 4-1) contain about the same amounts of lead as other surface
samples from areas the same distance from the smelter stack. Samples collected
near the tracks of the Northern Pacific Railroad (sampling site H2), however,
contain up to almost 5000 ppm lead. The lead here has probably been derived
from railroad cars transporting ore and ore concentrates to and from the smelter,
or from the fill materials that form the railroad bed.
Zinc
The geometric mean zinc content of soils of the United States is given by
Shacklette, Hamilton, Boerngen, and Bowles7 as 44 ppm, with a geometric
deviation of 1.86. Approximately 95 percent of the soils of the United States,
therefore, have zinc contents in the range of 13 (44/1.862) to 152 (44 x 1.862)
ppm. Soil samples collected in this investigation from the upper 4-inch soil layer
in areas outside the Helena Valley have a geometric mean zinc content of 58
ppm; the geometric mean zinc content of those from a depth of 6 to 10 inches is
only slightly less, 50 ppm. Soils in the vicinity of the Helena Valley, but of the
same general type as those found around East Helena, therefore do not contain
unusually high amounts of zinc.
The highest amounts of zinc in the soils of the Helena Valley were found
Lead, Zinc, Cadmium, and Arsenic in Soils 75
-------
within a mile of the smelter stack and along the tracks of the Northern Pacific
Railroad. Nearly all soil samples collected from the upper 4-inch layer within a
mile of the smelter stack contained 200 ppm or more zinc—more than 4 times as
much zinc as that in similar soils outside the Helena Valley. Extraordinarily high
zinc contents of soils (up to 5000 ppm) along the tracks of the Northern Pacific
Railroad 2 miles west of East Helena are too high to have resulted from smelter
stack emissions; the zinc is thought to have been derived either from railroad
cars transporting ores and ore concentrates to and from the smelter, or from fill
materials of which the track bed is formed.
The zinc content of the upper 4-inch soil layer tends to decrease system-
atically away from the smelter stack along traverses A, B, and C for a distance of
10 to 15 miles. The rate of decrease is less than that for lead because the zinc
contents of soils near the smelter stack tend to be only about 4 times higher
than normal.
The zinc contents of soils collected at a depth of 6 to 10 inches along
traverses A, B, and C within a radius of several miles from the smelter stack tend
to be about one-half those of samples collected from the upper 4-inch soil layer
in the same area. This contrasts with the lead contents of the soils at depth,
which tend to be about one-tenth of those of the soils at the surface, and reflects
the greater chemical mobility of zinc in soil profiles. Canney,10 for example,
found in a study of soil contamination near a smelter in Idaho that the zinc
contents of soils were similar in depth intervals of 0 to 2 inches and 2 to 6
inches, whereas the lead contents of soils from the lesser depth zone were
considerably higher. The mobility of zinc in soils has been widely recognized in
geochemical exploration.1'
The greater chemical mobility of zinc is also indicated in the uncultivated
soil samples collected along the irrigation ditch north of East Helena (traverse
D). There the zinc in samples collected at a depth of 2 to 4 inches tends to be
nearly the same as that in samples from the upper 1-inch layer.
Cadmium
Hawkes and Webb11 give the average cadmium content of soils as 0.5 ppm,
which is close to the geometric mean cadmium content of the soils collected
outside the Helena Valley in this investigation. This mean is estimated to be
approximately 0.8 ppm, and the range is from less than 0.5 to 2 ppm.
The highest cadmium content was found in soils collected near the smelter
stack; approximately 150 ppm cadmium was found in samples collected from
the upper 4-inch soil layer 0.67 mile northwest of the stack along traverse C. The
cadmium content of the upper 4-inch soil layer, like the lead and zinc content,
decreases systematically with distance from the stack, but no soils taken beyond
a distance of about 5 miles from the stack were found to contain more cadmium
than those soils sampled outside the Helena Valley. This does not necessarily
mean that cadmium contained in smelter stack emissions is less widely dispersed
than lead or zinc; cadmium is more difficult to assess because it is less abundant.
76 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
The cadmium content of soils collected at a depth of 6 to 10 inches is
one-fifth to one-tenth of that in soils of the upper 4-inch layer, indicating that
the chemical mobility of cadmium in the soils is somewhat greater than that of
lead, but less than that of zinc. This is in accord with the observed general
behavior of cadmium in soils as reported from studies in geochemical pros-
pecting.1 1
The upper 1 inch of uncultivated soil along the irrigation ditch north of East
Helena (traverse D) tends to contain more cadmium, in addition to lead and
zinc, than the cultivated soils along traverses A, B, and C.
The cadmium content of soils collected near the highway 2 miles west of
East Helena is no higher than that of other samples collected the same distance
from the smelter, but the samples collected near the tracks of the Northern
Pacific Railroad contain as much as 41 ppm cadmium.
Arsenic
The arsenic content of soils generally ranges from 1 to 50 ppm and averages
about 5 ppm.11 Samples collected in this investigation from the upper 4-inch
soil layer outside the Helena Valley have a geometric mean arsenic content of 6
ppm. The geometric mean for samples from a depth of 6 to 10 inches is only
about 1 ppm.
Soil samples collected from the upper 4-inch layer within a mile of the
smelter stack contain up to 150 ppm arsenic, and commonly contain more than
50 ppm. The arsenic content decreases systematically away from the stack for a
distance of 5 to 10 miles along traverses A and B, although the distribution of
arsenic in the soils along traverse C appears to be erratic.
The arsenic content of soil samples collected at a depth of 6 to 10 inches
indicates that the chemical mobility of arsenic in the soil, like that of cadmium,
is intermediate between the mobilities of lead and zinc. The soils at this depth
near the smelter tend to contain one-fourth to one-half as much arsenic as soils
in the upper 4-inch layer.
Samples from the upper 1 inch of soil collected near the highway west of
East Helena do not contain more arsenic than should be expected, considering
the distance of the sampling site from the smelter stack; those samples taken
near the railroad tracks, however, contain high amounts of arsenic in addition to
lead, zinc, and cadmium.
Other Elements
Spectrographic analyses for 25 additional elements were made on samples
selected at random from the total group of samples collected in this investi-
gation. Among the elements that appear to be highly concentrated in soils from
near the smelter, in addition to lead and zinc, are iron, silver, barium, cobalt,
chromium, copper, manganese, and vanadium. Further study would be required
to verifiy this, however.
Lead, Zinc, Cadmium, and Arsenic in Soils 77
-------
SUMMARY AND CONCLUSIONS
The soils of the Helena Valley are developed on fill materials derived from
the surrounding mountain ranges, and on lake sediment of Tertiary age. None of
the rock types that form the ranges are known to contain amounts of lead, zinc,
cadmium, and arsenic comparable to the amounts found in the Helena Valley
soils. The principal rock out-crops in or near the floor of the Valley are of
siltstone of the Belt Series of Precambrian age and of the lake sediments. The
lake sediments, rich in tuffaceous materials of volcanic origin, show no
detectable lead or arsenic, and only low to moderate amounts of zinc and
cadmium. Similarly, siltstones of the Belt Series were not found to contain any
appreciable quantities of any of these metals. Soils in the vicinity of, but
outside, the Helena Valley — and of the same type as present in the Helena
Valley — were found to contain no more lead, zinc, cadmium, and arsenic than is
characteristic of soils elsewhere.
Within a radius of at least 10 miles from the smelter at East Helena, the soils
contain abundantly more lead, zinc, cadmium, and arsenic than similar types of
soils in the vicinity of, but outside, the Helena Valley. They also contain far
more of .these metals than do soils of the United States in general. Lead occurs in
concentrations of up to 6800 ppm (0.68 percent), zinc in concentrations up to
5200 ppm (0.52 percent), cadmium in concentrations up to 160 ppm (0.016
percent), and arsenic in concentrations up to 150 ppm (0.015 percent). The
highest concentrations of these metals found in similar kinds of soil outside the
Helena Valley were 50 ppm lead, 75 ppm zinc, 2 ppm cadmium, and 20 ppm
arsenic.
The lead, zinc, cadmium, and arsenic contents of the soils decrease
systematically away from the smelter stack. The decrease is found to be linear
on log-log scales; the logarithm of the metal content decreases linearly with the
logarithm of the distance from the stack. This relationship is particularly well
defined in the upper 4-inch soil layer. For example, the lead content of a soil
sample from a depth of 0 to 4 inches, taken at a given distance ESE of the
smelter stack, can be predicted within a factor of 1.37, with a confidence of 95
percent. The zinc content of the same sample can be predicted within a factor of
1.44, cadmium within a factor of 1.22, and arsenic within a factor of 2.58, all at
the 95 percent level of confidence.
The extent of the area contaminated by emissions from the smelter stack is
best defined by the distribution of lead in the upper 4-inch soil layer. The
contamination extends in an east-southeast direction to the southern end of the
Spokane Hills, a distance of about 10 miles. Soils located just east of the pass at
the southeast end of the Valley, however, do not appear to have been
contaminated. Lead contamination of the soils extends for at least 5 miles
north-northeast from the smelter, and for 10 to 15 miles to the northwest.
Nearly all of the soils sampled in this investigation were collected in pairs,
one sample from the upper 4 inches and another at a depth of 6 to 10 inches.
The upper 4 inches of soil was cultivated at almost all of the sampling localities;
the soils at a depth of 6 to 10 inches were generally below the existing plow
78 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
layer. Uncultivated soils were sampled at three depth zones along an irrigation
ditch north of East Helena. The data indicate that lead, zinc, cadmium, and
arsenic have migrated downward for at least 6 to 10 inches in both cultivated
soils and in soils that have not been under cultivation for 20 years or more.
Comparison of the amounts of metals present in the surface soils with those at
depth indicates that zinc is the most mobile of the four elements studied. This
finding is in accord with previous observations of the chemical behavior of these
metals in soil environments. Lead, zinc, cadmium, and arsenic are present at a
depth of 6 to 10 inches in amounts ranging from 10 to 50 percent of the
amounts present in the upper 4-inch soil layer.
Soils along the highway 2 miles west of East Helena contain no more lead,
zinc, cadmium, or arsenic than other soils the same distance from the smelter.
Highway contamination — contamination caused by automobile exhaust, in
particular - appears to have been masked by contamination from the smelter
operation. Lead contamination of soils and vegetation along highways has been
found to be significant in other areas.12
Soils along the tracks of the Northern Pacific Railroad 2 miles west of East
Helena are contaminated with lead and zinc, and with cadmium and arsenic to a
lesser extent, beyond that which can reasonably be attributed directly to the
smelter. The contamination extends for a distance of 80 feet or more from the
tracks and probably results largely from railroad cars carrying ores and ore
concentrates to and from the smelter.
The arithmetic mean concentrations of lead, zinc, cadmium, and arsenic in
the upper 4-inch soil layer within a radius of 0.67 to 10 miles from the smelter
stack at East Helena, estimated by integration of the appropriate regression
equations, are as follows:
1. Lead — 69 ppm.
2. Zinc - 79 ppm.
3. Cadmium — 2.5 ppm.
4. Arsenic — 11 ppm.
Similar estimates for the 6- to 10-inch depth zone are:
1. Lead-22 ppm.
2. Zinc — 58 ppm.
3. Cadmium— 1 ppm.
4. Arsenic — 7 ppm.
Assuming that the original metal contents of the soils were similar to the
rrieari concentrations of the metals in the soil samples collected outside the
Helena Valley in this investigation, the amounts of each that have been added by
smelter contamination to the upper 10 inches of soil in the area beyond 0.67
mile from the smelter are as follows:
1. Lead- 10,000 tons.
2. Zinc-5,600 tons.
3. Cadmium - 290 tons.
4. Arsenic — 860 tons.
Lead; Zinc, Cadmium, and Arsenic in Soils 79
-------
REFERENCES FOR CHAPTER 4
1. Mertie, J. B., Jr., R. P. Fischer, and S. W. Hobbs. Geology of the
Canyon Ferry Quadrangle, Montana. U.S. Geol. Survey Bull. 972. p.
97.1951.
2. Pardee, J. T. and F. C. Schrader. Metalliferous Deposits of the
Greater Helena Mining Region, Montana. U.S. Geol. Survey Bull.
842.p.318. 1933.
3. Huffman, Claude, Jr., and J. A. Thomas. Unpublished atomic
absorption technique. U.S. Geological Survey, Denver, Colorado.
4. Nakagawa, H. M. and T. F. Harms. Atomic Absorption Determi-
nation of Cadmium in Geologic Materials. U.S. Geol. Survey Prof.
Paper 600-D. p. D207-D209. 1968.
5. Huffman, Claude, Jr. Copper, Strontium, and Zinc Content of U.S.
Geological Survey Silicate Rock Standards. U.S. Geol. Survey Prof.
Paper 600-B. p. B110-B111.1968.
6. Ward, F. N. et al. Analytical Methods Used in Geochemical
Exploration by the U.S. Geological Survey. U.S. Geol. Bull. 1152.
p. 100. 1963.
7. Shacklettee, H. T., J. C. Hamilton, J. G. Boerngen, and J. M.
Bowles. Elemental Composition of Surficial Materials in the Con-
terminous U.S. U.S. Geol. Survey Prof. Paper 574-D. (In press.)
8. Cohen, A. C., Jr. Tables for Maximum Likelihood Estimates; Singly
Truncated and Singly Censored Samples. Technometrics,
J(4):535-541. 1961.
9. Miesch, A. T. Methods of Computation of Estimating Geochemical
Abundance. U.S. Geol. Survey Prof. Paper 574-B.p.l5. 1967.
10. Canney, F. C. Geochemical Study of Soil Contamination in the
Coeur D'Alene District, Shoshone County, Idaho. Mining Engi-
neering, 1 J(2):205-210. 1959.
11. Hawkes, H. E. and J. S. Webb. Geochemistry in Mineral Explo-
ration. Harper and Row, Inc., New York. p.415. 1962.
12. Cannon, H. G. and J. M. Bowles. Contamination of Vegetation by
Tetraethyl Lead. Science, 757(3532): 765-766. 1962.
80 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
5. SOIL AND VEGETATION STUDY
Ibrahim J, Hindawi, Ph.D., and Grady E. Neely
ENVIRONMENTAL PROTECTION AGENCY
National Environmental Research Center
INTRODUCTION
During the summer of 1969, a study was undertaken in the Helena Valley
area of Montana to determine the effects pollutants were having on area
vegetation. The pollutants of interest were arsenic, cadmium, lead, zinc, and
sulfur dioxide.
The investigation had three purposes: (1) to determine how vegetation is
being contaminated by heavy metals, (2) to determine the concentrations of
heavy metals being accumulated in vegetation in the area, and (3) to assess any
sulfur dioxide damage that might be occurring in the Valley.
ORIGIN OF HEAVY METALS IN VEGETATION
Methods and Materials
To determine how suspected pollutants were affecting vegetation in the
Helena Valley area, certain plants - indigenous to the area - were grown under
controlled conditions at four locations in the study area from June 27 through
September 4, 1969, a period of 10 weeks. The two suspected media of transfer
were air and soil. A small, cylindrically shaped, glass-fiber greenhouse, 6 by 6.5
feet (Figure 5-1), was located at each of the four sites. In relation to the stack of
the American Smelting and Refining Company (ASARCO), station 1 was 0.8
mile northeast; station 2 was 2.5 miles east; station 3 was 0.4 mile southeast; and
station 4 was 4.5 miles west, as indicated in Figure 5.2. Fans in the greenhouses
were designed to circulate air through at one change per minute. Two additional
greenhouses were placed at station 1. These were equipped with particulate and
activated-charcoal filters for the purpose of purifying the air inside the shelters.
Four of the plants studied — alfalfa, pinto bean, carrot, and beet — were
selected because they are commonly grown and are consumed by both man and
animals in the study area. Two others — petunia and tobacco — were included
because of their sensitivity to SO2.
All plants in the ambient-air greenhouses and those in one of the purified-air
shelters were grown hydroponically in a vermiculite support medium. Plants in
8-inch plastic pots were placed in shallow plastic trays to which a distilled-water
81
-------
. '*.
Figure 5-1. Control and exposed plant sites at station 1.
nutrient solution was added twice a week. The potted plants were flushed
weekly with distilled water, and the trays were cleaned weekly to rid them of
algae.
In the remaining greenhouse supplied with purified air, plants were grown in
plastic pots containing one of two soils. One soil (East Helena) was expected to
exhibit a high range of heavy-metals concentration, and the other (East Helena
composite) was thought to possess a medium range of concentration relative to
the metal content of the soil in the immediate East Helena area. The former was
taken from 0.6 mile southeast of the town; the latter was composed of equal
amounts of soil from four locations between 0.5 and 1 mile of East Helena on
the north, east, south, and west sides of town. The soil composite from the tour
locations was mixed thoroughly before being placed in the pots. All plants
grown in soil-containing pots were watered with distilled water and nutrient
solution approximately three times a week. Identical plants were planted in a
small garden at each of the four locations. These plants were watered with
distilled water and nutrient solution approximately two times a week.
At the end of the 10-week period, unwashed plant samples were sent to the
U.S. Food and Drug Laboratory at Denver, Colorado, for analyses. Cadmium,
lead, and 7,inc analyses were performed by means of atomic absorption
spectrophotometry. Arsenic was analyzed by the silver diethyldithiocarbamate
method. All plant-sample concentrations were expressed in parts per million
(ppm) on a wet-weight basis. Soil samples that corresponded to the vegetation
samples were sent to the U.S. Geological Survey in Denver for analyses.
Soil-sample concentrations were expressed in ppm on a dry-weight basis.
82 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
CO
o
re
o
3
OS
EAST HELENA
Figure 5-2. Locations of greenhouses and experimental gardens in the East Helena study.
oo
-------
Results and Discussion
Table 5-1 presents the metal contents of samples of vermiculite and soils
used to grow the vegetation during the study. The metal content of vermiculite
did not change with use and was lower than the metal content of any of the soils
used during the study. The soil with the highest metal content came from station
3, and the one with the lowest came from station 4.
Table 5-1. HEAVY-METAL CONTENT OF VERMICULITE
AND SOILS USED IN GREENHOUSES AND EXPERIMENTAL GARDENS
(ppm)
Material
Unused vermiculite
Used vermiculite
E Helena soil
E Helena soil composite
Soil at station 1
Soil at station 2
Soil at station 3 . . .
Soil at station 4
Arsenic
<5
<5
35
35
35
25
50
8
Cadmium
1 5
1 5
19.0
16 5
21 0
6.5
56.0
2.0
Lead
30
30
615
490
925
190
1,525
85
Zinc
7^
7R
?no
???
4^
126
418
83
Table 5-2 gives the metal contents for the vegetation samples. A composite
of all the plants grown was taken to form a single sample for each growing
procedure. A comparison of the analyses of hydroponically grown vegetation
with the analyses of that grown in ambient air reveals that neither metals in
fine-particle form nor those in the gaseous state were a major source of the
heavy metals that accumulated in the vegetation. Although the vegetation from
station 3 had significantly higher metal contents, this was probably caused by
particulate matter adhering to the plant surfaces. At this station near the end of
the study period, a sudden wind storm deposited surface soil on the plant leaves
while the pots and trays were being cleaned outside the greenhouse. At the close
of the study, this same particulate matter was still on the leaves — especially the
sticky and pubescent surfaces of tobacco and petunia.
Plants grown in soil inside the filtered-air greenhouse had higher concentra-
tions of metals than did the plants grown in vermiculite. A comparison of both
analyses confirms that plants are capable of accumulating arsenic, cadmium, and
zinc through their root systems. Because there was no significant difference in
lead concentrations, however, it may be possible that lead is not assimilated
through the root system.
84 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 5-2. AVERAGE HEAVY-METAL CONTENT
OF EXPERIMENTAL VEGETATION a
(ppm)
Where grown
Greenhouse in vermiculite
Station 1 — Control filtered air
Station 1 — Exposed to ambient air
Station 2 — Exposed to ambient air
Station 3 — Exposed to ambient air
Station 4 — Exposed to ambient air
Greenhouse in soil
Station 1 — E. Helena soil in
filtered air
Station 1 — E. Helena composite soil
in filtered air
Experimental gardens in soil
Station 1
Station 2
Station 3
Station 4
Arsenic
0.1
0.4
>0.0
1.7
>0.0
1.7
1.6
2.5b'c
1.0
84d
0.4C
Cadmium
0.1
0.3
0.1
0.9
0.2
5.2
3.0
8.6b'c
1 3
75d
0.7C
Lead
3.5
2.6
1.5
7.4
0.6
5.1
2.9
5.4b'c
3.0
48.3d
1.0C
Zinc
6.8
8.2
5.6
14.0
3.0
67.8
14.0
60.5b'c
13 1
i *j. i
52.2
11. 5C
aSamples were not washed prior to analyses.
Alfalfa not included here because of lost sample.
c Lettuce is included in the average.
Pinto bean is not included in the average.
Figures 5-3 and 5-4 reveal that the concentrations of metals in or on the
plants varied directly with the concentrations found in the soils in which the
plants were grown. This was true for lead as well as arsenic, cadmium, and zinc.
Because none of the samples were washed prior to analysis, it can not be
concluded that the metals found had accumulated in the plant tissue. Some of
the metal content could have come from windblown or rain-splattered surface
soil or from large particles settling from the air on the plant surfaces.
Soil and Vegetation Study
85
-------
oo
ON
ffi
W
W
z
tn
w
z
O
z
H
O
r
r
G
O
Z
C/3
c
O
60
50
40
« 30
20
10
ARSENIC
CADMIUM
LEAD
ZINC
1234
1234 1234
STATION NUMBER
1234
Figure 5-3. Average heavy-metal levels in plants grown in
experimental gardens around East Helena in 1969.
-------
to
D.
s
t/i
1500
1300
1100
Q.
!: 900-
c
3
Jj
£ 700
a
5001- ARSENIC
300
100-
CADMIUM
LEAD
ZINC
LL
oo
1234 1234 1234 123^
STATION NUMBER
Figure 5-4. Heavy-metal content of soils in experimental gardens
around East Helena in 1969.
-------
SUMMARY
Arsenic, cadmium, lead, and zinc in the forms of gases or fine particles are
not a major source of vegetable contamination in the Helena Valley.
Arsenic, cadmium, and zinc can be assimilated into the plant tissues through
the plant root system.
The arsenic, cadmium, lead, and zinc concentrations found in the experi-
mentally grown vegetation in the study area varied directly with the metal
concentrations found in the soil.
AMOUNT OF HEAVY METALS IN SOILS AND VEGETATION
Methods and Materials
Random samples of edible portions of garden vegetables and crops were
taken from within 4 miles of East Helena during August and September of 1969.
Surface-soil samples, from a depth of 6 inches, were also taken from these same
locations.
Both the plant and soil samples were sent to Denver, Colorado, for
analyses—the former by the U.S. Food and Drug Administration, and the latter
by the U.S. Geological Survey.
Results and Discussion of Soil Analyses
The analyses for arsenic, cadmium, lead, and zinc contents of the soils
generally indicated that the concentrations of these metals varied inversely with
the distance from the smelter. Soil samples were consistent in that if a sample
contained a high concentration of one metal, then the other metals were also
present in high concentrations. This characteristic was true for medium and low
values as well.
Grasslands in the Helena area are tilled very infrequently, and the alfalfa
fields are tilled about once every 5 years. The gardens and wheat, barley, and oat
fields are plowed yearly, however. A comparison of the analyses of soil samples
indicates that the concentrations of metals were highest in the soils of grass and
alfalfa; concentrations found in the soils of the gardens and wheat, barley, and
oat fields were somewhat lower. This finding indicates that the metal concen-
trations are building up in the soil from the surface down. The more often soils
are tilled, the more thoroughly the plow layer is mixed and the faster that
leaching of metals takes place.
The 69 soils sampled within 4.5 miles of the smelter had metal contents
ranging from 5 to 160 ppm for arsenic, 2 to 42 ppm for cadmium, 65 to 1530
ppm for lead, and 70 to 9400 ppm for zinc. The ranges of these values are much
greater than normally would have been expected in soil samples from such a
small area.
88 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Results and Discussion of Vegetation Analyses
Concentrations of arsenic, cadmium, lead, and zinc in wheat kernels, barley
kernels, oat kernels, pasture grass, alfalfa, and lettuce in the East Helena area did
not indicate an inverse relationship with distance from the smelter. As was true
with soil analyses, however, vegetation samples in the same area indicated
pasture grasses contained greater metal concentrations than alfalfa, and alfalfa
contained higher levels than wheat, barley, oats, and most garden vegetables.
For each metal, the overall concentration range, on a wet-weight basis, was:
arsenic, 0 to 12 ppm; cadmium, a trace to 9.8 ppm; lead, a trace to 100 ppm;
and zinc, 0.5 to 232 ppm.
The ranges of heavy metals found in plant species sampled from residential
gardens and ranches within 4 miles of East Helena are presented in Table 5-3.
Table 5-3. RANGES OF HEAVY METALS IN PLANTS
SAMPLED FROM RESIDENTAIL GARDENS AND RANCHES
IN EAST HELENA AREA
Plant type
Garden
Apple
Beet
Cabbage
Carrot
Kohlrabi
Lettuce
Onion
Potato
Radish
Rutabaga
String bean
Sunflower leaf
Sweet pea
Field
Alfalfa
Barley kernel
Barley straw
Oat kernel
Pasture grass
Wheat kernel
No. of
samples
2
9
5
11
2
10
5
10
1
1
2
1
4
16
8
1
1
11
24
Metal range, ppma
Arsenic
Tb- 0.1
0.0- 0.4
0.0- 0.9
0.0- 2.9
T- 0.1
0.0- 2.1
T- 3.2
0.0- 0.1
T
0.5
T
3.3
T- 0.1
0.4- 5.7
0.0- 0.9
14.3
0.1
2.5 - 12.0
T- 0.0
Cadmium
T-0.1
0.1 -2.5
T-0.4
0.1 -0.4
0.1 -0.2
0.2 - 3.4
0.1 - 0.5
Tc - 0.2
0.6
°-3^
0.1d
1.0
T- 0.2
0.3 - 3.2
0.1 - 1.2
6.3
0.6
1.2-9.8
0.1 - 1.5
Lead
0.7 - 0.8
0.4 - 15.0
T- 8.6
0.3- 4.0
0.1 - 4.1
1.2- 17.2
0.4- 1.8
0.1- 1.3
3.4
3.1
0.1 - 0.2
15.4
0.4- 1.5
2.5- 42.0
0.3 - 9.8
142.8
1.1
1.4- 100.0
0.1 - 1.5
Zinc
0.5- 1.9
4.1 - 67.1
2.2- 15.1
3.1 - 35.5
3.5 - 8.9
6.1 - 36.1
6.2- 17.4
3.0- 8.4
12.0
7.0
4.4- 7.1
27.0
7.4- 21.9
24.0- 124.0
23.0- 73.0
105.9
32.2
56.0 - 232.0
33.0- 86.0
On a wet-weight basis.
Trace < 0.05 ppm.
Only nine samples.
Only one sample.
Soil and Vegetation Study
89
-------
These ranges varied greatly from species to species. A grouping of vegetation by
type in Table 5-4 showed definite rankings. From highest to lowest concen-
tration, the ranking was pasture grasses, alfalfa, garden plants, and small grains.
The highest metal levels found in the grasses ranged from 3 to 10 times higher
than the highest levels found in small grains.
Table 5-4. RANGES OF HEAVY METALS IN GARDEN PLANTS,
SMALL GRAINS, ALFALFA, AND PASTURE GRASSES
SAMPLED IN EAST HELENA AREA IN 1969
Plant type
Garden
Small grain
Alfalfa
Pasture grass
Metal range, ppm a
Arsenic
0 - 3.3
0 - 0.9
0.4- 5.7
2.5- 12.0
Cadmium
Tb - 3.4
0.1 - 1.2
0.3 - 3.2
1.2-9.8
Lead
T- 17.2
0.1 - 9.8
2.5- 4ZO
1.4- 100.0
Zinc
0.5- 67.1
23.0- 73.0
24.0- 124.0
56.0 - 232.0
aOn a wet-weight basis.
bT< 0.05 ppm.
SUMMARY
Generally, soil concentrations of each metal studied varied inversely with
distance from the stack. Soils that had high concentrations of one metal usually
had high concentrations of the other metals studied. This similarity also held
true for lesser concentrations. Soil metal concentrations varied inversely with
frequency of soil tillage; this indicated a metal buildup from the surface
downward. The concentration ranges for arsenic, cadmium, lead, and zinc in
soils varied more than normally would have been expected in such a small area.
Concentrations of arsenic, cadmium, lead, and zinc in vegetation from the
study area varied more than would have been expected in an area of similar size.
Factors affecting the amount of metals found in vegetation in the study area
were soil metal levels, plant species, and portions of plant sampled.
VISIBLE PLANT DAMAGE TO INDIGENOUS
AND GREENHOUSE VEGETATION
Methods and Materials
Information concerning the visible effects of sulfur dioxide on both
indigenous and experimentally grown vegetation was gathered in the study area
during the 1969 growing season. Inspection tours were made by the staff of the
Vegetation Effects Section to find the incidence of sulfur dioxide damage to
indigenous vegetation. These inspections consisted of observing vegetation at
several locations throughout the study area.
An assessment of possible visible injury by air pollutants to experimentally
grown vegetation was made at the end of the study. The methods and materials
90 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
used to grow the experimental vegetation were listed earlier in this chapter. Only
vegetation grown in vermiculite in greenhouses was assessed for damage.
Comparisons of growth suppression and dwarfing were not made among plants
grown in vermiculite.
Results and Discussion
The findings made from the indigenous vegetation inspection tours in the
study area are reported in Table 5-5. Sulfur dioxide plus acid-mist injury
Table 5-5. INJURY FOUND ON INDIGENOUS VEGETATION
Date
6/20/69
7/22/69
7/22/69
7/22/69
7/22/69
7/22/69
8/26/69
Plant
Alfalfa
Hedges,
English
hawthorne,
sun flower,
mock orange,
blueberry
Columbine
Lilac
sweet pea,
apple,
tomato.
lettuce
Grape,
rhubarb.
plum,
corn,
sweet potato
Alfalfa
apple.
mustard
Pansy,
petunia,
sweet pea.
dahlia,
columbine
Location
Tom Dartmen residence.
1800 yards north of
ASA R CO
Park in East Helena,
1000 yards north
of ASA R CO
A.J. Vollmer residence.
800 yards east of
AS A R CO
Paul Kleffner residence,
1800 yards southeast
of ASARCO
Gregory Schaff residence.
1200 yards northeast
of ASARCO
George Marcinkowski
residence, 1200
yards south of ASARCO
Vollmer residence
Type injury
so2
S02 + acid mist
S02 + acid mist
S02 + acid mist
S02 + acid mist
S02 + acid mist
so2
so2
so2
so2
so2
so2
so2
so2
SO 2
so2
so2
S02 + acid mist
so2
SO2+ acid mist
so2
so2
so2
so2
so2
Degree of
damage3
M
E
M
M
T
M
E
T
E
M
M
T
E
T
M
T
E
M
M
T
T
M
E
M
M
T (trace) = 0 to 5 percent of leaf area damaged; M (moderate) = 5 to 25 percent
of leaf area damaged; E (extensive) = 25 to 50 percent of leaf area damaged.
Soil and Vegetation Study
91
-------
developed on several plant varieties at two locations. Sulfur dioxide alone was
the cause of leaf injury at the other locations. All locations where injury was
found were within 1 mile of the stack of American Smelting and Refining
Company.
Table 5-6 summarizes the leaf damage found on the experimental vegetation
at three sites. In this table, both type and amount of damage are listed. When the
type of injury is specific to a certain pollutant, it is listed according to pollutant;
however, if the type is nonspecific, it is listed according to type of damage, such
Table 5-6. TYPE AND EXTENT OF LEAF DAMAGE
ON EXPERIMENTAL VEGETATION
Damage type/Plant species
Sulfur dioxide
Tobacco . . . . . ...
Pinto bean
Petunia
Alfalfa
Beet . ....
Carrot
Ozone
Tobacco . . .
Synergistic (S02 + Og)
Tobacco ....
Pinto bean
Chlorosis
Tobacco . .
Pinto bean ...
Petunia
Alfalfa
Beet . .
Carrot
Degree of injury at three locations3
1
T
T
T
T
T
T
2
T
T
T
T
M
M
M
M
T
T
T
3
M
E
M
M
M
M
T
aT (trace) = 0 to 5 percent of leaf area damaged.
M (moderate) = 5 to 25 percent of leaf area damaged.
E (extensive) = 25 to 50 percent of leaf area damaged.
as chlorosis. An example of the sulfur dioxide injury found on alfalfa leaves at
station 3 is shown in Figure 5-5.
Relatively low concentrations of ozone and sulfur dioxide, when mixed, will
cause damage to vegetation. Evidence of damage from mixture of these
pollutants was observed on vegetation at stations 1 and 3. The combination of
ozone and sulfur dioxide reduces the injury threshold of the leaf tissue and
increases the damage beyond that from the individual pollutants.
92 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Figure 5-5. Sulfur dioxide leaf injury to alfalfa at station 3.
In addition to tissue destruction, the growth of experimental vegetation,
except at station 4, was suppressed. Table 5-7 lists the percentage by which
exposure specimens were smaller than the controls specimens of the same age.
A suppression value of 20 percent means that the plant growth in an
exposure chamber was estimated by visual comparison to be 20 percent less than
that of a similar plant grown in the control site.
Table 5-7. GROWTH SUPPRESSION OF EXPERIMENTAL VEGETATION
(% < control)
Plant
Tobacco
Pinto bean
Petunia
Alfalfa .
Beet
Carrot
Control
1
0
0
0
0
0
0
Exposed
1
30
10
15
10
10
10
2
20
15
10
10
10
15
3
30
15
20
20
15
15
4
0
0
0
0
0
0
Suppression of growth at stations 1 and 3 was noticed in experimental
vegetation grown in soil.
Soil and Vegetation Study
93
-------
SUMMARY
Study and observations of the indigenous and selective vegetation revealed
plant injury by sulfur dioxide and/or acid mist in several locations north,
northeast, and east of the American Smelting and Refining Company. Damage
from mixtures of ozone and sulfur dioxide was noticed at location sites 1 and 3.
Dwarfing and growth suppression were observed in vegetation grown at locations
1, 2, and 3,whereas normal and healthy growth was noticed at location 4.
94 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
6. EFFECTS OF AIR POLLUTION
ON INDIGENOUS ANIMALS AND VEGETATION
C. C. Gordon, Ph.D.
UNIVERSITY OF MONTANA
Department of Botany
INTRODUCTION
Investigations were undertaken (1) to document the association between
concentrations of lead and cadmium in indigenous vegetation and in animals
ingesting such vegetation, (2) to determine whether the accumulation of lead
and cadmium in the vegetation surrounding the East Helena smelters results
from absorption of the metals through the roots from the soil or through the
leaf surfaces from the atmosphere, and (3) to assess the effects of sulfur dioxide
on plants in the study area.
Five studies were initiated to accomplish the three objectives. The first
study was to determine the extent of accumulation of lead and cadmium in
indigenous animals and in the grasses upon which they feed. A second study was
to quantitate the lead and cadmium content of garden vegetables growing in the
area. The third study involved transfer of East Helena soil from several sites to
Missoula, where vegetables (primarily lettuce) were grown and then assayed for
lead and cadmium. A fourth study involved the feeding of rabbits with lettuce
grown in several locations to determine the amount of accumulation of lead and
cadmium in rabbit tissues as related to the food source. The fifth study was to
examine indigenous conifer vegetation for damage produced by air pollution.
ACCUMULATION OF LEAD AND CADMIUM
IN INDIGENOUS ANIMALS
During the months of July to November 1969, several species of rodents
were captured in the vicinity of East Helena. These were: Citellus columbianus
(Columbia ground squirrel), Mus musculus (house mouse),/', leucopus (white-
footed deer mouse), Eutamius amoenus (yellow pine chipmunk), Microtus
pennsylvanicus (meadow vole), M. momtarius (montane vole), M. logicaudis
(long-tailed vole), Lepus townsendii (white-tailed jackra.bbii),Sylvilagus nuttallii
(mountain cottontail).
Approximately 135 animals were collected from 28 sites, some of which are
shown in Figure 6-1. Small rodents were collected by live traps; the traps were
95
-------
STATION LOCATION
1 M.v. JOHNSON RESIDENCE
2 RACETRACK
3 EAST HELENA DUMP
4 MARCHE RESIDENCE
5 KLEFFNER RESIDENCE
6 SUMNER RESIDENCE
7 ARMAGAST RESIDENCE
8 ARLIENT RESIDENCE
9 LAMPING RESIDENCE
10 PRICKLY PEAR BRIDGE ON LAMPING LAND
11 0.4 MILE NORTH OF GRAVEL PIT BY ARLIENT'S CROSSING
12 HALFWAY BETWEEN EAST HELENA AND OVERPASS
13 ACROSS ROAD FROM ASARCO NEAR DUMP
16 VOLMER RESIDENCE
17 DIEHL RESIDENCE
IB R.F. MILLER RESIDENCE
19 0.25 MILE SOUTH OF STACK ALONG ROAD
20 0.5 MILE SOUTH OF STACK ALONG ROAD
21 MARCHIE ABANDONED FARM
22 0.5 MILE NORTH OF SUMNER RESIDENCE ON RAILROAD TRACK
23 1000 YARDS EAST OF VOLMER RESIDENCE IN A CULVERT
24 600 YARDS SOUTHEAST OF ROOTBEER STAND
25 AT DUMP 1000 YARDS EAST OF SITE 24
26 ROCK PILE 1000 YARDS NORTHEAST OF JUNCTION OF HIGHWAY
12 AND MONTANA AVENUE
33 BUFF RESIDENCE
37 BESSLER RESIDENCE
39 J. FINN RESIDENCE
X ASARCO STACK
Figure 6-1. Animal collection sites.
-------
set out one day and collected the next. The eight rabbits were shot or captured
by hand. The animals were frozen immediately if dissection was not possible
that day. In the laboratory liver and kidneys (and, in some cases, bones) were
removed and frozen separately in plastic bags. The livers and kidneys of mice
from one or several adjacent sites were combined in a composite in order to give
enough tissue for assay. Rabbits and ground squirrels were reported indepen-
dently because their feeding habits and accumulation patterns were considered
to be radically different from those of mice. Six rabbits and one pig were
included in the 1969 study. Control animals were taken from two areas, one at
MacDonalds Pass (17 miles west of the study area) and the other at Potomac
Valley (100 miles WNW of Helena).
Lead and cadmium analyses were done by the Wisconsin Alumni Research
Foundation (WARF) Institute, Inc., of Madison, Wisconsin. The method used
was atomic absorption spectrophotometry. The results of the analyses are shown
in Table 6-1.
Table 6-1. LEAD AND CADMIUM IN ANIMAL TISSUES3
(ppm)
Site
2,3
4,6
5,22
7,8,26
9,1
16
23,24,25
21
27
28,38
19,20
Potomac
Valley
MacDonald
Pass
1,3,10,
11,12
6
6
21
6
6
Missoula
6
Number of
animals
9
6
8
5
8
9
11
9
8
7
11
12
4
5
1
1
1
1
1
1
1
Specimen
Mice
Mice
Mice
Mice
Mice
Mice
Mice
Mice
Mice
Mice
Mice
Mice
Columbia
ground
squirrels
Columbia
ground
squirrels
Rabbit
Rabbit
Rabbit
Rabbit
Rabbit
Rabbit
Pig
Lead
Bone Liver
10.0
14.0
3.2
4.7
15.0
23.0
4.7
4.7
1.2
0.5
2.2
2.0
4.1
0.8
2.6
3.9
3.6
5.1
7.7
<0.5
73 2.6
Kidney
58.0
62.0
8.0
26.0
110.0
48.0
53.0
88.0
2.4
0.5
12.0
0.5
0.7
2.0
3.4
3.1
2.3
3.9
19.0
<0.5
2.7
Cadmium
Liver
1.7
0.5
0.5
2.2
0.4
2.4
2.7
0.8
0.2
0.2
4.7
0.2
0.2
1.4
5.8
5.8
9.1
3.9
4.9
0.1
0.2
Kidney
7.7
1.8
2.1
6.0
2.0
3.8
7.2
1.8
1.5
2.4
14.0
0.6
1.4
4.0
61.0
34.0
53.0
29.0
19.0
0.3
0.8
Fresh weight.
Effects of Air Pollution on Indigenous Animals and Vegetation 97
-------
Because rodents are dependent upon the vegetation growing in the area,
they are good indicators of the transfer of pollutants from the air into the
natural food chain. In Table 6-2 are descriptions of the rodents trapped and
pertinent information such as territorial range and eating habits. The effect on
such wildlife populations as these rodents is more severe and more readily
evident than on humans or domestic animals whose diet is only partly derived
from locally grown foods. Beginning at conception, an indigenous animal is
subjected to total-environment exposure.
Several trends emerged from the rodent data. One, expected from state-
ments in the literature, was that different species accumulate lead and cadmium
in different amounts. This fact is undoubtedly related to physiological as well as
dietary differences. The five rabbits from East Helena that were eating the
indigenous grasses showed a very high level of cadmium in kidneys, as shown in
Table 6-1. The composite samples of Columbia ground squirrel kidneys also
showed a moderate accumulation of cadmium (4.0 ppm). In contrast, the
cadmium concentration of kidney composites of mice ranged from 1.5 to 14.0
ppm. From this evidence it is apparent that species in an area will be affected
differently by a pollutant level, at least insofar as accumulation in body tissues is
concerned. Thus, in estimating contamination of an ecosystem by means of
evaluation of tissue concentrations, the tissue levels of the animal chosen for
analysis must be compared to both normal and experimentally produced levels.
A second trend observed was that, in mice, accumulation of lead in the
kidneys was many times greater than in the liver. This relationship was not
evident in Columbia ground squirrels or in rabbits, where levels were more or less
equal.
In mice from the East Helena area, lead levels in the liver ranged from 3.2 to
23 ppm and in kidneys from 8 to 110 ppm (fresh-weight basis).
The four rabbits from site 6 were domestic rabbits that had escaped; they
had been eating the native vegetation for unknown periods of time. The rabbit
from site 21 was a native rabbit, and the rabbit from site 14 was a domestic
rabbit — a control selected to represent normal levels in rabbits. There is an
obvious difference between the concentrations of metal found in the control
rabbit and those found in the five rabbits eating indigenous vegetation in the
East Helena area, especially in cadmium concentrations found in the kidneys.
The one pig assayed was one that died at site 6. Although the cause of death
could not be defined, the bone lead level was 73 ppm.
In comparing the concentrations of lead and cadmium in rodent tissues and
relating the levels to distance from the smelter, no definite correlation between
concentrations of lead or cadmium in animals and distance from the ASARCO
smelter stack is obvious. The highest levels of lead in rodent tissues were
measured in samples from sites 1 and 9, two of the more distant collection sites,
considering predominant wind direction. Tissue from sites 2 and 3, closer and in
the same direction as sites 1 and 9, had lower lead levels. The lowest levels of
98 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 6-2. ACCOUNTS OF SPECIES TAKEN IN EAST HELENA AREA,
SUMMER 1969
Species
Remarks
Microtus pennsylvanicus
(meadow mouse)
Peromuscus maniculatus
(deer mouse)
Mus musculus
(house mouse)
Citellus columbianus
(Columbian ground
squirrel)
Food — Grasses and sedges, roots and bulbs. Stom-
ach analysis—corn, barley, wheat, oats, clover,
alfalfa, blue grass, broom sedge, bulrush, dock,
strawberry, buttercup, goldenrod, rosin weed,
ragweed, sunflower, willow, maple, poplar, oak,
and apple.
Habitat — Members of this subfamily (Microtinae)
are found almost everywhere in the U.S. (with
the exception of three southeastern states)
where there is good grass cover. They are
widely distributed from swamps to semibarren
plains and from sea level to high mountains and
are usually found in large numbers in meadows
and grasslands.
Discussion — The presence of M. pennsylvanicus
may be detected by runways,
Food — Seed, insects, berries, nuts in season,
fruits, tubers, grains, and dry vegetable foods.
Habitat — This nocturnal mouse is widely distrib-
uted from grasslands to forest. It is one of our
commonest rodents south of the Arctic Circle.
The home ranges vary from less than an acre for
females up to roughly five acres for males.
Discussion — The life span in the wild rarely ex-
ceeds 2 years. Almost complete annual turnover
in the P. maniculatus population on the Edwin
S. George Reserve in Michigan.
Food — Almost anything man eats, partial to cere-
als and vegetable products
Habitat — Cities or fields, waste places. M. muscu-
lus is found around human habitations and of-
ten in fields, especially grain fields.
Discussion — Found wherever man's buildings are
located.
Food — Great variety of herbage, flowers, seeds,
bulbs, fruits, some insects, nuts, grains, green
vegetation, roots, young birds, and mammals.
Habitat — Found in mountain meadows and grassy
areas.
Effects of Air Pollution on Indigenous Animals and Vegetation 99
-------
Table 6-2 (continued). ACCOUNTS OF SPECIES TAKEN IN
EAST HELENA AREA, SUMMER 1969
Species
Remarks
Eutamias amoenus
(yellow pine
chipmunk)
Peromyscus leucopus
(wood mouse)
Microtus montanus
(Montana vole)
M. longicandus
(longtail vole)
Sylvilagus nuttalii
(mountain cottontail)
Orycto/agus cuniculus
(domestic rabbit)
Discussion — Found in grassy areas where it can
burrow. Normally found in colonies.
Food — Seeds, fruits, insects, berries, nuts, buds,
etc.
Habitat — Found primarily in the Yellow Pine For-
ests.
Discussion — Lives in burrows underground.
Food — wide variety. Some insects.
Habitat — Deciduous forest. Woods and brushy
areas. Varied.
Discussion — Found in Eastern deciduous forests.
Found in eastern Montana in wooded and brushy
bottoms.
Food — Grass and leaves.
Habitat —Dry grassland and sagebrush-grassland.
Discussion — Found in Rocky Mountains to the
Sierra-Cascades. Population densities vary
widely.
Food — Grass and leaves.
Habitat — Wet areas in absence of M. pennsylvani-
cus.
Discussion — Occupies altitudes from alpine to val-
ley bottom. Found in eastern deciduous forests.
Found in eastern Montana in wooded and brushy
bottoms. Population density is usually low.
Food — Grass, shrub twigs, and bark. Most vegeta-
tion.
Habitat — Shrubby gullies, forest edges, stream
bottoms.
Discussion — Found throughout Montana.
Food - Grass, shrub twigs, and bark. Most vegeta-
tion.
Habitat — Seldom far from dwellings. Shrubby
areas or woody edges.
100 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 6-2 (continued). ACCOUNTS OF SPECIES TAKEN IN
EAST HELENA AREA, SUMMER 1969
Species
Remarks
Lepus townsendi!
(white-tailed jack
rabbit)
Food — Grass, shrub twigs, and bark. Most vegeta-
tion.
Habitat —Grassland and sagebrush areas. Alpine
areas of some mountain ranges.
Discussion — Found in northwestern U.S. Less
common west of the Continental Divide.
lead were found in rodent tissue from sites 5 and 22, two of the sites closest to
the smelter. Obviously, for the mouse population, distance and wind direction
are not the major factors in accumulation, at least within the distance surveyed.
In conjunction with the rodent-trapping project, soil and grass were
collected from each site where rodents were trapped. The results of the analyses
on these soil and grass collections are shown in Table 6-3.
Table 6-3. LEAD AND CADMIUM CONCENTRATIONS
OF SOIL, GRASS, AND RODENT TISSUES
(ppm)
Rodent trapping
site
1,9
2,3
13,19,20
4,6
5,22
23,24,25
17,18
7,8,26
16
21
Lead
Soil3
600
1600
440
680
370
425
270
Grass3
350
28
92
7C
50
20
160
Liverb
15.0
10.0
1.8
14.0
3.2
4.7
11.0
4.7
23.0
4.7
Kidneyb
110
58
11
62
8
53
110
26
48
88
Cadmium
Soil3
23
33
8
22
10
14
6
Grass3
6
2
5
1C
1
1
7
Liverb
0.4
1.7
16.0
0.5
0.5
2.7
0.2
2.2
2.4
0.8
Kidneyb
2.0
7.7
51.0
1.8
2.1
7.2
1.6
6.0
3.8
1.8
aDry weight.
Fresh weight.
cAlfalfa.
As an indicator of fallout from emissions from a single source, soil concen-
tration should be the most accurate for long-range appraisal. Vegetation and
animals should also reflect the fallout pattern. The soil concentrations of both
lead and cadmium decrease in all directions from the ASARCO smelter stack.
Topography and leaching would be two factors that might alter this pattern at
Effects of Air Pollution on Indigenous Animals and Vegetation 101
-------
some sites. For instance, soil taken from site 37 in September of 1968 and
placed in frames at the University of Montana Botany Department gardens was
assayed in October 1969 and compared with concentrations in soil taken
directly from the East Helena site in October 1969. The transported soil had
been watered routinely in the garden plot during the year. Lead and cadmium
levels both had dropped during the year in Missoula, showing that irrigation and
normal leaching can remove a substantial portion of soil levels of lead and
cadmium.
The concentrations of lead and cadmium in grass also decrease with in-
creasing distance from the stack.
LEAD AND CADMIUM IN GARDEN VEGETABLES
Vegetables, mainly lettuce, were gathered from gardens identified on the
map in Figure 6-2 and analyzed for lead and cadmium. From each of the gardens
from which lettuce was obtained, soil was taken for analyses for lead and
cadmium. A comparison of metal contents of soil and of lettuce growing in that
soil is shown in Table 6-4.
HELENA
7
\ &
\
\
"-* 36«
«v
Mill)
| 30*1 1 31*1 «32
/ ^^ 29*
/ \40*
/ \
N, /}
V(~\
] \ 37i
/ 1
•
uj
^3
Z
>
<
•a:
z
«r
3
/ A
33^ l\
«\
STATION LOCATION
1 M- V JOHNSON RESIDENCE
5 KLEFFNER RESIDENCE
7 ARMAGAST RESIDENCE
8 ARLIENT RESIDENCE
29 N J HELFERT RESIDENCE
30 PREBIL RESIDENCE
31 HILTNER RESIDENCE
32 GRANDY RESIDENCE
33 BUFF RESIDENCE
34 MEIHLE RESIDENCE
35 F MILLER RESIDENCE
36 LEV RESIDENCE
37 BESSLER RESIDENCE
40 LANE RESIDENCE
X ASARCO STACK
Figure 6-2. Plant collection sites.
102 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 6-4. LEAD AND CADMIUM CONTENT
OF SOIL AND LETTUCE3
(ppm)
Site No.
1
35
30
34
31
8
7
29
5
33
Missoula
Garden
Johnson
Miller
Prebil
Meihle
Hiltner
Arlient
Armagast
Helfert
Kleffner
Buff
Hughes
garden
Botany
Dale
Faculty
Lead
Soil
90
840
320
1100
550
49
490
1400
370
440
20
20
—
-
Lettuce
<10b
250
16b
<10C
26b
<10b
68
460
26
30
38
12
14
13
Cadmium
Soil
3
18
8
25
9
1
11
31
10
8
<1
<1
—
-
Lettuce
8b
16
13b
12c
7b
8b
4
28
5
5
<1
<1
1.2
<1
aDry weight.
Leaves washed.
GCabbage.
One lettuce and cabbage collection, that of June 28, 1969, was heavily
splattered with soil due to a recent rain. The lettuce and cabbage leaves were
thoroughly washed under cold running water in the lab and dried by blotting
with cheesecloth. The washing and drying procedures were much more thorough
than those customarily done in preparing leafy vegetables for table use; there-
fore, the amount of metal actually eaten would be greater than the analyses
show. The amount of lead and cadmium indicated by the analyses would
represent the amount contained in the tissues rather than that deposited on the
leaf surfaces. A comparison of metal contents of lettuce from gardens, one
collection washed and the other unwashed, appears in Table 6-5.
Effects of Air Pollution on Indigenous Animals and Vegetation 103
-------
Table 6-5. COMPARISON OF WASHED WITH UNWASHED LETTUCE
FROM THE SAME OR NEIGHBORING GARDENS3
(ppm)
Site No.
35,30
7
29
36,32
5
33
Gardens
Miller, Prebil
Armagast
Helfert, N.J.
Lev, Grandy
Kleffner
Buff
Collection numbers
63,53
68, 51b
2,50
67,56
66,57
64,58
Lead
Unwashed
250
68
460
66
26
30
Washed
16
<10
46
20
26
<10
Cadmium
Unwashed
16
4
28
33
5
5
Washed
13
8
17
17
14
12
aDry weight.
bCabbage.
Source of Lead and Cadmium in Garden Vegetables
Soil from some of the gardens was transported to Missoula so that a
comparison could be made between lettuce grown in an atmosphere free of lead
and cadmium and lettuce growing in air containing both metals. The results of
the comparison are listed in Table 6-6. The sparseness and non-uniformity of the
data prevent the assessment of the sources of metals in garden vegetables, i.e.,
whether from absorption of the metals from the soil through the roots or from
the atmosphere through the leaf surfaces.
Table 6-6. HEAVY-METAL CONTENT OF LETTUCE GROWN
IN EAST HELENA AND IN EAST HELENA SOIL
TRANSPORTED TO MISSOULA3
(ppm)
Site No.
5
34
35,37
Location
Kleffner
Meihle
Miller
Bessler
Lead
East Helena
26
10
250
Missoula
9
33
32
Cadmium
East Helena
5
12
10
Missoula
3
8
28
Dry weight.
UPTAKE OF CADMIUM AND LEAD FROM FOOD SOURCES
Twelve rabbits were involved in a feeding study for 6 weeks. The 12 were
divided into three groups of four animals each. Two rabbits shared a cage; thus
two cages were used for each group. Three breeds were used (New Zealand,
Checkered Giant, and California), and all rabbits were within a few days of being
104 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
9 weeks old when the study began. Precautions were taken to avoid contami-
nation of food or water by contact with metal containers. The animals were fed
a commercial rabbit pellet (Ceretana*) in sufficient quantity to ensure good
health. Concrete feeding dishes were used rather than the standard metal bins.
The rabbits were fed pellets each morning and fresh lettuce each evening. It
was assumed that one rabbit would eat approximately half of the food placed in
the two-rabbit cage. The amount fed daily was 86.6 grams of pellets and 100
grams of lettuce per rabbit. The quantity of lettuce fed was limited by the
amount that could be expected to be available throughout the 6 weeks of the
study. Lettuce was harvested weekly and kept in plastic bags in a cooler until
needed.
Two groups of rabbits were fed lettuce thought to have high lead and
cadmium concentrations. One group ate lettuce grown in East Helena gardens,
and the other ate lettuce grown in Missoula on soil brought from East Helena
and put into frames in the University of Montana botanical garden. Lettuce
brought from East Helena was a composite from ten gardens (sites 1,5,7, 29,
30, 31, 32, 33, 35, and 36) (Figure 6-2). Samples of the rabbit pellet and of
lettuce from both sources were analyzed as well as lettuce samples from the
control gardens.
When the rabbits were sacrificed, one kidney and half of each liver was
removed, placed separately in plastic bags, frozen, and forwarded to WARF
Institute. A femur bone from each of the four rabbits being fed lettuce grown in
East Helena was also sent for lead and cadmium analyses. Analyses on all these
tissues were done at WARF as mentioned above. Results of these analyses are
shown in Table 6-7.
The purpose of this study was to determine the accumulation patterns and
differences for lead and cadmium in rabbits in cases where food was the source
of the metals. Using lettuce from three different sources, supposedly repre-
senting different amounts of lead and cadmium, differences in total body
accumulation were expected. Body accumulation was measured by tissue from
the liver, kidney, and bone. Of the three lettuce sources, concentrations of lead
and cadmium would be expected to decrease in this order: (1) East Helena, (2)
Missoula with East Helena soil, and (3) Missoula. Group 1 would be expected to
have accumulated excess metals via soil and air; group 2, via soil only; and group
3, neither.
The data on lead in liver and kidney indicate differences among groups 1,2,
and 3. The lettuce grown in Missoula in East Helena soil produced the highest
accumulation of metals in tissue; the East Helena grown lettuce, the second
highest; and Missoula lettuce, the third highest.
*Mention of a specific company or product does not constitute endorsement by
the Environmental Protection Agency.
Effects of Air Pollution on Indigenous Animals and Vegetation 105
-------
Table 6-7. LEAD AND CADMIUM CONTENTS OF RABBIT TISSUES3
(ppm)
Animal
1
2
3
4
Diet of East Helena Lettuce
Lead
Liver
0.1
0.1
0.2
0.4
Kidney
0.3
0.3
0.4
0.7
Bone
5
16
8
12
Cadmium
Liver
<0.2
<0.2
<0.2
<0.2
Kidney
1
<1
1
1
Bone
<1
<1
<1
<1
Diet of Lettuce Grown in East Helena Soil Transferred to Missoula
Animal
5
6
7
8
Lead
Liver
0.3
0.2
0.1
0.5
Kidney
0.7
0.6
0.3
0.3
Cadmium
Liver
<0.2
<0.2
<0.2
<0.2
Kidney
<1
<1
<1
<1
Diet of Hughes Garden Lettuce, Missoula (Control
Animal
9
10
11
12
Lead
Liver
0.1
0.1
0.1
0.3
Kidney
0.3
0.2
0.3
0.2
Cadmium
Liver
<0.2
<0.2
<0.2
<0.2
Kidney
<1.0
<0.3
<0.5
<0.2
aFresh weight.
Liver levels of cadmium for all three groups were less than 0.2 ppm. In
group 1, three rabbits had kidney levels of 1 ppm, and all rabbits in groups 2 and
3 had less than 1 ppm. In group 3, two rabbits had concentrations of 0.3 and 0.5
ppm, and one had less than 0.2 ppm. The difference in threshold of readings in
the three rabbits of group 3 may be misleading, however, because the readings of
less than 1 ppm for the other rabbits may actually signify concentrations as low
as or lower than the 0.3 and 0.5 values.
It is apparent, therefore, that for the given length of feeding, quantity of
lettuce fed, and concentration of lead and cadmiun in the lettuce, only small
differences in accumulation occurred among the groups, and total accumulation
was insignificant. Since bone lead of groups 2 and 3 was not assayed, direct
comparison of the three groups on this point is impossible and comparison may
be made only with the literature.
The concentration of lead and cadmium in the lettuce was an important
variable. Lettuce from one garden varied in metal concentration from week to
106 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
week; in East Helena, lettuce from the many gardens used as a source of lettuce
for group 1 varied considerably (less than 10 to 460 ppm). Lettuce from Hughes
Garden (control area) in Missoula (group 3) assayed at 38 ppm lead (100 yards
from the Interstate highway), and lettuce grown on East Helena soil transported
to Missoula contained 32 ppm lead. The source of lead in the Hughes Garden
lettuce has not been identified, but insecticide foliar sprays and automobile
exhaust are suspected as likely sources.
A much longer feeding time and increased daily consumption of lettuce by
the group of rabbits would be required to determine if significant accumulation
differences actually exist. Also, lettuce for each group should be obtained from
gardens containing similar concentrations of these two metals.
CONIFER FOLIAGE INVESTIGATIONS
Sulfur and Lead Content
During October 1969, needle collections were taken for chemical analyses
from conifers growing in the East Helena area. All needles emerging in 1968 and
1969 (and some in 1967) were sent to WARF for total sulfur analysis. A few
samples of 1968 and 1969 needles (and one of 1967 needles) were sent for lead
analysis.
Needles emerging from the bud in the spring of 1968 were formed during
the summer of 1967 and remained in a primordial form enclosed by thick
protective bud scales during the winter. During the rapid spring growth of 1968,
the needle primordia enlarged, thrusting aside the protective bud scales. One
year's needles are separated from another by the bud scales left clinging to the
stem. Using this information, the age of a needle may be determined by counting
the rings of terminal bud scale scars from the branch tip to the needle. The
collection sites, tree species, year of needle emergence, and results of analyses
are listed in Table 6-8.
A change in sulfur and lead content occurred during the period 1967 to
1969. Both lead and sulfur levels were greater in 1968 than in 1967; then both
decreased in 1969. In the case of sulfur, the analysis for total sulfur represents
the amounts assimilated into the conifer needle and that which accumulated on
the surface. Due to an increase in the percentage of sulfur in ores smelted and in
production capacity, the emissions of the ASARCO smelter in East Helena
increased during the late summer of 1967. Thus the conifer needles emerging in
May of 1967 had their most vigorous growing period before the increased
smelter emissions. The sulfur level for the 1967 needles can consequently be
considered as arising in large part from the sulfur accumulating upon the needle
surface from the fall of 1967 to the fall of 1969 (a 2-year period). In contrast,
the needles emerging in the spring of 1968 were exposed to high sulfur dioxide
levels during their most active growing stage and, thus, incorporated more sulfur
into their tissues. Surface accumulation of sulfur also occurred subsequently.
Because the 1968 levels of sulfur dioxide had caused damage to vegetation
Effects of Air Pollution on Indigenous Animals and Vegetation 107
-------
Table 6-8. LEAD AND TOTAL SULFUR
IN CONIFER FOLIAGE IN EAST HELENA, 1969a
(ppm)
Collection
site
34
5
35
Species
Pinus ponderosa
Pinus ponderosa
Pinus sylvestris
Pinus sylvestris
P. contorta
P. contorta
Pinus sylvestris
Pinus sylvestris
P. contorta
P. contorta
Picea engelmanni
Picea engelmanni
Abies lasiocarpa
Abies lasiocarpa
Pinus sylvestris
Pinus sylvestris
Pinus sylvestris
Year needle
emerged
1968
1969
1968
1969
1968
1969
1968
1969
1967-68
1969
1967
1969
1968
1969
1967
1968
1969
Total
sulfur
2100
1400
2200
No needles,
3000
2300
1900
4900
1600
4200
2800
5600
1000
2000
2600
1400
Lead
120 (1967-68)
120
100
all dropped
100
110
110
40
125
90
Dry weight.
and brought complaints from East Helena residents, during the spring and
summer of 1969 the smelter operated at reduced levels whenever weather
conditions indicated that damage would be likely from normal operation. As can
be seen, the 1969 sulfur levels are lower than those in 1968; this is due to less
assimilation of sulfur during the active growing period and a shorter time for
surface accumulation.
Sites 34 and 35 are northwest of the ASARCO stack, and site 5 is southeast
of the stack; all three sites are at nearly equal distances from the source. From a
comparison of the 1968 and 1969 data, it appears the exposure to sulfur at these
two locations is not greatly different. There does, however, seem to be a
difference in accumulation among tree species. For instance, Pinus ponderosa
and P. sylvestris do not have levels as high as P. contorta, Picea engelmanni, or
Abies lasiocarpa. Greater numbers of trees would need to be studied to deter-
mine if there is actually a difference in accumulation rate and whether that
difference is caused by physiological differences, or by differences in needle
morphology and spacing.
Lead content appears to follow a different accumulation pattern than
sulfur; there were in general, no differences among 1967, 1968, and 1969 lead
levels. The one exception was the Pinus sylvestris from site 35. The 40, 125, and
90 ppm of lead in 1967, 1968, and 1969 needles, respectively, reflect the
smelter's relative level of emissions during that period. This would suggest that
108 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
the lead assayed was that which was assimilated into the tissues and did not
include lead deposited on the needle surface; if lead were accumulating on the
needle surface, the 1967 needles would be expected to have more than 40 ppm
lead after 2 years of exposure.
Histological Examinations
On July 26, 1968, 3-year-old seedlings of Pinus ponderosa and Pinus
Sylvestris were planted in four locations. Two of the four conifer plots that had
been planted in 1968 had been destroyed. One of those was located at Bessler's
home (800 yards southeast from the ASARCO stack) and the other at Marche's
(1800 yards southwest from the ASARCO stack). Bessler's plot was destroyed
when ASARCO moved Bessler's house off the property and filled and leveled the
ground where the basement had been. The plots at Marche's were destroyed
because they were not watered or maintained. At the Meihle residence (approxi-
mately 700 yards north of the ASARCO stack), three ponderosa pines and three
lodgepole pines were planted in May 1969.
Collections of conifer foliage for histological studies were made at three
locations during October 1969. These locations were at the residences of Miller
(approximately 500 yards northwest of the ASARCO stack), Meihle (700 yards
northeast from the stack), and Kleffner (1800 yards southeast of the stack). At
Miller's house, needles were taken from a 2-foot-high scotch pine tree. At
Meihle's, needles were taken from the ponderosa, lodgepole, and scotch pine
seedlings that had been planted in 1968 and 1969. At Kleffner's house, col-
lections were taken from trees planted in 1968 and also from a damaged alpine
fir and an Engelmann spruce in his front yard.
Selected pine needles from each of the three sites were prepared for
histological studies ^through the paraffin method, and photomicrographs were
taken to depict the disease syndrome manifested in the needle tissues.
The following phenomena were seen in the photographs of needles from
East Helena.
1. The mesophyll cell below the stomatal opening was almost in-
variably destroyed. This cell was either ruptured, collapsed, or
completely disintegrated by the time the thin-walled cells of the
vascular system were undergoing hypertrophy.
2. The chloroplast and nuclei within the mesophyll cells were de-
stroyed, causing the cells to have a granular appearance.
3. The epithelial cells of the resin canals underwent hypertrophy and,
if collapse did not occur, their enlarged cells became thick-walled
and rigid.
4. The inner walls of the endodermal cells collapsed, and the thicker,
outer walls rarely, if ever, collapsed.
Effects of Air Pollution on Indigenous Animals and Vegetation 109
-------
5. The parenchymatous cells of the transfusion tissue, which lie
between the two vascular bundles, underwent tremendous hyper-
trophy and then collapsed, leaving a large area devoid of cells.
6. The albuminous parenchyma cells of the phloem tissue as well as
those from the inactive phloem (the three to five layers from the
xylem cells) underwent hypertrophy and then collapsed.
All of the above disease symptoms manifested by the various cells and
tissues of the conifer needles indicate sulfur dioxide damage in East Helena. The
same symptoms occurred within the tissues of ponderosa pine needles that
underwent controlled fumigation tests with sulfur dioxide.
The disease syndrome is identical to that observed in 1968 in conifer
needles from East Helena. The amount of damage to conifer needles was greatly
reduced during 1969, a reduction that can be attributed to the shutdown of the
ASARCO smelter during the most sensitive growth period of the conifer needles
(June 1969), as well as to the decreased production at this plant until September
1969.
BIBLIOGRAPHY FOR CHAPTER 6
Allison, R. V. and Thomas Whitehead, Jr. Know Fertilizer Materials
Better: Trace Elements in Some Organic Fertilizers. Florida
Grower. Jan. 1943. p. 4.
Axelsson, Bengt and Mangus Piscator. Renal Damage After Prolonged
Exposure to Cadmium. Arch. Environ. Health. 12:360-373. 1966.
Bates, F. Y., D. M. Barnes, and J. M. Higbee. Lead Toxicosis in Mallard
Ducks. Bull. Wildlife Disease Assoc. 4:116-125. 1968.
Cannon, Helen L. and Jessie M. Bowles. Contamination of Vegetation
by Tetraethyl Lead. Science. 137:765-766. 1962.
Carroll, Robert E. The Relationship of Cadmium in the Air to Cardio-
vascular Disease Death Rates. JAMA. 795:177-179. 1966.
Hopkins, Homer and Jacob Eisen. Mineral Elements in Fresh Vegetables
from Different Geographic Areas. Agric. and Food Chem. 7:633-
638.1959.
Hopkins, Homer, E.W. Murphy, and D. P. Smith. Minerals and Prox-
imate Composition of Organ Meats. J. Amer. Dietic. Assoc.
38:344-349. 1961.
Joseph, Glenn H., Jesse W. Stevens, and John R. MacRill. Nutrients in
California Lemons and Oranges. J. Amer. Dietic. Assoc. 38:552-
559. 1961
110 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Klein, A. K. and H. J. Wichmann. Report on Cadmium. Assoc. Official
Agric. Chem. J. 25:257-269.1943.
Krehl, Willard A. and George R. Cowgill. Nutrient Content of Cane and
Beet Sugar Products. Food Res. 20:449. 1955.
Locke, L. N., H. D. Irby, and G. E. Bagley. Histopathology of Mallards
Dosed with Lead and Selected Substitute Shot. Bull. Wildlife
Disease Assoc. 5:143-147. 1967.
Locke, L. N. et al. Lead Poisoning and Aspergillosis in an Andean
Condor. JAVMA. 155:1052-1056. 1969.
McCance, R. A. and E. M. Widdowson. The Composition of Foods.
Medical Research Council SRS 297. Her Majesty's Stationery
Office .London. 1967.
McKee and Wolf. Water Quality Criteria, 2nd Ed. The Resources
Agency of California. State Water Quality Control Board, Sacra-
mento, California, Pub. No. 3-A.
Schroeder, Henry A. Cadmium Hypertension in Rats. Am J. Physiol.
207:62-66.1964.
Schroeder, Henry A. Cadmium as a Factor in Hypertension. J. Chron.
Dis. 75:647-656. 1965.
Schroeder, Henry A. Cadmium, Chromium, and Cardiovascular Disease.
Circulation. 55:570-582. 1967.
Schroeder, Henry A. et al. Hypertension in Rats from Injection of
Cadmium. Arch. Environ. Health. 7J:788-789. 1966.
Schroeder, Henry A. and Jeffrey Buckman. Cadmium Hypertension: Its
Reversal in Rats by a Zinc Chelate. Arch. Environ. Health.
14:693-697. 1967.
Schroeder, Henry A. et al. Influence of Cadmiun on Renal Ischemic
Hypertension in Rats. Amer. Jour. Physiology. 274:469-474. 1968.
Schroeder, Henry A. et al. Action of a Chelate of Zinc on Trace Metals
in Hypertensive Rats. Amer. Jour. Physiology. 274:796-800. 1968.
Smith, J. P. and A. J. McCall. Chronic Poisoning from Cadmium Fume.
J. Path. Bact. 50:287-296. 1960.
Von Oettingen, W. F. Poisoning: A Guide to Clinical Diagnosis and
Treatment. W. B. Saunders Co..Philadelphia. 1958.
Warren, Harry V. Some Aspects of Lead Poisoning in Perspective. J.
Coll. Gen.Practit. 77:135-142. 1966.
Effects of Air Pollution on Indigenous Animals and Vegetation 111
-------
Warren, Henry V. and Robert E. Delavault. Observations on the Bio-
geochemistry of Lead in Canada. Transactions of the Royal Society
of Canada. 54:11-20. 1960.
Warren, Henry V. and Robert E. Delavault. A Geologist Looks at
Pollution: Mineral Variety. Western Miner. Dec. 1967.
Warren, Henry V. and Robert E. Delavault. Lead in Vegetables. Repro-
duction of a letter to the Editor published in the Lancet, p. 1252.
June 8,1968.
112 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
7. EFFECTS OF AIR POLLUTION ON
LIVESTOCK AND ANIMAL PRODUCTS
Trent R. Lewis, Ph.D.
ENVIRONMENTAL PROTECTION AGENCY
National Environmental Research Center
This study was conducted to assess the effects of air pollution on livestock
and consumable products derived from livestock. Two questions were of
significance: (1) what was the primary effect of air pollution on the health of
the livestock per se? and (2) what was the health hazard to humans who ingested
meat, milk, and eggs from such farm animals?
EFFECTS ON LIVESTOCK
Interviews with farmers, veterinarians, and the Montana Livestock Sanitary
Board revealed that horses were markedly more susceptible than other species of
farm animals to environmental toxicants in the Helena Valley. As a result,
portions of the manes of 39 horses were clipped at 13 farm sites for future
quantification of their lead, cadmium, zinc, and arsenic contents. Hair is a depot
for lead, cadmium, and arsenic during long-term exposure to these toxicants.
Because hair and other epidermal structures normally have a high zinc content,
they are less reliable
-------
One person stood at the head of each horse and controlled the horse while
the second person took two to three handfuls of mane and cut each handful
with heavy scissors. These samples, which weighed between 6 and 20 grams,
were placed in plastic bags; the bag was tied off, and an identification tag
containing relevant comments was attached to each.
Animal products were collected at five sites in East Helena where chickens
or lactating dairy cows were housed or, in one case, where home slaughtering
had occurred. In addition, a rabbit that had been dead for approximately 1 to 2
hours and showed no evidence of accidental or predatory cause of death was
collected for examination.
Sample Preparation
Two- to six-gram samples of horse hair were weighed and cleaned. Cleaning
entailed successive washings with acetone, ethyl ether, and acetone. Time of
contact was 10 to 15 minutes for each washing, accompanied by agitation from
time to time by hand or stirring rod. After the last acetone wash was decanted,
about 150 milliliters (ml) of a 0.75 percent commercial detergent solution was
added. Time of contact was about 15 minutes, also with stirring. Then the hair
was washed free of detergent with tap water, placed on filter paper, and rinsed
four times with deionized distilled water, and then with acetone. The hair was
dried for 2 to 4 hours at 90° to 100° C and then weighed.
Digestion
Hair samples were placed in digestion flasks and heated gently on a hot
plate. Portions of redistilled nitric acid were added, beginning with 10 ml and
decreasing as the digest decreased in volume and the temperature increased.
When the digest was yellow, 1 to 2 ml of nitric acid and 0.5 ml of 70 percent
perchloric acid were added to complete digestion. The acid mixture was evap-
orated off until the flask was just moist. When cool, the residue was taken up in
water and about 0.5 ml of concentrated redistilled nitric acid was added. Final
volume in all cases was 25.0 ml.
Analysis for Lead
In general, 10-ml aliquots were taken for analysis by chelation extraction
and solvent concentration. Dilutions of samples of 30 ml volume were adjusted
to a pH of 2.28 to 2.34. One milliliter of 1 percent chelating agent, ammonium
pyrrolidine dithiocarbamate, was added to a 60 ml separatory funnel, and the
sample solution was poured in. A quantity of 5.0 ml of solvent, methyl isobutyl
ketone, was pipetted in and each flask was shaken for 2 minutes. After about 5
minutes, the lower aqueous phase was discarded, and solvent was collected for
centrifugation at 2500 rpm for 10 minutes. The solvent was aspirated into the
atomic absorption apparatus, and lead concentration was determined by com-
parison of absorption with similar lead standards.
114 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Analyses for Other Elements
One milliliter was taken of the 25 ml of acid digest and diluted to bring the
zinc concentration to between 1 and 2 micrograms per milliliter. On most
samples, 1 ml of sample was added to 20 ml of water. Sample dilutions were
aspirated directly into the atomic absorption spectrophotometer, and absorption
of samples was compared with standards in aqueous solution. Aliquots of the
previous acid sample digest were analyzed by atomic absorption spectro-
photometry for cadmium and arsenic in the same manner as described for lead
and zinc.
Results
A geographic orientation of the sampling sites is presented in Table 7-1. This
orientation is based upon an angular displacement from the north-south me-
ridian passing through the smoke stack of the American Smelting and Refining
Company at East Helena, Montana. Angular measurements are clockwise,
originating at the north and increasing to east, south, and west, and returning to
Table 7-1. COLLECTION SITES
FOR HORSE MANE SAMPLES
Site
1
2
3
4
5
6
7
8
9
10a
10b
11
12
Compass
Direction
SSE
E
SE
SE
NE
NNW
NNW
N
NW
WNW
WNW
W
E
Degrees
160
85
110
122
30
338
344
355
330
285
286
278
95
Distance from stack, mi
1.0
2.9
2.6
5.3
2.9
2.3
1.9
1.0
1.4
2.3
7.6
3.0
4.7
north. Distances from the stack are also recorded. Arsenic, zinc, cadmium, and
lead concentrations in the manes of the 39 horses sampled are found in Table
7-2. Duplicate analyses and their means are presented for each of the four
elements, and a site mean has also been computed. Since the sensitivity of the
assay method (atomic absorption) used to determine arsenic content was 2.0
Mg/g, sample duplicates and mean values of the elements are difficult to com-
pare. Detection of measurable arsenic is merely indicative of exposure to arsenic;
toxicity can be determined only on the basis of absolute levels.
Effects of Air Pollution on Livestock and Animal Products
115
-------
Table 7-2. ANALYSES FOR ARSENIC, ZINC, CADMIUM,
AND LEAD IN HORSE-MANE HAIR
Site
1
1
1
2
2
2
2
2
2
2
2
2
2
2
3
3
4
Horse
Brown stallion
Black and white
Welsh mare
Palomino gelding
Bay gelding
Bay mare
Bay mare3
Palomino mare
Bay mare
Bay mare
Bay mare
Shetland gelding
Bay gelding
Sorrel gelding
Black gelding
Sorrel gelding
Bay mare
Bay gelding
Arsenic
Sample
6.5
5.3
7.5
3.7
2.1
0
0
0
4.4
0
0
3.1
0
0
0
0
0
0
0
0
0
0
Avg
5.9
5.6
1.0
4.2
2.2
1.6
0.34
0
Zinc
Sample
230
210
220
220
240
240
210
200
210
260
280
220
240
240
210
250
300
350
430
420
230
210
300
380
370
400
210
190
250
230
380
340
180
170
Avg
220
220
240
230
200
240
250
240
230
320
420
220
340
380
200
280
240
360
300
170
Cadmium
Sample
2.3
2.7
1.9
2.3
3.6
1.8
1.8
2.2
0.8
0.6
1.0
0.9
2.0
1.6
1.7
1.7
1.1
1.2
1.7
1.6
1.3
1.8
1.4
1.5
1.0
1.1
0.6
2.3
1.8
1.5
4.6
3.6
0.9
1.0
Avg
2.5
2.1
2.7
2.4
2.0
0.7
1.0
1.8
1.7
1.2
1.6
1.6
1.4
1.0
1.4
1.4
1.6
4.1
2.8
1.0
Lead
Sample
4.2
7.2
11.2
13.8
6.6
5.3
4.3
4.6
2.0
2.6
4.5
3.0
15.6
12.1
4.6
3.0
4.9
3.4
4.6
5.2
3.1
4.1
4.8
2.8
5.5
3.9
8.0
6.7
9.8
14.8
25.8
22.2
9.0
6.7
Avg
5.7
12.5
6.0
~87T
4.4
2.3
3.8
13.8
3.8
4.2
4.9
3.6
3.8
4.7
7.4
"57
12.3
24.0
T51
7.8
116 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 7-2 (continued). ANALYSES FOR ARSENIC, ZINC, CADMIUM,
AND LEAD IN HORSE-MANE HAIR
Site
4
4
4
4
5
6
6
6
6
7
8
8
8
9
9
Horse
Appaloosa mare
Shetland pony
Black gelding
Bay gelding
Bay mare
Bay gelding
Black gelding
Brown gelding
Buckskin gelding
Bay gelding
Sorrel mare
Bay mare
Bay mare
Roan mare
Sorrel gelding
Arsenic
Sample
0
0
2.3
0
0
0
0
0
0
0
0
4.5
0
0
3.2
0
0
0
Avg
1.1
-03-
-Q-
~o~
~o~
2.3
1.6
T3~
0
Zinc
Sample
170
200
190
190
200
200
200
180
220
190
180
190
180
230
140
190
180
190
200
190
210
220
240
260
230
210
200
180
200
200
250
210
Avg
180
190
200
190
190
200
200
200
160
190
200
190
210
220
250
220
190
220
200
230
220
.Cadmium
Sample
0.8
0.7
2.4
1.9
0.6
0.7
0.5
0.5
8.4
9.6
0.3
0.3
0.2
0.3
0.3
0.3
0.6
0.3
1.3
1.4
2.3
2.2
1.7
2.6
3.0
1.3
1.5
1.5
2.8
3.0
Avg
0.8
2.1
0.7
0.5
TO"
9.0
0.3
0.2
0.3
0.4
"03"
1.4
2.3
2.2
2.2
2.2
1.5
2.9
Lead
Sample
5.5
4.3
10.6
11.9
4.4
3.4
7.0
5.5
32.6
37.6
0.8
1.6
0.7
0.9
1.1
2.5
1.7
1.8
11.1
9.6
9.8
9.8
8.0
5.3
6.4
5.1
13.8
15.6
6.1
11.9
Avg
4.9
11.2
3.9
6.3
6.8
35.1
35.1
1.2
0.8
1.8
1.8
1.4
10.4
"104
9.8
6.6
5.8
7.4
14.7
9.0
TT8
Effects of Air Pollution on Livestock and Animal Products
117
-------
Table 7-2 (continued). ANALYSES FOR ARSENIC, ZINC, CADMIUM,
AND LEAD IN HORSE-MANE HAIR
Site
10a
10b
10b
11
11
11
12
Horse
Bay gelding
Chestnut sorrel
Black and white
mare
Sorrell gelding
Bay gelding
Palomino pony
Bay mare
Arsenic
Sample
0
0
0
0
0
0
0
Avg
0
0
~CT
~"0~
Zinc
Sample
190
210
250
240
220
220
240
230
200
200
200
220
220
210
Avg
200
200
240
220
230
240
200
210
220
220
220
Cadmium
Sample
0.7
0.9
1.4
1.1
1.5
1.4
0.7
0.6
1.4
1.3
0.9
5.3
1.1
0.8
Avg
0.8
"08"
1.2
1.4
1.3
0.7
1.4
3.1
1.7
1.0
1.0
Lead
Sample
3.9
2.8
9.5
6.3
6.9
5.4
3.0
2.8
5.1
4.8
5.8
3.0
3.5
2.8
Avg
3.4
~3T
7.9
6.2
~7J5
2.9
5.0
4.4
~TT
3.2
^2
aDied October 12, 1969.
One method of biological evaluation would be to compare data found in
Tables 7-1, 7-2, and 7-3. Table 7-3 ranks the sites of collection from the highest
to lowest concentration of each element within the mane. Such a comparison
reveals that horses located at sites 1,3,5,7,8, and 9 (sites near the smelter) had
high cadmium and lead concentrations. The single horse that represented site 5
had twice the lead concentration of any other horse in the study. Four of the six
sites are within 2 miles of the smelter stack, and the other two are within 3
miles. Prevailing summer daytime winds at sites 1 and 3 are west to east. Sites 5,
7, 8, and 9 are located in areas where the prevailing summer nightime winds
blow from south to north. Cadmium and lead levels in soil and vegetation
samples were high at five of the six sites; the exception was site 5. The extremely
high cadmium and lead levels in the mane from the horse at site 5 probably
reflect husbandry practices in which the animal depended primarily on sparse
pasture for food.
Horses at site 6 are unique in that they are never permitted to graze pasture,
but are fed hay shipped in from a location outside the Helena Valley. Further-
more, these horses are stabled 2.3 miles from the smelter, a shorter distance
from the smelter than sites 3 and 5. These animals were selected as the local
control population for comparison with horses at other sites and under different
118 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 7-3. RANKING OF SITES BY AVERAGE METAL CONTENT
OF HORSE MANE
Arsenic
Site
1
8
2
4
3
5
6
7
9
10a
10b
11
12
Content,
M9/9
4.2
3.9
0.3
0.3
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Cadmium
Site
5
3
i
9
8
11
2
7
10b
12
4
I0a
6
Content,
iug/g
9.0
2.9
2.4
2.2
2.2
1.7
1.4
1.3
1.3
1.0
1.0
0.8
0.3
Zinc
Site
3
2
10b
1
8
9
12
11
7
5
10a
4
6
Content,
A
-------
Table 7-4. FIELD NOTES ON HORSES SAMPLED
Site
1
1
1
2
2
2
2
2
2
2
2
2
2
2
3
3
4
4
4
4
4
5
6
6
6
6
7
8
Horse
Brown stallion
Black and white
Welch mare
Palomino gelding
Bay gelding
Bay mare
Bay marer
Palomino mare
Bay mare
Bay mare
Bay mare
Shetland gelding
Bay gelding
Sorrel gelding
Black gelding
Sorrel gelding
Bay mare
Bay gelding
Appaloosa
Shetland pony
Black gelding
Bay gelding
Bay mare
Bay gelding
Black gelding
Brown gelding
Buckskin gelding
Bay gelding
Sorrel mare
Mane color
Light brown
Black
Yellow
Black
Black
Black
Yellow
Black
Black
Black
Black
Black
Black, gray-
brown mixed
together
Black
Brown
Black
Black
Black
Gray
Black and
gray
Dark brown
Black
Black
Black
Black
Brown
Brown
Brown
Age,
yr
2
15
4
12
4
3
34
5
10
30
11
9
8
11
20
20
8
3
6
5
18
1.5
10
7
12
28
15
20
Time at
site,3 yr
1
6
1
12
4
3
2
5
10
17
2
5
5
11
15
7
5
3 mo
4
3 mo
10
1.5
3
2
3
16
5
Comments
Hay from outside;
slight grazing
Sick last 6 mo;
worse last 2 mo
13 yr in hills this
side of mountains
Wind problems
3 yr at fairground
2 yr SE of here in
mountain
At Billings before
here. Owner says
horse is smoked.
In mountains 15 miles
east of smelter most
of time. Had since
was a colt.
120 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 7-4 (continued). FIELD NOTES ON HORSES SAMPLED
Site
8
8
g
9
10a
10b
10b
11
11
11
12
Horse
Bay mare
Bay mare
Roan mare
Sorrel gelding
Bay gelding
Sorrel gelding
Black and
white mare
Sorrel gelding
Bay gelding
Palomino pony
Bay mare
Mane color
Black
Black
Brown
Brown
Black
Black
Black
Brown
Black
White
Black
Age,
yr
12
3
7-8
17-20
7
6-8
10
7
7
1
15
Time at
site,3 yr
5
5-6
5-6
7
7
10
1 mo
1 mo
2-3 mo
15
Comments
Here in summer, out
in winter. Purchased
in 1964.
Always in corral, eats
home-grown hay
Stifled.
In pasture off main
road.
Eats hay from Site 8.
Born and raised on
premises.
aYears unless indicated otherwise.
bDied October 12, 1969.
One animal merits special attention because it was sick during the period of
sample collection and died shortly thereafter. This animal was a 3-year-old bay
mare that had lived at site 2 for its entire lifespan. The owner stated that the
animal had been sick for approximately 6 months and became noticeably
dyspneic during the last 2 months preceding death. Table 7-5 summarizes
elemental analyses performed on specific organs by the Montana Livestock
Sanitary Board (MLSB), FDA laboratory in Denver, Colorado, and NAPCA
personnel in Cincinnati, Ohio.
The postmortem report prepared by the local veterinarian read:
10/12 - about 4 pm on horse reported to have clinical signs of
"smoked" horse syndrome. Frothy nasal exudata, congestion and con-
solidation in lungs with varying degrees of hepatization, grossly; not the
severity of lung damage as seen in some previous cases on ranch. All
other systems (no nervous exam) appeared grossly normal.
Effects of Air Pollution on Livestock and Animal Products
121
-------
Table 7-5. POSTMORTEM ORGAN ANALYSES OF HORSE, SITE 2a
(M9/g)
Organ
Lung
Liver
Kidney
Flank muscle
Mane hair
Heart
Spleen
Bone
As
0.7
0
0.1
Negative
Trace
0
0.11
2.0
0
0
0
Pb
0.3
0.4
5.0
4.0
4.0
2.4
0.08
3.8
2.0
0.3
66.5
Cd
1.6
0.6
80.0
410.0
228.0
3.9
1.0
0.4
4.1
1.0
Zn
14.0
56.0
135.0
142.0
85.0
68.3
240.0
6.5
36.0
65.0
Authority
FDA
NAPCA
FDA
MLSB
FDA
NAPCA
FDA
NAPCA
NAPCA
NAPCA
NAPCA
aWet weight.
Conclusions
Proximity to the stacks of the American Smelting and Refining Company
and the Anaconda Company correlates with increased levels of arsenic, lead, and
cadmium in the manes of horses. Such findings are consistent with the results of
soil and vegetation analyses for the area. Furthermore, older animals, animals
residing in the Valley for the longest duration, and chronically impaired animals
had high concentrations of lead and cadmium in their manes. On the other hand,
horses that had no access to pastures for grazing had the lowest concentrations
of lead and cadmium in their manes. Control horses from site 6 had no
detectable arsenic, 1.4 jitg of lead/g, 0.3 /ug of cadmium/g, and 190 /ug of zinc/g.
No baseline values for these elements in horsehair could be found in the existing
literature. In reviewing the elemental content of the manes of these horses,
however, 50 percent of the horses at sites investigated showed lead and cadmium
levels two to five times greater than the values found in the control horses.
The arsenic levels that were detected are indicative of exposure to arsenic;
however, the toxicologic significance of these levels remains unclear. Arsenic
concentrations tend to increase with increasing zinc, cadmium, and lead levels in
hair. Zinc is considered to be a metal with minimal toxic properties; zinc
poisoning in animals is a very controversial subject because of the variable results
in experimental studies. The range of levels of zinc in the manes of horses in this
study does not appear to suggest exposure to toxic levels.
The horse from which postmortem data are presented had highly toxic
levels of cadmium and lead in the kidney and liver; these levels were not
reflected in the mane. This disparity probably relates to an acute exposure to
these metals rather than a long-term or chronic exposure. The level of 4 /ug of
lead per gram of liver tissue reflects lead poisoning, the normal concentration
122 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
being 0.04 ^g/g. The postmortem report on the lung is consistent with chronic
lead and/or cadmium exposure, pneumonia primary or secondary to heavy-metal
exposure, and/or heart disease primary or secondary to heavy-metal exposure.
CONTAMINATION OF LIVESTOCK PRODUCTS
In conjunction with the Denver laboratory of the Food and Drug
Administration, a protocol was evolved to assess the health hazards to humans of
foodstuffs derived from the indigenous animal population. This protocol sought
the collection of the following four types of biological samples:
1. Samples, 50 to 100 grams each, of kidney, liver, and muscle
collected from 10 beef cattle and 10 swine from each of the four
compass points relative to the American Smelting and Refining
Company smelter; preferably all samples for each point were to be
within a 1-mile radius of each other and between 0 and 5 miles
from the smelter.
2. One mile sample, 50 cubic centimeters, from each lactating dairy
cow that could be found in the East Helena area, up to a maximum
of 10 samples.
3. Egg samples from chickens in the East Helena area, up to a
maximum of 10 egg samples from 10 different sites.
4. Kidney, liver, and muscle samples, 50 grams, from any seriously
sick domestic or wild animal in the East Helena area.
The domestic animal population in the East Helena area is small, not
uniformly distributed, and migratory in nature. The majority of the animals,
notably beef cattle and horses, are in the distant mountain pastures in the
summer months and proximate to the ranches during the winter. Collection of
the aforementioned samples was complicated further when the opening of the
local slaughter house was delayed from October 1969 to January 1970. Thus, all
potentially edible foodstuffs of animal origin were limited to those that could be
collected from local farms either as egg or milk samples or to those that could be
obtained immediately following home slaughtering. Unfortunately, these
samples amounted to chicken, rabbit, milk, beef, and pork samples from five
different farm sites. The sampling locations and results are presented in Table
7-6. The angular degrees and distances from the stack are computed in the same
manner as for Table 7-1.
Samples were analyzed for all metals except arsenic by the FDA laboratory
in Denver, Colorado, using procedures of wet ashing and atomic absorption
spectrophotometry. Samples to be analyzed for arsenic were ashed in a muffle
furnace at 550° C for 2.5 hours and quantitated by arsine distillation into silver
diethyldithiocarbattiate. The resulting complex was measured spectrophoto-
metrically at 540 nanometers.
Effects of Air Pollution on Livestock and Animal Products 123
-------
Table 7-6. SELECTED METAL CONTENTS
OF MISCELLANEOUS ANIMAL PRODUCTS3
Specimen
Chicken (muscle)
Rabbit (muscle)
Whole milk
Beef tissue (liver)
Beef tissue (muscle)
Beef (knee bone)
Swine tissue (heart)
Sausage
Distance from stack,
degrees
327
112
287
197
197
133
197
197
miles
1.1
0.4
1.8
1.9
1.9
0.6
1.9
1.9
As
Trace
0.6
Trace
0.2
0.05
0
Trace
Trace
Pb
0.1
0.5
0.06
0.2
0.4
20.0
0.1
0.1
Cd
0.06
0.2
0.02
0.2
0.4
1.4
0.1
0.1
Zn
5.5
12.0
4.9
69.5
27.0
58.0
19.0
18.0
aWet weight.
124 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
8. TRACE-METAL CONCENTRATIONS
IN HUMAN HAIR
D. I. Hammer, M.D., J. F. Finklea, M.D.,
R. H. Hendricks, Ph.D., C. M. Shy, M.D.,
andR. J. N. Norton, M.D.
ENVIRONMENTAL PROTECTION AGENCY
National Environmental Research Center
BACKGROUND AND INTRODUCTION
Human scalp hair was collected to determine whether the content of three
trace metals, lead (Pb), cadmium (Cd), and arsenic (As), reflected environmental
concentrations in East Helena, Helena, and Bozeman, Montana. These cities
represented an exposure gradient for Pb, Cd, and As as follows: East Helena >
Helena > Bozeman. The explicit hypothesis to be tested was that mean hair
concentrations of Pb, Cd, and As would reflect this exposure gradient and would
differ significantly between cities at the p < 0.05 level when tested by a one-way
analysis of variance. Logarithmic transformations of trace-metal data, often
appropriate, were used in this study.
MATERIALS AND METHODS
The study population consisted of fourth-grade school boys who had lived
in the specified city for 3 or more years. Possible confounding effects of age,
sex, and hair color were controlled and the effects of dyes and hair sprays were
minimized by the study design. With the cooperation of the local school boards,
explanatory letters and consent forms were sent to parents of eligible children.
Volunteer response was 68 percent (25 of 37) in East Helena, 54 percent (21 of
39) in Helena, and 84 percent (38 of 45) in Bozeman.
Instruction sheets for collection of hair and use of plastic vials were sent
home with all volunteers. Virtually all of the samples were collected during the
last 2 weeks of October 1969.
Trace-metal analyses were performed by the Western Area Occupational
Health Laboratory. The samples were numbered in a random fashion and sent to
the laboratory. The hair was carefully washed free of adhering materials in
detergent, distilled water, alcohol, and hot EDTA (ethylenediaminotetraacetic
acid). Then the hair was dried, weighed, and digested in acid prior to chemical
analysis. Pb, Cd, Zn, and Cu were measured by atomic absorption spectro-
photometry; arsenic was analyzed by a colorimetric method.
125
-------
RESULTS
All volunteers cooperated willingly. Specimen collection was painless and
required minimal inconvenience for the participants because this tissue is
normally discarded periodically anyway. All data are expressed in jug/g (parts per
million). Both original and log-transformed distributions for each city are
presented in Tables 8-1 through 8-10. As expected, Pb, Cd, and As distributions
were skewed and Zn was not. The Cu distribution, however, was skewed only for
Helena and Bozeman.
Table 8-1. DISTRIBUTION OF ARITHMETIC MEAN HAIR LEAD LEVELS
BY CITY
Concentration range, /ug/g
0 to 24 9
25 to 49 9
50 to 74 9
75 to 99 9
1 00 to 1 24 9
125 to 149 9
150 to 174 9
175 to 199 . . . . . .
200 to 299
300 to 399
400 to 499
500 to 599
Statistic
X
Median
s
s2
n .
East Helena
13
3
4
1
2
1
1
44 3
20
49 3
2432 92
25
Helena
20
1
12 1
7 9
11 4
130 9
21
Bozeman
38
7 6
6 5
5 0
25 0
38
126 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 8-2. DISTRIBUTION OF ARITHMETIC MEAN
HAIR CADMIUM LEVELS BY CITY
Concentration range, /ug/g
<1
1
2
3
4
5
6
7
8
9
1 0 to 1 4
15 to 29
30 to 34
Statistic
j<
Median
s
s2
n
East Helena
10
4
5
4
1
1
_
_
_
_
2.0
1.6
1.54
2.39
25
Helena
12
6
1
1
1
_
_
_
1.3
0.9
1.30
1.70
21
Bozeman
25
10
1
1
_
_
_
_
_
_
0.9
0.8
0.58
0.34
37
Table 8-3. DISTRIBUTION OF ARITHMETIC MEAN HAIR ARSENIC
LEVELS BY CITY
Concentration range, /xg/g
<1
1
2
3
4
5
6
7
8
9
10to14
15 to 19
20 to 39
Statistic
3< . . . .
Median
s
s2
n
East Helena
2
2
1
2
4
1
1
2
_
1
5.2
4.0
6.0
36.2
16
Helena
10
3
_
_
0.84
0.7
0.33
0.11
13
Bozeman
27
1
_
_
_
0.44
0.4
0.27
0.07
28
Trace-Metal Concentrations in Human Hair
127
-------
Table 8-4. DISTRIBUTION OF ARITHMETIC MEAN HAIR ZINC LEVELS
BY CITY
Concentration range, /ug/g
0 to 49
50 to 74
75 to 99 .
1 00 to 1 24
125 to 149
150 to 174
175 to 199
200 to 224
225 to 249 ....
250 to 275
Statistic
x
Median
s . . .
s2
n
East Helena
_
6
7
7
4
1
145.2
145
30.8
953.0
25
Helena
_
2
3
2
9
1
4
155.4
160
36.9
1362.2
21
Bozeman
_
5
13
11
7
1
1
154.2
155
32.5
1061.5
38
Table 8-5. DISTRIBUTION OF ARITHMETIC MEAN
HAIR COPPER LEVELS BY CITY
Concentration range, /ug/g
<10 ...
1 1 to 20
21 to 30
31 to 40
41 to 50
51 to 60
61 to 70
7 1 to 80 ....
81 to 90
91 to 100
101 to 110
> 111
Statistic
"x
Median
s
s2
n
East Helena
7
18
-
-
11.8
11
3.0
9.3
25
Helena
9
10
1
1
-
12.6
11
6.0
36.45
21
Bozeman
15
14
3
1
1
1
1
1
22.5
11
34.7
1208.8
37
128 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 8-6. DISTRIBUTION OF HAIR LEAD LEVELS BY CITY
(loge)
Concentration range, jiig/g
0 to 0.99
1 .0 to 1 .99
2.0 to 2.99
3.0 to 3.99
4 0 to 4 99
5 0 to 5 99
6 0 to 6 99
Statistic
><
Antilog 3<
s2
n
East Helena
7
6
3
8
1
3.1
22.3
1.27
1.63
25
Helena
1
9
7
4
_
_
2.1
8.9
0.74
0.55
21
Bozeman
4
19
14
1
_
1.8
6.1
0.68
0.47
38
Table 8-7. DISTRIBUTION OF HAIR CADMIUM LEVELS BY CITY
dogj
Concentration range, /ug/g
-1.99 to -1.0
-0.99 to -0.01
0 to 0.99
1.0 to 1 .99
2.0 to 2.99
3.0 to 3.99
Statistic
x
Antilog x
s
s2
n
East Helena
10
7
8
0.41
1.5
0.78
0.62
25
Helena
12
6
3
0.04
1.0
0.67
0.45
21
Bozeman
3
22
11
1
-0.25
0.77
0.60
0.36
37
Trace-Metal Concentrations in Human Hair
129
-------
Table 8-8. DISTRIBUTION OF HAIR ARSENIC LEVELS BY CITY
(logj
Concentration range, jug/g
-2 99 to -2 0
- 1 99 to - 1 0
-099 to -001 . .
0 to 0.99
10 to 1.99
2.0 to 2.99
3.0 to 3.99
Statistic
><
Antilog x
s
s2
n ... .
East Helena
1
1
3
7
3
1
1.1
30
1.2
1.6
16
Helena
1
9
3
_
_
-0.34
0.70
0.46
0.21
13
Bozeman
5
8
14
1
_
_
-1.0
0.36
0.71
0.50
28
Table 8-9. DISTRIBUTION OF HAIR ZINC LEVELS BY CITY
(loge)
Concentration range, /ug/g
4 0 to 4.9
5 0 to 5 9
Statistic
><
Antilog x^
s
s2
n
East Helena
13
12
49
141 9
0 22
004
25
Helena
7
14
5.0
149 9
025
006
21
Bozeman
18
20
5.0
149 9
020
0 04
38
130 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 8-10. DISTRIBUTION OF HAIR COPPER LEVELS BY CITY
(loge)
Concentration range, M9/9
1 .0 to 1 .99
2.0 to 2.99
3.0 to 3.99
4.0 to 4.99
5.0 to 5.99
Statistic
x
Antilog ><
s
s2
n
East Helena
1
24
2.3
104
054
0.30
25
Helena
2
17
2
24
11 5
040
0 16
21
Bozeman
1
28
5
2
1
2 6
14 4
0 76
0 57
37
A summary of hair trace-metal mean concentrations among cities is shown
in Table 8-11. Pb, Cd, and As means were highest in the most polluted
community, East Helena; were intermediate in Helena; and were lowest in the
least polluted community, Bozeman. These differences for each pollutant were
tested by a one-way analysis of variance on the original and on log-transformed
data. A summary of the F ratios and their respective probabilities are shown in
Table 8-12. Thus, the means for Pb, Cd, and As rank according to the hypothesis
and the differences among them are significant. Moreover, the differences among
the respective means for Zn and Cu, as postulated, are not significant.
Table 8-11. SUMMARY OF ARITHMETIC MEAN CONCENTRATIONS
OF TRACE METALS
IN EAST HELENA, HELENA, AND BOZEMAN, MONTANA
(ppm)
Metal
Pb
Cd
As
Zn
Cu
East Helena
43.1
2.0
5.2
145.2
11.8
Helena
12.1
1.3
0.84
155.4
15.1
Bozeman
7.6
0.9
0.41
154.2
22.5
Trace-Metal Concentrations in Human Hair
131
-------
Table 8-12. F RATIOS3 OF TRACE-METAL CONCENTRATIONS
IN EAST HELENA, HELENA, AND BOZEMAN, MONTANA
Arithmetic mean
Metal
Pb
Cd
As
Zn
Cu
F ratio
14.32
4.98
12.96
0.72
1.53
Probability
p < 0.005
0.01 >p> 0.005
p < 0.005
0.5>p>0.25
0.25>p>0.10
Loge
Metal
Pb
Cd
As
Zn
Cu
F ratio
15.14
7.93
30.27
0.68
1.77
Probability
p < 0.005
p < 0.005
p < 0.005
0.5>p>0.25
0.25>p>0.10
One-way analysis of variance.
DISCUSSION
Determinations of trace metals in hair measure exogenous and endogenous
deposition. The former reflects metal resulting from external contamination by
substances such as dyes, shampoos, hair tonics, sweat, and dust; the latter
reflects metal deposited in hair directly or indirectly through the blood stream.
For example, in cities with relatively high levels of Pb in the ambient air,
external contamination of the hair probably occurs. The pre-analysis hair wash
included detergent and EDTA, both of which are known to remove large
amounts of the metals analyzed. Thus, most or all of the superficially bound
trace metals were removed from the hair before analysis. Not unreasonably, the
mean levels of Cu, Zn, and Cd in all cities and Pb and As in Bozeman and Helena
are lower than indicated in previously published studies in which hair was
washed only with distilled water, which removed less exogenous contamination.
We do not know how long it takes for a metal placed on the hair — lead dust, for
example — to attach to the hair chemically; nor do we know the exact nature
and extent of this bonding.
In addition, we do not know how well hair levels reflect the body burden of
a metal. In humans, however, As can be found in the hair root several hours after
feeding, and in rats, Cd concentrations in hair are proportional to the Cd in the
diet. Comparable studies are not yet available for Pb. The extent to which hair
levels of these metals correlate with teeth and bone levels has not been deter-
mined.
If these elevated levels do reflect an increased body burden (or at least
increased absorption), the relative contributions of gastrointestinal and respira-
tory absorption routes are not known. The bulk of Pb intake is dietary, but a
higher proportion of respired than ingested Pb is absorbed. Absorption by each
route is affected by many factors and this study could not clarify their respec-
tive roles. This problem should be given further consideration, however.
Finally, a substantial portion of the levels of hair Pb observed in this study
were as high as those found elsewhere in conjunction with illness. In other
132 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
studies, the children were all much younger and often symptomatic. Also, the
range of hair lead levels in all studies is quite large. Thus it is not likely that these
hair levels represent Pb intoxication in these children.
To clarify further the possible relationship between hair trace-metal content
and metal intoxication, it will be necessary to:
1. Repeat and extend the present study by obtaining simultaneously
hair, blood, and urine samples from these children.
2. Extend and expand similar trace-metal-burden studies to include
both sexes, different age groups, and other geographic areas.
SUMMARY
Parents of fourth-grade male children living in East Helena, Helena, and
Bozeman were asked to volunteer for a study that involved saving the clippings
of their son's next haircut. Cooperation rates were 68, 54, and 84 percent,
respectively, in the three cities.
These three cities represent the following gradient for Pb, Cd, and As
pollution: East Helena > Helena > Bozeman.
Hair samples were washed and analyzed for Pb, Cd, As, Zn, and Cu. The
mean hair levels of Pb, Cd, and As differed among the three cities in the
following order: East Helena > Helena > Bozeman. Zn and Cu levels did not
differ.
REFERENCES FOR CHAPTER 8
1. Hammer, D.I. et al. Hair Trace Metal Levels and Environmental
Exposure. Amer. J. Epid. 93(2): 84-92, 1971.
2. Finklea, J.F. et al. Human Pollutant Burdens. American Chemical
Society Symposium on Air Quality, April 1,1971, Los Angeles (in
press).
3. Hammer, DJ. et al. Trace Metals in Human Hair as a Simple
Epidemiologic Monitor of Environmental Exposure. 5th Annual
Conference on Trace Substances in Environmental Health, June 29,
1971, Columbia, Mo. (to be published).
4. Engel, R.E. et al. Environmental Lead and Public Health, EPA,
APCO, Publication No. AP-90. Research Triangle Park, N.C. March
1971.
5. Forslev, A.W. "Nondestructive" Neutron Activation Analysis of
Hair. J. of Forensic Sciences 77:217-232, April 1966.
Trace-Metal Concentrations in Human Hair 133
-------
6. Jacobziner, H. Lead Poisoning in Childhood: Epidemiology,Mani-
festations and Prevention. Clin. Pediat. 5 :277-286, May 1966.
7. Kehoe, R.A. The Harben Lectures, 1960: The Metabolism of Lead
in Man in Health and Disease. J. Roy. Inst. of Pub. Health &
Hygiene, 1961.
8. Kopito, L., AM. Briley, and H. Schwachman. Chronic Plumbism in
Children. JAMA 209:243-248, July 14, 1969.
9. Kopito, L., R.K. Byers, and H. Schwachman. Lead in Hair of
Children with Chronic Lead Poisoning. New Eng. J. Med.
276:949-953, April 1967.
10. Lee, R.E., Jr., R.K. Patterson, and J. Wagman. Particle-Size
Distribution of Metal Components in Urban Air. Environ. Sci. &
Tech. 2:288-290, April 1968.
11. Neal, P.A. et al. A Study of the Effect of Lead Arsenate Exposure
on Orchardists and Consumers of Sprayed Fruit. Public Health
Bulletin No. 267, U.S. Government Printing Office. Washington,
D.C. 1941.
12. Perkons, A.K. and R.E. Jervis. Application of Radio-Activation
Analysis in Forensic Investigations. J. of Forensic Sciences
7:449-464, October 1962.
13. Perkons, A.K. and R.E. Jervis. Trace Elements in Human Head
Hair. J. of Forensic Sciences 77:50-63, January 1966.
14. Schroeder, H.A. and AP. Nason. Trace Metals in Human Hair. J.
Invest. Derm. 55:71-78, July 1969.
15. Shapiro, H.A. Arsenic Content of Human Hair and Nails, Its
Interpretation. J. of Forensic Medicine 14:65-71, April -June 1967.
134 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
POSSIBLE,HAZARDS ASSOCIATED WITH
IIMGESTION OF GARDEN VEGETABLES
CONTAMINATED BY TRACE METALS
Samuel I. Shibko,Ph.D.
DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
Food and Drug Administration
INTRODUCTION
Contamination of garden vegetables in the Helena Valley, Montana, area by
certain trace metals — arsenic, cadmium, lead, and zinc — known to be emitted
by industries in the area constitutes a potential hazard to human health. In order
to assess the adverse effects that could possibly be associated with the inclusion
in the human diet of vegetables grown in the Valley, concentrations of the
specified trace metals in the vegetables and the daily consumption of these
vegetables must first be determined. In addition, the acceptable daily intake of
arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) must be estimated. The
estimates of acceptable dietary intake given in this paper have not been derived
from definitive lexicological data but from data on the trace-metal content of
foodstuffs, air, and water, and from data on the rates and routes of excretion of
trace metals.
ZINC METABOLISM
Balance
Human zinc balance data, taken from a study by Schroeder et al.,1 are
summarized in Table 9-1. Zinc absorption and excretion are controlled homeo-
statically. In the mouse, for example, zinc homeostasis is maintained by two
Table 9-1. ESTIMATED ZINC BALANCE IN MAN1
Source
Food
Water ...
Air
Total
Zn intake,
mg/day
12.0
0.5
0.1
12.6
Excretion
route
Urine
Feces
Sweat
Other
Zn output,
mg/day
0.5
106
0.5
1.0
12 6
135
-------
mechanisms that are localized in the liver, pancreas, and gastrointestinal tract.2
Zinc absorption is influenced not only by homeostatic mechanisms but by food
constituents as well, notably phytic acid. Calcium intake, however, does not
appear to reduce zinc absorption.3
Toxicity
Zinc compounds are relatively nontoxic, although acute episodes of toxicity
have been reported. Few studies are available, however, by which to judge the
long-term effects of orally administered zinc. In one study, the administration of
ZnS04 (660 mg/day) for up to 22 months, to observe its effects on wound
healing, failed to produce any adverse effects.4 Furthermore, exposure of man
to inhalation of metallic zinc, zinc oxide, and zinc sulfide for long periods
produced no adverse effects.5 The biological half-life of zinc in man is 315 days.
CADMIUM METABOLISM
Balance
No information is available on the biological half-life of cadmium or on
mechanisms of cadmium absorption and execretion in the human, except that a
homeostatic mechanism for control of cadmium in man does not appear to exist.
Cadmium absorption from dietary intake is low. Absorption, metabolism, and
physiological effects of cadmium may be markedly influenced by other dietary
components. For example, experimental studies with laboratory animals have
shown that zinc, iron, copper, selenium, calcium, sulfhydryl compounds, and
vitamins D and C are important in this respect. Some information on the typical
daily intake of cadmium and on its excretion has been estimated by Schroeder et
al.1 and is shown in Table 9-2.
Table 9-2. ESTIMATED CADMIUM BALANCE IN MAN1
Sou rce
Food .
Water
Air .
Total
Cd intake,
Aig/day
200
15
<1
215
Excretion,
route
Urine
Feces
Air
Cd output,
jug/day
50
163
213
Toxicity
Unlike zinc, cadmium is toxic to man and other mammals, and causes a
number of adverse effects. In man, long-term industrial exposure to Cd results in
renal tubular damage, which is characterized by proteinuria. Extreme exposure
may result in osteomalacia. Studies with experimental animals indicate that
subcutaneous injection of cadmium into newborn rats causes hemorrhagic
disease of the central nervous system.6 Intermittent injections of cadmium
chloride into rabbits cause amyloid disease, but this disease has not been
136 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
associated with long-term human exposure to cadmium. The toxic effects of
cadmium in gonadal tissues have been characterized in experimental animals, but
are not known in man.
In a study on the effects of chronic exposure of rats to Cd, reported by
Schroeder et al., 7»8 rats received, from time of weaning, drinking water
containing 5 ppm Cd. Hypertension began to appear after about a year, and the
incidence, which was greatest in females, increased with age. Both sexes had
decreased median life spans compared to cadmium-free controls. In this study,
the renal concentration of Cd found in the rat kidney was less than that reported
for human kidney. Schroeder9 considers one common form of hypertension in
man to be related to the accumulation of cadmium in the kidney, probably in
the renal cortex, where cadmium is firmly chelated to a zinc- and cadmium-
containing protein.
ARSENIC METABOLISM
Balance
The estimated arsenic balance in man is given in Table 9-3, which is derived
from Schroeder and Balassa.10 The data presented in this table were calculated
for arsenate, the pentavalent form of As, which is the usual form in which
arsenic occurs in soil and water. From the data in Table 9-3, it is apparent that
no arsenate is retained in the human body. Arsenate appears to be controlled
homeostatically, and most of the arsenate that is absorbed is excreted via the
kidney.
Table 9-3. ESTIMATED ARSENIC3 BALANCE IN MAN
10
Source
Food
Water
Air
Total
As intake
ing/day
890
10
300
Excretion
route
Urine
Feces
Air
As output
M9/day
225
675
900
aBalance data calculated on assumption that all As taken is in form of
arsenate.
Toxicity
Trivalent arsenic (arsenite), as opposed to arsenate, is extremely toxic.
Arsenite chelates with the sulfhydryl groups of proteins and is only slowly
excreted, mainly via the intestine.
Hazards of Contaminated Garden Vegetables
137
-------
LEAD METABOLISM
Balance
Two slightly different estimates of lead balance in man have been suggested,
both of which are given in Table 9-4.l '>12>13
The metabolism of lead in the human, which is complex, is not fully
understood. The absorption of Pb is low and is influenced to a large degree by
the composition of the diet. For example, calcium, pectin, and protein
hydrolysates are known to interfere with Pb absorption.1!
Table 9-4. ESTIMATED LEAD BALANCE IN MAN
1 1,1 2,1 3
Sou rce
Food
Water
Air
Total
Pb intake, mg/day
Kehoe
0.22
0.10
0.08
0.40
Monier-Williams
0.31
0.02
0.02
0.35
Excretion
route
Feces
Urine
Stored in
bones
Pb output, mg/day
Kehoe
0.30
0.05
0.05
0.40
Monier-Williams
0.32
0.03
—
0.35
Following absorption, lead is distributed throughout the body, the highest
concentrations appearing in red blood cells, kidney, liver, and bone. Lead is
excreted via urine and feces.13
Toxicity
Kehoe considers the maximum allowable intake of lead to be 0.6 milligram
per day; ingestion of twice that amount is injurious after 10 years or more.14
Severe Pb poisoning causes a variety of effects, including anemia, neurological
disorders, and deranged porphyrin metabolism. As opposed to clinical stages of
lead poisoning, the symptoms of which are well known, subclinical lead
poisoning is not yet well characterized.
The effects of chronic exposure of rats to lead were studied by Schroeder et
al., who gave rats 5 ppm lead in drinking water from weaning until death. Lead
exerted a continuous adverse effect at all ages and in both sexes, as evidenced by
reduced life spans and increased mortality rates. Concentrations of lead in the
rat organs were similar to those reported for man.7
DAILY CONSUMPTION
OF GARDEN VEGETABLES AND FRUITS
In the absence of definite information on the dietary habits of residents of
the Helena Valley area, the probable daily consumption of certain garden
vegetables and fruits was estimated from data reported by Ter Haar,15 which
138 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
were acquired through a U.S. Department of Agriculture food-consumption
survey. The values given in Table 9-5 were estimated to the nearest 0.1 percent
from the USDA data, except for the values for kohlrabi and rutabaga, which
were arbitrarily determined.
Table 9-5. ESTIMATED DAILY CONSUMPTION OF GARDEN
VEGETABLES AND FRUITS15
Vegetable or fruit
Apples
Beets
Cabbage ,
Lettuce
Potatoes
String beans
Total
%of
diet
1.81
0.44
0.7
0.5
0.2
0.5
1.01
5.6
0.2
1.0
11.96
Consumption,
g/daya
27
6
10.5
7.5
3
7.5
15
84
3
15
178.5
Estimated daily consumption is based on 1500-g/day for a 60-kg (132-lb)
person.
ESTIMATED DIETARY LEVELS
OF ARSENIC, CADMIUM, LEAD, AND ZINC
The levels of dietary trace metals were estimated from the maximum values
reported by Hindawi and Neely (Chapter 5, Table 5-3). No correction was made
for contributions to trace-metal levels from dust or soil adhering to the un-
washed vegetables, although it is recognized that adhering materials could have
contributed considerably to the levels observed, particularly in the case of leafy
vegetables. As seen in Table 9-5, the vegetables for which values are given
constitute only 11.96 percent of food consumed daily. The assumption has been
made that the remaining 88.04 percent of the diet will contain As, Cd,Pb,and
Zn at concentrations approximating those reported by Schroeder for food-
stuffs.1'10'13
Although the diet represents the major source of As, Cd, Pb, and Zn, the
daily intake from air must be estimated because these elements are present not
only in soil and water but in the atmosphere as well. Contributions to metal
intake from the air were calcualted by using a factor derived from lead data
reported by Harley,16 in which the total annual intake by man of lead from the
air was calculated to be 15 milligrams if the average concentration of atmo-
spheric lead were 2 micrograms per cubic meter of air. Applying the same ratio
(of metal present in the atmosphere to that inhaled) to the upper levels of As,
Hazards of Contaminated Garden Vegetables
139
-------
Cd, Pb, and Zn that can occur in particulate matter, the daily intake of each of
the metals was obtained: As, 60 jug; Cd, 60 /ug; Pb, 80 jug; and Zn, 60 £ig.
Schroeder's estimate of the daily intake of these elements from air is: As, 2 jug;
Cd, 1 Mg; Pb, 20 to 80 jig; and Zn, 100 jug.1 'J °;1 3
The higher arsenic intake derived by means of Barley's factor, as opposed to
Schroeder's estimate, does not represent a significant difference in the total daily
intake; however, the difference in cadmium intake values represents a 25-percent
increase in total daily cadmium intake. An estimate of the total daily intake of
As from food, water, and air is given in Table 9-6.
Table 9-6. ESTIMATED TOTAL DAILY INTAKE OF ARSENIC, CADMIUM,
LEAD, AND ZINC FROM DIET, WATER, AND AIR
Metal
Arsenic
Cadmium
Lead
Zinc . . . .
Estimated intake in
uncontaminated
areas,3 jug/day
900
215
400
350
12 000
Estimated intake
in East Helena
area,b M9/day
1,016 (112%)
322.8 (150%)
855 (212%)
853 (247%)
1 3 420 ( 1 1 2%)
a Estimated values given in Tables 9-1 through 9-4.
Sum of values calculated for total dietary intake (Table 9-7), intake via inhala-
tion, and water (Tables 9-1 through 9-4). Figures in parentheses represent
estimated total daily intake in East Helena area, expressed as percentage of
estimated total daily intake in uncontaminated area.
SIGNIFICANCE OF DATA
In an attempt to estimate the possible hazards associated with the inclusion
in the human diet of garden vegetables grown in the Helena Valley area, the
contribution of these vegetables to the daily intake of As, Cd, Pb, and Zn has
been estimated and is shown in Table 9-7. In all cases, the maximum values
possible have been utilized in the calculations; that is, all vegetables in the diet
were assumed to have been grown in the area and were assumed to contain the
maximum concentrations of metals reported by Hindawi and Neely (Table 5-3).
In spite of the bias introduced by these assumptions, significant increases in
dietary intake of trace metals as the result of vegetable consumption were seen
only for cadmium and lead (based on balance levels reported in Schroeder et
al.1). Daily lead intake from vegetables in the Helena Valley area is estimated to
be double the amount reported by Schroeder et al. as balance intake (Table 94).
Daily cadmium intake is 30 percent higher than reported balance intake'fTabie
9-2).
The best indication of the significance of the high lead intake estimated to
occur in the Valley is the statement by Kehoe that the maximum allowable daily
140 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 9-7. ESTIMATED DAILY INTAKE OF ARSENIC, CADMIUM,
LEAD, AND ZINC FROM THE DIET
Metal
Arsenic
Cadmium
Lead
Zinc
Intake3 from
garden vegetables
and fruit, ,ug
164
82.8
481
2,260
Intake*3 from rest
of diet, ;ug
782
175
194
272
10,600
Total dietary
intake,0 /ug
946 (106%)
257.8(129%)
675 (304%)
753 (248%)
12,860 (108%)
Calculated on basis of data in Table 5-3 and Table 9-5.
^Based on assumption that approximately 88% of diet will contain As, Cd,
Pb, and Zn at concentrations approximating those reported in Tables 9-1
through 9-4.
cFigures in parentheses are percentages of daily intake (from diet) reported in
Tables 9-1 through 9-4.
intake of lead is 0.6 mg and that twice that amount, 1.2 mg/day, is injurious
over a period of 10 years or more.14 Although lead intake by residents of the
Helena Valley area exceeds 0.6 mg/day (from diet and air), intake is still well
below 1.2 mg/day (Table 9-6). Nonetheless, Kehoe's data were from a small
number of healthy individuals and were not necessarily representative of the
problem that exists in the Helena Valley. Thus, it would be inadvisable to
consider intake of lead at levels between 0.6 and 1.2 mg/day as being totally
without hazard. It is unlikely, however, that the actual levels of Pb in the diet
would be as high as those given in Table 9-6 and in Table 5-3,because (1) data
given in these tables were obtained on unwashed vegetables and (2) valley-grown
garden vegetables would probably not be the entire source of vegetables on a
continuous basis. On the other hand, the intake from dietary lead will greatly
exceed these figures on occasion, because dietary patterns vary. For example,
consumption of large amounts of lettuce, which appears to be a lead accumu-
lator, would greatly increase the lead intake. Such increased consumption will
probably be sporadic, however, so that the potential for danger will be mini-
mized.
In the case of cadmium, the dietary intake suggested by Schroeder et al.1 is
exceeded by approximately 30 percent, and the amount derived from air may
contribute an additional 25 percent (Tables 9-6 and 9-7). However, since
exposure via inhalation results in absorption of cadmium that exceeds absorp-
tion from the diet, the increased cadmium in air may present a greater problem
than that associated with the diet. No information is available on the significance
of this increase, although it may result in increased deposition of cadmium in the
kidneys. The various exaggerated factors that have been considered for lead also
apply to cadmium, and it is likely, therefore, that the actual intake will be
somewhat lower and that less cadmium will be ingested, absorbed, and
concentrated in the tissues. More recent publications suggest that the total
dietary intake of cadmium in uncontaminated areas is 50 Mg/day.17 The
Hazards of Contaminated Garden Vegetables
141
-------
estimates of cadmium intake in the contaminated area show a considerable
increase over this value. The general conclusions relating to the possible effects
remain unchanged.
Because limited data are available, it has not been possible to determine
whether consumption of meat or milk produced in the area will appreciably alter
the human body burden of cadmium and lead. Available data on animals in the
area indicate that the Pb and Cd in beef liver muscle, milk, chicken and rabbit
muscle, and swine heart and sausage are of the same order of magnitude as those
observed for edible meats and organs by Schroeder et al.1'13 and for milk by
Murthy and Rhea.18 The high Cd values observed for horse kidney and liver may
be the result of grazing habits of horses. Additional analyses of organs and
tissues of beef cattle raised in this area would be of value in determining whether
their inclusion in the diet is potentially hazardous.
Although no immediate, acute hazards appear to be associated with
consumption of trace-metal-contaminated vegetables grown in the Helena Valley
area, little is known about the effects of continuous exposure (from diet and
from air) to low concentrations of Cd and Pb. Because it is likely that levels of
intake will exceed those of elimination, tissue accumulation of these elements is
to be expected. Although unavailable at the present, data on trace-element
content of tissues from people who have spent most of their lives in this area
would be useful in determing effects of chronic exposure. It is not known
whether these individuals will develop a degree of tolerance to the increased
intake of these trace metals, or if accumulation of these metals will eventually
result in physiological changes.
SUMMARY
1. All calculations, estimations, and conclusions are based on assump-
tions rather than on toxicological facts. These estimates were made
because of the unusual situation that exists in the Helena Valley
area. Extensive toxicological studies will be required before defi-
nite opinions can be given regarding the effects on man of chronic
exposure to low levels of As, Cd, Pb, and Zn.
2. Calculation of the estimated daily dietary intake of these metals
from garden vegetables containing the maximum levels of the
metals indicates that the body burden of these metals suggests by
Schroeder et al.1'10'13 andKehoe14 will be exceeded for lead and
cadmium.
3. These calculations do not take into account the fact that the
vegetables were not washed before analysis, or that garden vege-
tables may only provide a fraction of the total dietary intake of
vegetables, or that the inhabitants of the area may have special
dietary habits.
142 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
4. Based on these calculations, the daily intake of lead from garden-
grown vegetables would be 0.48 mg. The daily intake of lead from
all food could be as high as 0.753 mg. The total daily intake of
lead, including that from water and air, could be as high as 0.95
mg. The second and third figures exceed the upper limit suggested
by Kehoe.14 Kehoe believes that no major hazard is associated
with this level except in the case of continuous intake for many
years; it is significant, then, that the problem in the Helena Valley
area is one of chronic ingestion of lead.
5. The significance of the increased cadmium intake — approximately
55 percent over the acceptable body burden, 30 percent of which
comes from diet and 25 percent from air — is not known. The
factors indicated in (3) above may minimize any possible hazard.
6. Inasmuch as these results apply to relatively few sections of the
Helena Valley area — namely those in which the concentrations of
trace elements are the highest reported - it would appear that, in
general, the "normal" consumption of garden vegetables in the area
is safe.
7. It should be understood that conclusion (6) does not take into
account abnormal dietary patterns and high-risk populations; it
does consider distribution of trace-metal residues to be fairly
constant year by year.
8. Additional data are required to determine whether a hazard exists
from the consumption of milk and meat derived from cattle in the
area.
9. For a more complete analysis of the problem, future studies should
include a survey of the dietary habits of the inhabitants of the area,
with particular inquiry into their preparation and consumption of
garden vegetables.
10. These conclusions apply only to this specific problem and should
not be construed as a general statement relating to the safety of
consuming foods containing these trace elements.
REFERENCES FOR CHAPTER 9
1. Schroeder, H. A. et al. Essential trace metals in man: Zinc.
Relation to environmental cadmium. J. Chron. Dis. 20:169-210,
1967.
2. Cotzias, G. C., D. C. Berg, and B. Selleck. Specificity of zinc
pathway through the body: Turnover of 6 s Zn in the mouse. Amer.
J.Physiol. 202:359-363,1962.
Hazards of Contaminated Garden Vegetables 143
-------
3. Spencer, H. et al. Studies of 65Zn Metabolism in Man. In: A.S.
Prasad (ed.), Zinc Metabolism. Springfield, 111. C.C. Thomas. 1966.
pp. 339-362.
4. Pories, W. J. et al. Acceleration of Wound Healing in Man with Zinc
Sulfate Given by Mouth. Lancet 7, 121, 1967.
5. Batcheler, R. P. et al. Clincial and Laboratory Investigation of the
Effect of Metallic Zinc, of Zinc Oxide and of Zinc Sulfide upon the
Health of Workmen. Ind. Hyg. 8 :322-363, 1926.
6. Gabbiani, G., C. Baic, and C. Deziel. Toxicity of Cadmium in the
Central Nervous System. Exp. Neurology 75:154-160, 1967.
7. Schroeder, H. A., W. H. Vinton, Jr., and J. J. Balassa. Effect of
Chromium, Cadmium and Lead on the Growth and Survival of
Rats. J. Nutrition 80:48-54, 1963.
8. Schroeder, H. A., J. J. Balassa, and W. H. Vinton, Jr. Chromium,
Cadmium and Lead in Rats: Effects on Life Span, Tumors and
Tissue Levels. J. Nutrition 86:51-66, 1965.
9. Schroeder, H. A. Cadmium, Chromium and Cardiovascular Disease.
Circulation 55:570-582, 1967.
10. Schroeder, H. A. and J. J. Balassa. Abnormal Trace Metals in Man:
Arsenic. J. Chron. Dis. 79:85-106, 1966.
11. Monier-Williams, G. W. Trace Elements in Food. New York, New
York. John Wiley & Sons, Inc. 1949. p. 68,72.
12. Kehoe, R. A. PHS Aspects of Increasing Tetraethyl Lead Content
in Motor Fuel. U.S. DHEW, Public Health Service. PHS Publication
No. 712. Washington, D.C. 1959.
13. Schroeder, H. A. and J. J. Balassa. Abnormal Trace Metals in Man:
Lead. J. Chron. Dis. 74:408425, 1961.
14. Kehoe, R. A. The Metabolism of Lead in Man in Health and
Disease. Arch. Environ. Health 2:418422, 1961.
15. Ter Haar, G. Air as a Source of Lead in Edible Plants. Environ. Sci.
& Tech. 4:226-229, 1970.
16. Harley, J. Sources of Lead in Perennial Rye Grass and Radishes.
Environ. Sci. & Tech. 4:225, 1970.
17. Frigberg, L., M. Piscator, and G. F Norberg. Cadmium in the
Environment. Cleveland, Ohio. The Chemical Rubber Company.
1971.
18. Murthy, G. K. and U. Rhea. Cadmium and Silver Content of
Market Milk. J. Dairy Sci. 57(4):610-613, 1968.
144 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
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10. POLLUTION SOURCES
Francis M. Alpiser, Marius J. Gedgaudas,
and Harold B. Coughlin
ENVIRONMENTAL PROTECTION AGENCY
Office of Air Programs
INTRODUCTION
Emission Summary for Helena Valley
An emission inventory covering sulfur oxides, particulate matter, nitrogen
oxides, hydrocarbons, and carbon monoxide was made for the Helena Valley
area in 1968. Although industrial processes are the primary source of emissions
in the Valley, fuel combustion in stationary sources, transportation, and open
burning also contribute to the overall problem.
The primary pollutant is sulfur dioxide, of which approximately 71,100
tons is emitted annually, based on operations at the time of the study. Partic-
ulate emissions, totaling nearly 8300 tons, are lower than the actual amount,
because dust from unpaved roads is a major problem in the area; no accurate
method is available for estimating such emissions, however. Carbon monoxide
emissions amounted to approximately 22,000 tons, and nitrogen oxides and
hydrocarbons totaled approximately 2600 tons and 2100 tons, respectively.
Table 10-1 summarizes the pollutants in percent for the four source cate-
gories.
Table 10-1. 1968 EMISSIONS IN HELENA VALLEY, MONTANA, AREA
Source category
Industrial processes
Fuel combustion
Transportation
Solid waste disposal
Total
Pollutants
S02
98.6
1.3
0.1
Negligible
100.0
N02
Negligible
53.0
43.9
3.1
100.0
Particulates
70.4
25.7
2.5
1.4
100.0
HC
1.2
Negligible
88.5
10.3
100.0
CO
3.4
0.2
93.5
2.9
100.0
145
-------
East Helena Industrial Complex
The complex consists of the lead smelter of American Smelting and Re-
fining Company (ASARCO), the slag-processing activities of the Anaconda
Company, and the paint pigment production of the American Chemet Corpor-
ation.
ASARCO contributes nearly 70,500 tons of sulfur oxides, or 99 percent of
the area total. This figure is based on the operations of ASARCO during the
period covered by this report. The plant, as presently operating, emits approx-
imately 120,500 tons of SO2 per year, with a potential yearly discharge of
approximately 138,000 tons if operated at full smelting capacity. Particulate
emissions are 5800 tons per year, the majority of which is emitted by the
Anaconda Company and ASARCO; other emissions are contributed by periodic
gravel crushing, asphalt batching, and stockpile blowing.
Table 10-2 lists the operations of the three contributors and the sulfur oxide
and particulate emissions for each.
LEAD SMELTING^
AMERICAN SMELTING AND REFINING COMPANY
Process Description
The American Smelting and Refining Company operates a custom lead
smelter at East Helena. The plant was built in 1885 and was acquired by
ASARCO in 1899. Figure 10-1 is a simplified flow diagram for the lead plant.
A custom smelter is a plant with flexibility to process ore concentrates from
both domestic and foreign mines. Ore concentrate is made by upgrading ore to
50 to 70 percent lead using differential flotation. The time for processing a
definite concentrate varies from 3 months to 1 year or more, depending on the
amount purchased.
Concentrates now being processed have a sulfur content greater than 30
percent. They are from the Kidd Creek Mine operated by Texas Gulf Sulfur
Company at Ontario, Canada. Domestic concentrates of lead ore used previously
had 10 to 20 percent sulfur. A return to domestic concentrates is not likely
because ASARCO is comitted to using the Canadian concentrate.
Raw Materials
Various shipments of lead concentrates are sampled to determine the metal
and sulfur contents. The concentrates, after being mixed thoroughly with zinc
residues, limestone, and siliceous ore, are then pelletized to give a charge
conforming to metallurgical requirements. The charge is delivered by belt con-
veyor to the sintering plant.
146 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
65-
2,
'£*
(-*-
o'
o
o
rtl
Table 10-2. EMISSIONS FROM EAST HELENA INDUSTRIAL COMPLEX
(tons/day)
Company
ASARCO
Subtotal
Anaconda
Subtotal
American
Chemet
Total
Operation
Sintering
Smelting
Miscellaneous
Fuming
Miscellaneous
Pigment
production
Emissions
SO2 production
Reduced
184.6
8.4
Negligible
193.0
13.0
c
13.0
Negligible
206.0
Normal
315.6
14.6
Negligible
330.2
13.0
c
13.0
Negligible
343.2
Maximum
355.1
23.2
Negligible
378.3
13.0
c
13.0
Negligible
391.3
Particulates production
Reduced
0.3
Negligible
a
0.3
b
1.0
1.0
d
1.3
Normal
0.5
Negligible
a
0.5
b
1.0
1.0
d
1.5
Maximum
0.5+
Negligible
a
0.5+
b
1.0
1.0
d
1.5+
aThe outside storage of concentrates contributes a significant but undetermined amount of particulates.
bEmissions also occur during the slag charging and at the coal mill, but no estimates have been made.
cEmissions occur when slag is dumped, but no estimate of their quantity has been made.
^Emissions are controlled by cyclones and bag filters with high collection efficiencies.
-------
00
a
«
r
r
§
z
s
w
r
3
r
s
s
z
on
TO ATMOSPHERE
ORE AND LEAD CONCENTRATION FLUXES FURNACE COKE COKE BREEZE
Figure 10-1. Simplified flow diagram for lead plant.
-------
Sintering
The charge is mixed with return sinter and fed to one of four Dwight Lloyd
sintering machines where the sulfur content is reduced through oxidation or
roasting and the charge is agglomerated into a product known as "sinter." The
sinter is screened to remove fines, and the coarse fraction is delivered to the blast
furnace. The fines are crushed and returned for blending with fresh charge from
the charge-preparation system. The gases from the sintering machies are con-
ducted through flues to an electrostatic precipitator, where most of the dust in
the gases is removed. The cleaned gases, containing about 2.0 percent S02 and
some metallic dust, are discharged to the atmosphere through a 400-foot stack.
Blast Furnace Charge
Finished sinter, together with coke, is charged to one of two blast furnaces
where it is melted and reacted to form lead bullion and slag, with oxygen-en-
riched air being used to aid the reaction. The molten products flow from the
furnace continuously through a patented tapper and are separated by gravity in a
brick-lined settler. The slag overflows the settler into slag pots for delivery to
Anaconda's zinc fuming plant. The lead bullion is tapped into pots for transfer
to the dressing plant. Off gas from the blast furnace passes through a baghouse
prior to discharge to the atmosphere through three stacks.
Lead Refining
Molten lead bullion is transported by rail to the dressing plant where it is
poured into one of several large kettles and allowed to cool. Molten bullion
contains basically lead, plus significant amounts of dissolved gold, silver, copper,
arsenic, and antimony. As the bullion cools, many of the impurities separate out
as dross, which is skimmed off and mixed with soda ash and coke breeze before
being charged to the dross reverberatory furnace. This furnace produces lead
bullion, lead-copper matte, a slag composed mainly of metal sulfides, and copper
speiss, which is metal arsenides and antimonides. The molten bullion is recycled
to the cooling kettles, while the matte and speiss are shipped to another plant
out of the area for copper recovery. The gases from the dross reverberatory
furnace are mixed with blast furnace offgases and sent to the baghouse. The gas,
which contains less than 0.2 percent S02 and traces of metallic dust, is
discharged to the atmosphere through three 117-foot stacks.
After dross removal, the bullion is further purified by the addition of sulfur
and by cooling, which result in a copper sulfide matte that is skimmed off. The
matte is shipped to another plant for recovery, and the purified bullion is cast
into large blocks for delivery to a lead refinery in another state. At this facility
the precious metals and other impurities are removed and the lead is cast into
ingots for marketing.
Emissions
The smelter emits a large amount of sulfur dioxide and a significant amount
of dust. The pollutants are emitted to the atmosphere through stacks at the
Pollution Sources 149
-------
electrostatic precipitator and the baghouse, with the emission rates varying
depending on the charge rate to the sintering plant and the blast furnaces.
Prior to the summer of 1969, both blast furnaces were operated, with a
total charge of 1200 tons per day. During the period of air quality monitoring
conducted in conjunction with this study, only one furnace was in operation at a
rated capacity of 700 tons per day. In the fall of 1969, one altered furnace with
a capacity of 1200 tons per day was placed in operation and the 700-ton-per-day
furnace was idled and placed in a'standby status. The sintering plant has a
maximum daily capacity of 1350 tons; this has been reduced, however, to
balance the feed requirements of the 1200-ton-per-day blast furnace. Unless
provisions are made for the intermediate storage of sinter, it does not appear
that the blast furnaces will again be operated simultaneously.
Sulfur Dioxide
During the period of reduced blast furnace operation, it is estimated that
193 tons of S02 per day was emitted to the atmosphere from sintering
operations and from the furnace. During normal operations, 1200 tons per day
will be charged to the sintering plant and to the enlarged blast furnace; this
charge will result in 330 tons of S02 per day being discharged to the atmo-
sphere. If both furnaces were operated simultaneously at a rated capacity of
1900 tons per day, 379 tons of S02 per day would be discharged.
The above estimates are based on information supplied by ASARCO man-
agement; those data indicate that the sintering charge contains 12 to 14 percent
lead and about 14.8 percent sulfur. About 89 percent of the sulfur in the charge
stock is emitted as SO2 during the sintering operation. Of the remaining 11
percent, a portion is emitted as S02 from the blast furnace, with only an
insignificant amount being emitted from the reverberatory furnace. The sulfur
not emitted as SO2 remains in the slag, which is sent to the Anaconda plant for
zinc recovery. The offgas from the sintering operation passes through an electro-
static precipitator for dust removal and is discharged to the atmosphere. The
offgases from the blast and reverberatory furnaces are combined and pass
through a baghouse prior to discharge to the atmosphere.
Particulates
Dust from the sintering operation passes through the electrostatic precipi-
tator prior to discharge to the atmosphere. During the time the sintering plant
was operating at a reduced rate, it is estimated that 560 pounds per day of dust
was being discharged to the atmosphere. This estimate is based on data provided
by ASARCO that the precipitator has an efficiency of 97 percent and that, when
sintering at a rate of 1000 tons per day, 800 pounds per day of dust is emitted.
At the normal sintering rate of 1200 tons per day, it is estimated that 960
pounds per day will be emitted, whereas at the maximum rate of 1350 tons per
day, 1080 pounds per day will be emitted. These losses would be considerably
larger if a more reasonable precipitator operating efficiency is assumed.
150 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Plant management has reported that the baghouse serving the blast and
reverberatory furnaces has an operating efficiency greater than 99 percent. With
no other data available it is estimated that participate emissions are negligible
from this source.
Another source of particulate emissions results from the outside storage of
concentrates. During periods of gusty winds, considerable dust with a high lead
content is transported to areas adjoining the smelter. No estimate has been made
of the quantity of these emissions due to lack of data, but it is felt that they
may be of a significant nature.
The effluent from the precipitator and baghouse contains metals including
lead, cadmium, and arsenic. These materials are considered to be in the form of
particulates, but no estimate of the quantity has been made due to a lack of
data.
Plant Effluent
Plant effluent consists of cooling water an$ wash water from the processing
of speiss from the reverberatory furnaces. This water is discharged into ponds
that then discharge into Prickly Pear Creek.
The cooling water is discharged at a rate of 1450 gallons per minute into
retention ponds for cooling. Cooling is necessary so that the water discharged
into the creek does not raise the temperature of the creek more than 24° F
Process water from the speiss operation is discharged into the ponds for a period
of 1 hour per day at a rate of 600 gallons per minute.
The cooling water is essentially free of metals, but the speiss process water
has high concentrations of them. Analysis by the State of Montana of the
retention pond's discharge into the creek indicates the following metals and their
concentrations in parts per million: arsenic, 0.8 (0.03); copper, 1.12 (0.086);
lead, 0.58 (0.044); and iron, 1.10 (0.80). Concentrations indicated within
parentheses were found in samples taken from the creek downstream of the
plant.
Air Pollution Control
Sulfur Dioxide
American Smelting and Refining Company has made no attempt to remove
or recover the S02 emitted during sintering and smelting operations. A 400-foot
stack is used to reduce the ground-level impact near the smelter of SO2
emissions from sintering.
Three monitoring stations are used to regulate the operation at the sintering
plant. Ground-level SO2 concentrations are recorded in the vicinity of the plant
complex by the monitors that are situated approximately 1 to 1.5 miles from
the stack. When any station indicates a concentration of 0.7 ppm S02 for 15
minutes or longer, the sintering plant is to be shut down and is not to be started
Pollution Sources 151
-------
up again until the station indicates an SO2 concentration of less than 0.5 ppm
for 15 minutes or longer. The time required for the reduction varies from 1 to 3
hours, but is normally less than 2 hours.
In the spring of 1970, ASARCO placed in operation an induced-draft fan
and stack heater in the 400-foot sintering plant stack. These additions increased
the effluent from 190,000 cfm at 140° to 325,000 cfm at 260° F in an effort to
allow the stack plume to penetrate the frequent, intense inversions that occur in
the East Helena area. It is estimated that this has increased the effective stack
height from 533 to 743 feet when meteorological conditions are favorable. When
an intense inversion of 20° to 40° F occurs, the effective stack height will be
significantly lower. Intense inversions with 1000- to 1200-foot ceilings occur in
the Helena Valley about two-thirds of the mornings from September through
February. When an intense inversion exists, the plume will be unable to pene-
trate the inversion and will result in high ground-level S02 concentrations caused
by the inadequate dilution.
Emission control techniques are presently available than can substantially
reduce the S02 emissions from the sintering and smelting operations. The
selection of a technique to control S02 emissions will depend upon such factors
as the required degree of control and the economic, social, and political ramifi-
cations of control. Possible techniques available for control or reduction of
emissions from the sources are changes in raw feed material, the production of
sulfur or sulfuric acid, and effluent cleaning.
Canadian ore concentrates now used at the smelter have sulfur contents
greater than 30 percent. Domestic concentrates formerly processed had sulfur
contents between 10 and 20 percent. A return to domestic concentrates with 15
percent sulfur would sharply reduce S02 emissions from the sintering and
smelting operations.
Emissions of S02 from the sintering operation could be greatly reduced if
the S02 were converted to sulfuric acid or sulfur. Acid can be produced by using
a contact sulfuric acid plant, which can be designed to operate on S02 concen-
trations as low as a fraction of a percent, but economic considerations indicate
the S02 concentration should be in the range of 4 to 6 percent. It would be
necessary to improve the efficiency of the sinter plant dust-cleaning equipment
because the acid plant would be unable to operate at the present grain loadings.
Processes to produce sulfur from sulfur dioxide are also available and have
been used in Canada and elsewhere. These processes require at least partial
reduction of S02 to sulfur; this is normally accomplished by using natural gas.
The remaining sulfur oxides and hydrogen sulfide are then catalytically con-
verted to elemental sulfur. At the present, overall economics favor the produc-
tion of acid, but the use of sulfur production processes may increase due to
sulfur's ease of handling and lower transportation costs.
Scrubbing techniques are available to clean the effluent from the sintering
and smelting operations. Limestone can be used on these streams with an
estimated S02 removal efficiency of 80 percent. This type of control technique
152 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
does not provide a useful sulfur by-product and, for this reason, may best be
applied to streams not suited for acid- or sulfur-recovery processes.
Particulates
The control of particulate emissions from plant processes is attempted by
using an electrostatic precipitator to control sintering emissions and a baghouse
to control the combined emissions from the blast and reverberatory furnaces.
Little or no control of dust emissions from the storage piles has been attempted.
Prior to discharge to the precipitator, the gases are cooled and conditioned
by water sprays in the flue system. The electrostatic precipitator was installed in
1927 and has a reported collection efficiency of 97 percent. That efficiency
would appear to be quite high, however, considering its installation date; the
actual collection efficiency is estimated to be 90 to 92 percent. When sintering
at a rate of 1000 tons per day, the lower efficiency would increase dust
emissions from 800 pounds per day to approximately 2700 pounds per day, or a
three-fold increase in emissions. The opacity of the precipitator discharge is
difficult to determine due to the entrained water vapor, but at one point in the
plant inspection the sintering operation was shut down and restarted without
water being added to the gas stream. An opacity of 30 to 35 percent was
observed for approximately 20 minutes before the addition of water vapor
resulted in an opacity of 100 percent.
Effluents from the blast and reverberatory furnaces are combined and
cooled by radiation in a long flue prior to discharge to the baghouse. The
baghouse was installed in 1918 and has a reported collection efficiency of 99
percent. No visible emissions were noted at the baghouse stacks except when the
bags were periodically rapped, which resulted in an opacity of 15 percent.
Techniques are available to reduce particulate emissions from the sintering
operation. The precipitator can be replaced with a new unit capable of 99
percent reduction, or a baghouse can be used to give maximum collection
efficiency. If a process is employed to convert the S02 in the gas stream to
sulfuric acid or sulfur, increased particulate collection efficiency will be required
to avoid fouling of converters.
Particulate emissions from the yard storage of concentrates can be reduced
by enclosing the storage area and maintaining a moisture content sufficient to
eliminate the formation of dust. The scrubbing of dilute SO2 gas streams will
also reduce particulate emissions by approximately 90 percent, which indicates
that streams treated in this manner will require further treatment for dust
removal.
SLAG PROCESSING - ANACONDA COMPANY
Process Description
The Anaconda Company operates a slag-processing plant that is charged
with slag from the nearby lead smelter of American Smelting and Refining
Pollution Sources 153
-------
Company. The charge contains 15 to 18 percent zinc and 1.5 percent lead.
Approximately 100 tons per day of product is recovered, which consists of 91
percent of the zinc and virtually all of the lead in the charge stock. The mixture
of zinc and lead is recovered in a baghouse in the oxide form after volatilization
and cooling. Figure 10-2 is a simplified flow diagram for the slag-processing
plant.
Fuming Furnace Charge
Both molten slag received directly from ASARCO and cold slag from
storage are charged to the fuming furnace along with pulverized coal, which is
used as fuel to heat the charge to approximately 2200° F. The coal and blast air
enter the water-jacketed furnace near the bottom of the slag bath. The zinc and
lead are vaporized and subsequently oxidized, and are drawn from the furnace
through a flue and cooling system by an induced-draft fan before recovery. After
the oxides have been formed and removed from the furnace, the slag is removed
for disposal in a dump.
Cooling and Recovery System
The oxides and other gases are cooled first by water sprays in balloon flues
to 1000° F and then by radiation and convection in U-shaped tubes to approx-
imately 300° F If additional cooling is required, it is done by air dilution to a
final temperature of approximatley 250° F before discharge to the baghouse.
After recovery, the fume is loaded into open gondola-type hopper cars for
shipment to a zinc refinery for further processing.
Emissions
The fuming operation emits sulfur dioxide and particulates at the charging
door of the furnace and through stacks at the baghouse. In addition, particulates
are emitted through a stack at the coal-pulverizing mill, and particulates and S02
are released when the residue slag is dumped.
Sulfur Dioxide
When charging 645 tons per day of molten slag and 55 tons per day of cold
slag along with 140 tons per day of pulverized coal, the S02 emissions from the
fuming furnace are estimated to be approximately 13 tons per day. This offgas
passes through a baghouse prior to discharge to the atmosphere. In addition, an
undetermined amount of S02 is emitted when the slag is charged to the furnace.
Additional S02 emissions occur at the slag dump when the residue slag is
dumped; no estimate of the quantity of such emissions has been made, however,
due to lack of data.
Particulates
When molten slag is charged to the fuming furnace, copious emissions of
white fumes are emitted at the charging door. These emissions occur for
154 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
"0
O
t/5
O
I
GO
COAL
COLD RECLAIMED SLAG
COAL
PULVERIZER
HOT SLAG
ZINC OXIDE
Figure 1,0-2. Simplified flow diagram for slag-processing plant.
-------
approximately 5 minutes during each addition of slag. It is estimated that the
fume consists mainly of the oxides of zinc, lead, and possibly cadmium;
although no estimate of the quantity has been made due to lack of data, it is
believed to be considerable.
The oxide fume formed by the operation is collected by a baghouse that is
estimated to have a relatively high collection efficiency. For this reason it is
estimated that the particulate emissions are negligible from this portion of the
source.
Particulates are emitted when the residue slag is dumped. The exact amount
is not known, but it is estimated that it is in excess of 0.5 percent of the slag or
over 1 ton per day.
Particulates are also emitted at the coal-pulverizing mill. The mill discharges
through a mechanical collector and then to the atmosphere via a stack. The
discharge has been noted to be of number four Ringelmann or greater, thus
indicating a possibly significant but undetermined emission rate.
Plant Effluent
Both process and cooling waters from the facility are held in ponds for
recirculation, with no discharges into Prickly Pear Creek or any other portion of
the Valley's drainage system.
Air Pollution Control
Sulfur Dioxide
No attempt has been made to control the S02 emissions from the fuming
operation or the dumping of residue slag. After passing through a bag filter for
particulate removal, the gases from the furnace are discharged to the atmosphere
through five 100-foot stacks. At a uniform emission rate, the S02 concentration
is approximately 3 percent. Because the emission rate is greater during the initial
phase of the 2-hour cycle, it is estimated that the maximum emission rate might
be twice the uniform rate.
Emission control techniques are available that can substantially reduce the
S02 emissions. The selection of a technique to control the emissions will depend
upon such factors as the required degree of control and the economic, social,
and political ramifications of control. Possible control techniques that could be
employed are sulfuric acid production and effluent cleaning.
If required, it is possible to design a sulfuric acid plant to operate on low
S02 concentrations in the feed stream, similar to those encountered in the
fuming operation, but economically it would be very unattractive.
The most economical technique for control of S02 emissions from the
fuming operation would probably be the use of a scrubber with no by-product
recovery. The most economical scrubbing medium would be a slurry of pul-
verized limestone, CaC03. Hydrated lime, Ca(OH)2, would be more efficient,
156 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
but would be more expensive. An efficiency of 80 percent can be achieved using
limestone, while an efficiency of 90 percent can be expected if hydrated lime
with the same circulation rate is employed. The scrubber would be installed
downstream from the baghouse and would scrub the gases prior to discharge
through a new stack. The major disadvantage of this system would arise from
treatment and disposal problems with the spent scrubbing solution. The cost and
feasibility of solution treatment may well offset the economic advantages over
sulfuric acid production if large-scale treatment is required.
The S02 and dust and fume emissions from the slag-dumping operation
could be eliminated by the use of a granulating-type operation. The molten
residue slag would be quenched by a water stream inside an enclosure. The
effluent gases would then be vented to the proposed limestone scrubber to
remove particulates, fumes, and S02. Even if a scrubber were not used on the
fuming furnace effluent, it is quite possible that a small scrubber could be
employed with a much smaller circulation rate, thus reducing the spent-solution
disposal problem.
Particulates
The recovery and control of particulates from the fuming operation are
accomplished by a baghouse that was installed when the plant was built in 1927;
the baghouse was enlarged to its present capacity in 1957. The baghouse now
contains 725 Dacron bags and has an unknown but apparently high collection
efficiency that results in negligible particulate emissions.
To control particulate emissions during the fuming-furnace charging cycle, a
hood and duct exhaust system should be employed. The hood would need to be
either water cooled or lined with a refractory material. The fumes could be
vented to the existing baghouse if the zincLand lead values are to be recovered.
The increased volume to the baghouse co:uld be counter-balanced by decreasing
the amount of dilution air required. Since a considerable amount of ambient air
would be drawn into the duct system at the hood, the present temeprature
might be maintained without adding dilution air. If additional cooling is still
required, this cooling capacity would have to be installed. If a scrubber is used to
control S02 from the fuming operation, these emissions could be vented to it if
the lead and zinc oxides present are1 riot' to be recovered. It is believed that a
properly designed scrubber would be capable of handling particulate as well as
S02 emissions.
As mentioned previously, particulate as well as SO2 emissions from the
dumping of residue slag can be controlled by employing a granulating operation.
The coal-pulverizing operation generates a considerable amount of particu-
late matter. This discharge previously was passed through a mechanical collector
and discharged to the atmosphere. To reduce the excessive emissions, a baghouse
was scheduled to be installed in the spring of 1970.
Pollution Sources 157
-------
PAINT PIGMENT PRODUCTION -
AMERICAN CHEMET CORPORATION
Process Description
American Chemet Corporation operates a paint pigment facility and pro-
duces leaded zinc oxide, lead-free zinc oxide, cupric oxide, and cuprous oxide.
Figure 10-3 is a simplified flow diagram of the pigment plant.
Leaded Zinc Oxide
A white pigment for outdoor paint is made from zinc oxide obtained from
the Anaconda Company. The oxide is heated with natural gas in rotary kilns to
remove traces of coal and to react any sulfur present with the lead oxide to form
lead sulfate, the entire process being for the purpose of making the pigment as
white as possible. Exhaust gases from the kilns pass through two cyclones in
series before being cooled to 180° F by the addition of dilution air. The daily
production is approximately 15 tons; all the gases pass through a baghouse prior
to discharge to the atmosphere through a 30-foot stack.
The pigment is screened to remove oversized particles, and the fines are fed
to a No. 3 TH Micropulverizer to obtain material that is 99.9 percent finer than
a No. 325 screen. The material is then packed into bags, and the dust-laden gases
pass through a fabric filter before being discharged to the atmosphere.
Lead-Free Zinc Oxide
Another pigment is made from zinc oxide obtained from the Anaconda
facility at Great Falls, Montana. The crude zinc oxide is milled to approximately
170 mesh before being packed into bags. The maximum daily production is
about 100 tons. All dust generated passes through high-efficiency cyclones and a
baghouse before being discharged to the atmosphere.
Copper Oxides
Crude cupric oxide is obtained from the Anaconda Company and the
Kennecott Copper Corporation. The cupric oxide pigment is made by milling,
and the cuprous oxide pigment is made by the reduction of cupric oxide in a
closed retort. The cuprous oxide can be used to make two different pigments. It
is milled as is, or it is blended with cupric oxide and then milled and packed into
bags to produce two different pigments. The daily production of all copper
pigments is approximately 150 tons; all dust generated during the operation
passes through high-efficiency cyclones and fabric filters before discharge to the
atmosphere.
Emissions and Air Pollution Control
The pigments operations emit sulfur dioxide and particulates in relatively
minor amounts. Particulates probably contain small amounts of zinc, lead, and
copper, whereas the amount of the S02 discharged is insignificant. No corrective
158 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
£
5*
r+-
3'
C/2
O
tf
3
LEADED ZINC OXIDE
ZINC OXIDE
CUPRIC OXIDE
BAGHOUSE
LEAD-FREE ZINC OXIDE
COPPER OXIDES
MILLING
PACKAGING
H
BAGHOUSE
TO ATMOSPHERE
TO ATMOSPHERE
PRODUCT
ZINC OXIDE
PACKAGING
TO ATMOSPHERE
TO ATMOSPHERE
PRODUCT
TO ATMOSPHERE
PRODUCT
01
Figure 10-3. Simplified flow diagram for pigment plant.
-------
action or modification of existing air pollution control equipment appears
necessary as long as the equipment is properly maintained and the present
production output is not drastically increased.
Particulates
The gases from the kilns used in the production of leaded zinc oxide pass
through two cyclones in series and then through a baghouse after the tempera-
ture has been reduced by the addition of dilution air. The gases from the
production of lead-free zinc oxide also discharge to the atmosphere after passing
through high-efficiency clyclones and a baghouse. With collection efficiencies
greater than 99 percent, the total dust loss to the atmosphere has been reported
to be approximately 30 pounds per day.
Particulates are also discharged from the production of copper oxides. Gases
from these operations pass through cyclones and two baghouses prior to dis-
charge to the atmosphere. With collection efficiencies of 99 percent being
reported, a maximum of 10 pounds per day is reportedly discharged.
160 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
11. METEOROLOGY
AND
SOURCE-RECEPTOR RELATIONSHIPS
Paul Humphrey
ENVIRONMENTAL PROTECTION AGENCY
National Environmental Research Center
AIR MOVEMENT
Wind direction and speed are important factors in the transport of air
pollutants from source to receptor. By definition, air moves from the direction
that determines the name of the wind. Therefore, a west wind blowing across a
source of pollution will transport pollutants to the east. Also, concentrations of
air pollutants downwind from a source are normally inversely related to wind
speed. In the bowl-like Helena Valley, very low wind speeds may be associated
with a stagnation condition, whereas higher speeds ventilate the Valley, clearing
out any accumulation of air pollution that might be present,
Wind Stations
Prior to 1961, the wind sensors operated by the National Weather Service
Station at the Helena Municipal Airport were located on the roof of the control
tower at a height of 44 feet above ground level. In 1961 the sensors were moved
to a 20-foot mast located near the intersections of the runways, approximately
1600 feet from the original location. The change in exposure has not introduced
any noticeable change in the data obtained. The National Air Pollution Control
Administration* (NAPCA) installed two wind systems (Climet C-26) that were
operated during the study period. One was located on a 24-foot tower that was
set on an 8-foot platform on the roof of the three-story Cogwell Building in
Helena. The sensor itself was mounted about 68 feet above ground level. The
other site was on Prickly Pear Street in the eastern part of East Helena, where
the sensor was exposed on a towertop at 48 feet above ground level in an open
field. The stations were of the continously recording type. Wind data were
obtained visually from the charts by the "equal area" method over 1-hour
periods.
*Now the Office of Air Programs of the Environmental Protection Agency.
161
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Wind Direction
The annual wind rose, Figure 11-1, shows that the most frequent wind
direction at the Helena Municipal Airport is from the west.1 The annual
occurrence of west wind is reported to be 18 percent; west-northwest and
west-southwest winds are reported to be 14 and 13 percent, respectively; the
summation within these three sectors is 45 percent of the total winds. Easterly
winds occur least frequently. In general, the wind rose for Helena is symmetrical
about the east-west axis. Calm is observed 9 percent of the year.
November 1949 - October 1954.
0-3 4-7 8-12 13-18 >18
Figure 11-1. Annual wind rose, Helena, Montana.1
162 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
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Wind Speed
Monthly mean windspeeds for the years 1937 to 1963 for Helena, Montana,
(Weather Service Airport Station) are given in Table 11-1. Compared with other
areas in the United States, the Helena Valley has a relatively high frequency of
light winds.
Table 11-1. MONTHLY MEAN WINDSPEEDS,
HELENA, MONTANA, 1937 to 1963
(mph)
Month
January
February
March
April
May
June
Speed
6.9
7.8
8.6
9.3
9.1
8.6
Month
July
August
September
October
November
December
Speed
7.9
7.7
7.7
7.4
7.2
7.0
ATMOSPHERIC STABILITY AND TEMPERATURE INVERSIONS
In simple terms, the stability of the atmosphere is its tendency to resist or
enhance vertical motion or, alternately, to suppress or augment existing turbu-
lence.2 The atmosphere is said to have "neutral" stability when the temperature
lapse rate is essentially dry adiabatic (5.4° F per 1000 feet). If the temperature
decrease with elevation is greater than that, the condition is unstable; if the
temperature decreases at a lower rate, the condition is stable. A temperature
inversion exists in a layer of air when the temperature increases with elevation.
Within an inversion layer, however, the atmosphere can be very stable; this
condition promotes poor dispersion of air pollutants.
Air that is raised or lowered changes temperature at the dry adiabatic rate
while unsaturated. Therefore, a small volume of air that is given a vertical
motion under unstable conditions will be accelerated upward or downward
because of its density with respect to its surroundings. On the other hand, a
small volume of air that is displaced vertically under stable conditions will tend
to return to its original level.
Figure 11-2 shows typical temperature soundings obtained at various times
during a 24-hour period with clear skies and light winds.3 These vertical
temperature profiles were observed at the AEC National Reactor Testing Sta-
tion, Idaho, an intermountain desert valley location. Under similar meteoro-
logical conditions, nearly identical profiles can be observed in the Helena Valley.
With the absence of clouds and with light winds, the cooling of the ground
during the night results in the creation of a strong temperature inversion. Strong
heating of the ground during the day by solar radiation results in a rapid
decrease of temperature with height.
Meteorology and Source-Recptor Relationships
163
-------
CD ,_
50 55 60
TEMPERATURE, °F
70
75
Figure 11-2. Temperature soundings on day with clear skies
and light winds.3
The formation, deepening, and destruction of the surface-based inversion
layer can be seen in Figure 11-2. The shallow temperature inversion layer
observed at 1830 MST became more intense and deepened until sunrise, about
0700 MST. By 0900 MST, 2 hours later, the inversion was destroyed from the
surface up to an elevation of about 600 feet.
Windy conditions thoroughly mix air and tend to cause a condition of
neutral stability. Clouds exert a thermostatic control, reflecting the incoming
shortwave solar radiation and absorbing and reradiating the outgoing longwave
terrestial radiation back to the ground. Night or day, strong winds and cloudy
skies work together to create and maintain neutral stability, thereby preventing
either temperature inversions or unstable temperature profiles.
A fresh layer of snow reflects over 80 percent of the heat from the sun and
readily loses heat from its surface.4 Other conditions being the same, minimum
temperatures are lowest and inversions most intense over a snow surface. Under
such conditions, the temperature difference between the surface and the top of
the inversion may be as much as 40° F.
The Helena Valley is ideal for the formation of strong and persistent tem-
perature inversions. The factors favoring the radiation of heat are the altitude,
relative dryness, long winter nights, lack of cloudiness, and frequent snow cover
during winter months. Inversions are also favored both by the sheltering effects
of surrounding mountains, which produce low wind speeds and calms, and by
the cold air that drains at night into the Valley from the mountain slopes.
164 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
There may be considerable day-to-day variation in the maximum thickness
of the nocturnal inversion. The height of the top of the inversion layer may vary
from a few hundred feet to over 5000 feet above the ground.
Due to the moderating influence of the Pacific Ocean, most of the air
masses flowing over this area are usually warmer during winter and cooler in
summer than air masses at a similar latitude in the more continental climate
farther east of the Divide. The Big Belt Mountains act as a barrier and keep
shallow, but intensely cold, winter air masses that push southward from Canada
over the Great Plains from entering the Helena Valley. Occasionally, however,
the very cold air of continental origin is sufficiently deep to either spill over the
mountain ridges or enter the Helena Valley from the north via the valley of the
Missouri River. Afterwards the cold air is walled in by the surrounding moun-
tains, and the Helena Valley can experience a period of low temperatures lasting
a week or longer. With this condition, there is a layer of warmer air above the
cold air or there is, in effect, a persistent temperature inversion aloft that can act
as a lid and trap air pollution below it.
Typical winter and summer temperature profiles5 from heights of up to
2000 meters at the AEC National Reactor Testing Station, Idaho, are shown in
Figure 11-3. The morning (0858 MST) and afternoon (1407 MST) temperature
181-
12
T
1158
6000
5000
4000
3000
2000
1000
15
25
65
75
85
35 55
TEMPERATURE, °F
Figure 11-3. Typical high-level temperature soundings. Summer
and Winter.5
Meteorology and Source-Receptor Relationships 165
-------
profiles in winter are excellent indicators of the dissipation of the nocturnal
inversion in the lower levels by surface heating with an inversion at higher levels
being maintained throughout the day. In summer there is usually sufficient
heating to completely eliminate inversion conditions, as shown by the early
morning (0530 MST) and the late morning (1158 MST) temperature profiles.
Although temperature inversions have never been routinely measured in the
Helena Valley, the seasonal and annual frequency of inversion conditions can be
interpolated from maps prepared by Hosier.6 The values obtained from these
maps and given in Table 11-2 would be expected to be conservative - somewhat
less than the true values - because the Valley effects have been somewhat
smoothed out.
Table 11-2. SEASONAL AND ANNUAL INVERSION FREQUENCY
HELENA, MONTA
(% of total hours)
AT HELENA, MONTANA3
Season
Winter
Spring
Summer
Fall
Annual
Frequency
47
32
32
45
38
Inversions and/or isothermal conditions, based below 500 feet above station
elevations.
Data in Table 11-3, collected at a 250-foot meteorological tower located at
the Idaho Reactor Testing Station, show a higher frequency of inversion condi-
tions and may be more representative of the Helena Valley.
Table 11-3 SEASONAL AND ANNUAL INVERSION FREQUENCY
AT IDAHO FALLS, IDAHO3
(% of total hours)
Season
Winter
Spring
Summer
Fall
Annual
Frequency
52
37
45
57
48
3For this table, an inversion is defined as a condition wherein the temperature
at the 250-foot level is greater than at the 50-foot level.
166 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
The greatest number of hours of inversion occurs in the cold half of the
year. Spring is relatively cloudy and windy, but summer has more hours of
inversion than might be expected because of a high frequency of clear, or nearly
clear, nights.
Stability of the atmosphere can be estimated from surface observations by
the method of Turner,7 which was employed with National Weather Service
observations at the Helena Airport for the years 1962 through 1964 to estimate
the percent occurrence of the six categories tabulated in Table 11-4.
Table 11-4. STABILITY IN HELENA VALLEY4
Stability class
Very unstable (A)
Unstable (B)
Slightly unstable (C)
Neutral (D)
Stable (E)
Verv stable (F)
Monthly occurrence, %
Jan
0
2
7
56
15
20
Apr
0
10
9
56
11
15
July
3
19
14
29
15
20
Oct
0
8
10
36
17
?9
Annual
1
10
10
44
14
21
POTENTIAL AIR POLLUTION EPISODE DAYS
A mixing layer that has its base at the earth's surface is caused by turbulent
motions created by the mechanical flow of air over and around obstacles and by
thermally produced air currents. Mixing erodes and can destroy an inversion
layer, because thorough mixing produces a condition in which temperature de-
creases with height. The depth of the mixing layer usually varies diurnally and
can range from near zero during the night to a maximum depth during the
afternoon.
At locations such as Helena, where radiosonde observations have never been
made, mixing depths have been estimated by interpolation of data from the
nearest radiosonde stations with some consideration being given to topographic
differences.
A potential air pollution episode is defined here as a situation wherein
precipitation lasts at least 2 consecutive days, mixing height (Figure 11-4) is
equal to or less than 1500 meters (4921 feet), and average wind speed through
the layer is equal to or less than 4.0 meters per second (8.9 mph). By this
definition the total number of potential episode days during 5 years for Helena
is estimated to be approximately 25, a low number in relation to many areas.
The Great Salt Lake Valley in Utah and the Central Valley in California have ten
times as many episode days as Helena. The threat of a buildup of concentrations
over a period of 2 days or more is relatively small in the Helena Valley.
Meteorology and Source-Receptor Relationships
167
-------
TEMPERATURE PROFILE
-1200 GREEWICH MERIDIAN TIME
Mmrnr-TH '
MIXING DEPTH MAXIMUM TEMPERATURE
''..^POTENTIAL TEMPERATURE
\jT*
TEMPERATURE-
Figure 11-4. Graphical determination of afternoon (maximum) mix-
ing depth. The slope of the line of potential temperature corres-
ponds to the adiabatic lapse rate, which is 5.4°F per 1000 ft of
elevation, approximately.
PRECIPITATION AMOUNTS AND WIND SPEEDS AFFECTING
THE REPRESENTATIVENESS OF THE STUDY PERIOD
February, March, April, and May of 1969 had somewhat less than normal
amounts of precipitation. The amount of water available for spring runoff and
soil moisture, however, is likely to have been greater than usual in 1969 because
of the heavy January snow cover. The total precipitation for January was 2.78
inches, whereas the normal for the month is 0.47 inch.
As shown in Table 11-5, the months of June, July, and October were wetter
than normal, whereas August and September were somewhat drier. Only Octo-
ber had more than the normal number of days with rain. Average monthly wind
speeds were exactly normal, or near normal, except for September, which had
significantly lower wind speeds.
Concentrations of air pollutants are expected to be less on rainy days, or
when wind speeds are greater than normal. For example, June 24 to 26, a
stormy period during which 2.21 inches of precipitation fell, was a period when
meteorological conditions would have caused unusually low concentrations of
air pollution at measuring stations.
Assuming that emission rates of air pollutants were constant, wind and
precipitation conditions would have caused average air quality values that were
lower than normal for the months of June, July, and October, but somewhat
higher than normal values during September. Average concentrations for the
entire study period would have been somewhat lower than the normal, primarily
because of the precipitation periods in October.
168 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
Table 11-5. NORMAL AND ACTUAL MONTHLY WINDSPEED,
PRECIPITATION AMOUNTS, AND NUMBER OF DAYS WITH
PRECIPITATION, HELENA, MONTANA
Wind speed, mph Normal
1969
Difference
Precipitation, in. Normal
1969
Difference
Days with Normal
precipitation 0.01 1969
inch or more Difference
Jun
8.6
7.9
-0.7
2.23
3.50
1.27
13
11
-2
July
7.9
7.9
0.0
1.03
1.77
0.74
7
6
-1
Aug
7.7
7.7
0.0
0.89
0.38
-0.51
8
1
-7
Sept
7.7
6.6
-1.1
0.95
0.33
-0.62
7
5
-2
Oct
7.4
7.9
0.5
0.66
1.06
0.40
6
11
5
Mean
7.9
7.6
-0.3
1.15
1.41
0.26
8.2
6.8
-1.4
DIFFUSION ESTIMATES OF
MEAN SHORT-TERM SO2 CONCENTRATIONS
The three most significant sources of sulfur dioxide were considered for
diffusion estimates of mean short-term concentrations in the Helena Valley.
These sources were the 400-foot ASARCO stack (without and with fan and
heater), the ASARCO baghouse, and the Anaconda baghouse. A fan and heater
were installed at the ASARCO stack in the spring of 1970 to increase plume
height and thereby decrease ground concentrations.
The values of the parameters used in calculating the plume heights from
these sources are shown in Table 11-6. All rates of emissions are based upon a
charging rate of 1000 tons of ore per day to the ASARCO sintering plant.
Table 11-6. THREE MOST SIGNIFICANT SULFUR DIOXIDE SOURCES
Sources
ASARCO stack (no fan
or heater)
ASARCO stack (fan
and heater)
ASARCO baghouse (3
stacks)
Anaconda baghouse (5
stacks)
Stack
height,
ft
400
400
117
Stack
diameter,
ft
16
16
(Square,
side 8 ft)
(Square,
side 12 ft)
Stack gas
velocity,
m/sec
4.8
8.2
4.7
2.1
Stack gas
temperature,
°F
140
260
150
250
S02
emissions,
tons/day
263
263
25
11.2
a Maximum value; includes all ASARCO emissions not from 400-foot stack.
Meteorology and Source-Receptor Relationships
169
-------
The S02 emission rate for the ASARCO baghouse, 25 tons per day, was
estimated from a mass-product balance. A second estimate, which assumed more
sulfur in slag, was 11.8 tons per day. In a letter dated May 8,1970, the ASAR-
CO plant manager, Mr. S. M. Lane, stated that the correct figure was 1.8 tons per
day from the ASARCO baghouse. There are also some emissions of S02 that
occur as leakage from buildings and in the handling of slag. Therefore, the
emission rate of 25 tons per day is considered to be a maximum value. It
accounts for all ASARCO emissions not from the 400-foot stack.
Both the distance from the source to the point of maximum short-term
concentration and the concentration at that point are functions of the meteoro-
logical conditions, stack design, and physical properties of the emissions. Esti-
mates of the short-term concentrations at East Helena Park emanating from the
400-foot stack (with and without fan and heater) and the two baghouses are
presented in Table 11-7. The values are estimates of the mean concentrations for
Table 11-7. SHORT-TERM CONCENTRATIONS OF SO2 AT
EAST HELENA PARK
Stability
Very unstable
Moderately unstable
Slightly unstable
Neutral
Slightly stable
Stable
Wind speed
mph
4.5
4.5
6.7
13.4
6.7
6.7
Source
a
b
c
d
a
b
c
d
a
b
c
d
a
b
c
d
a
b
c
d
a
b
c
d
S02,
ppm
2.27
1.70
0.37
0.85
1.81
0.07
1.45
0.75
0.26
<0.01
1.71
0.72
<0.01
<0.01
1.09
0.21
<0.01
<0.01
0.79
<0.01
<0.01
<0.01
0.04
<0.01
fASARCO stack (no fan or heater); 0.56 mile from East Helena Park.
bASARCO stack (fan and heater); 0.56 mile from East Helena Park.
CASARCO baghouse; 0.5 mile from East Helena Park.
dAnaconda baghouse; 0.25 mile from East Helena Park.
170 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
time periods up to about 1 hour for the given conditions. The emission rates are
based upon materials-balance analysis of the individual plants, and all S02
generated by the processes is assumed to be emitted from the stacks.
Mean, short-term concentrations at the point of maximum potential impact
from the sources are shown, along with the distance to that point, in Table 11-8.
These values can occur in any direction from the respective sources, depending
upon wind direction.
Table 11-8. ESTIMATED MAXIMUM GROUND-LEVEL
CENTERLINE CONCENTRATIONS OF SO-
AND DISTANCE FROM SOURCE
FOR SELECTED METEOROLOGICAL CONDITIONS
Stability3
A
B
C
D
E
F
Wind
speed.
mph
4.5
4.5
6.7
13.4
6.7
6.7
AS A R CO
(without fan
and heater)
ppm
4.54
3.40
1.91
0.71
0.57
0.17
miles
0.4
0.7
1.3
3.1
8.0
31.0
AS A R CO
(with fan
and heater)
ppm
1.87
1.08
0.92
0.40
0.24
0.07
miles
0.5
1.2
1.9
4.3
14.0
43.0
ASA R CO
baghouse
Ppm
2.62
2.53
2.15
1.31
1.78
1.25
miles
0.2
0.2
0.3
0.5
0.9
1.7
Anaconda
baghouse
ppm
0.90
0.87
0.88
0.62
0.80
0.56
miles
0.2
0.3
0.4
0.5
0.9
1.7
A = very unstable; B = moderately unstable; C = slightly unstable; D = neutral;
E = slightly stable; and F = stable.
Downwash, a phenomenon that sometimes causes high ground concentra-
tions close to some elevated sources, is created by turbulence induced by nearby
objects such as buildings, trees, and bluffs. This phenomenon seems likely to
occur with the baghouse sources because of the relatively low stacks on rela-
tively large buildings. Computations of the resulting concentrations of S02 for
East Helena Park are shown in Table 11-9. It is estimated that downwash from
these two sources can cause ground-level concentrations of S02 in excess of 8
ppm in East Helena.
Fumigation conditions, as previously defined, can result in relatively high
ground-level concentrations at greater distances than those shown in Table 11-8.
For example, the estimated ground-level, centerline concentration under con-
ditions of inversion breakup (fumigation) at 6 miles from the source is 1.7 ppm
of sulfur dioxide, assuming that the source is the 400-foot ASARCO stack (with
fan and heater) and the rate of emission of sulfur dioxide (2761 grams per
second) is based upon 1000 tons per day charging rate to the sintering plant. The
windspeed is assumed to be 4.5 miles per hour.
Meteorology and Source-Receptor Relationships
171
-------
Table 11-9. CONCENTRATIONS OF SO2 AT EAST HELENA PARK
DURING AERODYNAMIC DOWNWASH FROM SOURCE BUILDINGS
WITH WINDSPEED OF 8 MPH
Stability
Moderately unstable
Slightly unstable
Neutral
Slightly stable
Source
a
b
a
b
a
b
a
b
SO2, ppra
0.75
1.16
1.68
2.22
3.59
3.37
5.09
3.71
fASARCO baghouse; distance - 0.5 mile.
Anaconda baghouse; distance - 0.25 mile.
DIFFUSION ESTIMATES OF
MEAN LONG-TERM SO2 CONCENTRATIONS
The basic diffusion model used for mean long-term concentrations is the
Martin-Tikvart model.8 The ground elevations at the sources and receptors are
considered. Where the receptor is higher than the ground level of the source, the
difference in elevation is subtracted from the plume height. It is thus possible
that a substantial plume height could be reduced to zero by a difference in
ground elevation. If the ground elevation at the source is higher than that at the
receptor, the difference is added to the plume height.
The mean afternoon mixing depth used as input to the model was 1617
meters (5300 feet). For the most unstable situations, this was increased by 50
percent. When the base of a stable layer is lower than the plume rise, the plume
penetrates into the stable layer; in such situations, the model nullifies any con-
tribution from an elevated source to ground-level pollution. This is assumed to
have occured 20 and 10 percent of the time during slightly stable and very stable
conditions, respectively. The assumptions are made that the wind flow over the
area is homogeneous and identical to that observed hourly at the National
Weather Service Forecast Office, Helena Municipal Airport, and that down wash
is negligible.
All computations are based upon a charging rate of 1000 tons per day to the
sintering plant and continuous processing of the by-products.
Four different maps of ground concentrations were prepared using the
diffusion model (Figures 11-5 through 11-8). The first of these maps (Figure
11-5) shows that the estimated pattern for the study period, June through
October, compares favorably with the observed pattern. The estimated concen-
trations are slightly greater than those observed because two of the plants were
172 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
o
3
63
a
t/>
o
I
8
0.01
0.02
a
S-
)-*•
•o
on
0.06
A ANACONDA BAGHOUSE
ASARCO BAGHOUSE
ASARCO STACK
(NO FAN OR HEATER!
WIND STATIONS
Figure 11-5. Estimated mean concentrations of SC>2 (ppm) from three sources in Helena Valley,
June through October 1969.
-------
not in operation at full capacity during the month of June. The estimated
pattern does not show small areas of high concentration near the sources because
of failure to consider downwash, building leakage, and other low-level emissions.
The second map (Figure 11-6), based on annual mean climatological data,
has a pattern similar to that of the months of the study period; because of the
seasonal variations in the ability of the atmosphere to dilute pollutants, however,
the estimated maximum for June through October (greater than 0.08 ppm) is
somewhat less than the estimated annual maximum value (in excess of 0.10
ppm). One would thus expect the observed maximum during the study period
(0.04 ppm) to be lower than the annual maximum by a similar ratio, and the
expected annual maximum to be approximately 0.05 ppm. The third map
(Figure 11-7) shows that a 40 percent reduction in the average annual maximum
value for ground-level concentrations occurs as a result of the addition of a fan
and heater to the tall stack, with all sources considered. The fourth map (Figure
11 -8) shows the ground pattern from the tall stack after the addition of the fan
and heater. Because this pattern is significantly different from the pattern
estimated to be caused by the stack and two baghouses, which more or less
matches the actually observed pattern of concentrations, it is evident that
low-elevation sources also are significant contributors to the observed S02
pollution in East Helena and vicinity.
DISPERSION OF PARTICULATE MATERIAL
The quantity and chemical compositon of airborne particles emitted by the
industrial sources in East Helena are not known. The size distributions of par-
ticles, as emitted, and physical properties such as shape and density also are not
known. Therefore, quantitative estimates of the distribution of particles at
ground level cannot be made.
Particles are released from low-elevation industrial sources in the East
Helena area as well as from the tops of stacks. The effects of low-level sources
would be most severe near the source, whereas the point of maximum concen-
tration from stack emissions occurs some distance downwind.
The baghouses and the electrostatic precipitator (ESP) favor collection of
the larger particles. The particles that escape collection, either by virtue of their
physical properties or by leakage before reaching the collectors, will attain a fall
velocity directed toward the ground. This velocity will be greater than that of
S02, which is assumed to be neutrally buoyant at ambient temperature. One
would expect, therefore, the pattern of ground-level, airborne particulate con-
centrations to show areas of maximum impact closer to the sources than the
SO2 pattern.
174 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
-------
n
o
3
§
3
re
•8
(si
2,
63
a
o
I
•3'
09
0.01
Scale ol miles
ANACONDA BAGHOUSE
O ASARCO BAGHOUSE
• ASARCO STACK
(NO FAN OR HEATER)
• WIND STATIONS
Figure 11-6. Estimated mean annual concentrations of S02 (ppm) from three sources in Helena Valley.
(No fan or heater on stack.)
-------
B
w
I
p
§
r
s
0.005
0.01
A ANACONDA BAGHOUSE
A-SARCO BAGHOUSE
• ASARCO STACK
(FAN AND HEATER)
• WIND STATION
G
D
Figure 11-7. Estimated mean annual concentrations of S02 (ppm) from three sources in Helena Valley.
-------
o
3
o
i
o
it
O
i
0.002
Scale ol miles
ASARCO STACK
WIND STATIONS
Figure 11-8. Estimated mean annual concentrations of S02 (ppm) from ASARCO stack with fan and heater.
-------
SUMMARY
Because the atmosphere is the medium by which air pollutants are
transported from the emission source, for a given source strength, its action
governs the duration and frequency of receptor exposure, and the concentration
to which any receptor will be exposed. Wind, stability, temperature inversion
conditions, and types of plume behavior are described so that they can be
related to observed or estimated concentrations of air pollutants.
The threat of a buildup of concentrations over a period of 2 days or more is
relatively small in the Helena Valley. Potentially high concentrations of air
pollution, however, can occur for shorter periods. One cause is light winds and
strong temperature inversions, with associated fumigation and trapping effects.
The other is instability during the daytime, which can cause a stack plume to
loop and reach the ground close to the source.
Diffusion calculations were made for sulfur dioxide emissions to estimate
both short- and long-term concentrations. The estimates agree with the measured
sulfur dioxide levels, show the relative effect of the different emission sources,
and will assist in the evaluation of the effectiveness of suggested control
measures to reduce ground concentrations of sulfur dioxide.
The climatology of the Helena Valley was compared with observed condi-
tions during the study period, June through October 1969, so that the
representativeness of the study period could be estimated. It is concluded that
measured air pollution concentrations are somewhat below those expected
because of the above-normal amount of rain and associated windy conditions in
June, July, and October.
178 HELENA VALLEY ENVIRONMENTAL POLLUTION STUDY
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REFERENCES FOR CHAPTER 11
1. U.S. Department of Commerce, National Weather Service Forecast
Office. Summary of Hourly Observations. Climatography of the
United States No. 30-24.
2. Recommended Guide for the Prediction of the Dispersion of Air-
borne Effluents. The American Society of Mechanical Engineers,
United Engineering Center, 345 East 47 Street, New York, New
York 10017. p. 7.
3. U.S. Department of Commerce. Atomic Energy Commission.
Meteorology and Atomic Energy. AECU 3066, p. 28. 1955 (out of
print).
4. Byers, H. R. General Meteorology. McGraw-Hill Book Company,
Inc. New York, 1959. p. 23.
5. Yanskey, G. R., E. H. Markee, Jr., and A. P. Richter. Climatology
of the National Reactor Testing Station IDO 12048. Air Re-
sources Field Research Office, National Reactor Testing Station,
ESSA, Idaho Falls, Idaho, January 1966.
6. Holser, C. R. Low-Level Inversion Frequency in the Contiguous
United States. Monthly Weather Review, 89:319-339. September
1961.
7. Turner, D. Bruce. A Diffusion Model for an Urban Area. Journal of
Applied Meteorology, 5:83-91. February 1964.
8. Martin, Delance 0. and Joseph A. Tikvart. A General Atmospheric
Diffusion Model for Estimating the Effects on Air Quality of One
or More Sources. Paper presented at the 61st annual meeting of the
Air Pollution Control Association, St. Paul, Minnesota. June 1968.
Meteorology and Source-Receptor Relationships 179
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