United States
Environmental Protection
Agency
Industrial Environmental Research EPA 600 2 79210f
Laboratory December 1 979
Cincinnati OH 45268
Research and Development
Status
Assessment of
Toxic Chemicals
Cadmium
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1 Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution-sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-210f
December 1979
STATUS ASSESSMENT OF TOXIC CHEMICALS:
CADMIUM
by
D. R. Tierney
T. R. Blackwood
Monsanto Research Corporation
Dayton, Ohio 45407
and
R. D. Willson
PEDCo-Environmental, Inc.
Cincinnati, Ohio 45246
Contract No. 68-03-2550
Project Officer
David L. Becker
Industrial Pollution Control Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental
Res.earch Laboratory - Cincinnati, U.S. Environmental Protection
Agency, and approved for publication. Approval does not signify
that the contents necessarily reflect the views and policies of
the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or
recommendation for use.
11
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FOREWORD
When energy and material resources are extracted, processed,
converted, and used, the related pollutional impacts on our
environment and even on our health often require that new and
increasingly more efficient pollution control methods be used.
The Industrial Environmental Research Laboratory - Cincinnati
(lERL-Ci) assists in developing and demonstrating new and im-
proved methodologies that will meet these needs both efficiently
and economically.
This report contains a status assessment of the air emis-
sions, water pollution, health effects, and environmental signi-
ficance o^jmercujq5j,.<.This study was conducted to provide a
better understanding of the distribution and characteristics of
this pollutant. Further information on this subject may be
obtained from the Organic Chemicals and Products Branch,
Industrial Pollution Control Division.
Status assessment reports are used by lERL-Ci to communicate
the readily available information on selected substances to
government, industry, and persons having specific needs and
interests. These reports are based primarily on data from open
literature sources, including government reports. They are indi-
cative rather than exhaustive.
David G, Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
111
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ABSTRACT
Cadmium is produced mainly as a byproduct of zinc smelting opera-
tion. Electroplating processes consume approximately 50% of the
6,045 metric tons of cadmium produced annually. It was estimated
that 5,700 metric tons/yr of cadmium are released to the environ-
ment from a variety of operations including ore refining, elect-
troplating, fertilizer use, coal combustion, and sludge disposal.
About 71% of this is in the form of landfill and 25% is in the
form of air emissions. Most of this emission is not as the
result of cadmium product. Major sources of cadmium emissions
are nonferrous metal refining and coal combustion which respec-
tively contribute 952 metric tons/yr and 235 metric tons/yr of
cadmium to the atmosphere. Cadmium contamination in water is
primarily from the electroplating industry which releases 160 met-
ric tons/yr. Waste cadmium is deposited on land areas by the
landfilling of fly ash from coal combustion and the dumping of
slag resulting from steel remelting. Sewage sludge incineration
and the application of phosphate fertilizers represent substan-
tial, but less well-defined sources of cadmium pollution. Con-
trol technology for cadmium emissions is represented by wet
scrubbers, baghouses, and electrostatic precipitators. The
efficiency of control exceeds 98% at ore refining facilities.
Under the Federal Water Pollution Control Act, cadmium is a
priority pollutant; regulatory standards will be revised by the
end of 1979. A criteria document by OSHA concerning stricter
regulations on cadmium is anticipated. Air pollution assessments
are underway to determine appropriate standards for cadmium under
the Clean Air Act. Cadmium is also a suspected carcinogen.
Information should be obtained on the amount of cadmium leached
into the environment from landfills, the population exposed to
cadmium from industry and cigarettes, the efficiency of waste-
water control technologies, and environmental levels of cadmium
around major sources (i.e., coal and waste combustion and waste
disposal).
This report was submitted in partial fulfillment of Contract
68-03-2550 by Monsanto Research Corporation under the sponsorship
of the U.S. Environmental Protection Agency. This report covers
the period November 1, 1977 to December 31, 1977. The work was
completed as of January 20, 1978.
IV
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CONTENTS
Foreword iii
Abstract iv
Tables vi
Conversion Factors and Metric Prefixes vii
Acknowledgement viii
1. Introduction 1
2. Summary 2
3. Source Description 5
Physical and chemical properties 5
Production 6
Process description 7
Uses 7
4. Environmental Significance and Health Effects .... 12
Air emissions 12
Health effects 17
5. Control Technology 19
6. Regulatory Action 20
References 21
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TABLES
Number Page
1 Cadmium 4
2 Physical Properties of Cadmium 5
3 Chemical Properties of Cadmium 6
4 Zinc Smelter Locations and Byproduct Cadmium
Production 6
5 General Sources of Cadmium Production 7
6 Cadmium Consumption by Industry 10
7 Cadmium Chemicals and Their Producers 11
8 Sources of Cadmium Contamination 12
9 Emission Factors for Cadmium from Industrial
Sources 13
10 Emission Factors for Processes Involving Cadmium. 13
11 Estimated Emission Factors for Consumptive Uses
of Cadmium 14
12 Emission Factors for Cadmium from Fuel
Combustion 14
13 Emission Factors for Cadmium from Waste
Incineration 15
14 Cadmium Emissions 15
15 Cadmium Contamination in Land and Water 16
16 Toxicities of Cadmium Compounds 18
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CONVERSION FACTORS AND METRIC PREFIXES3
To convert from
Degree Celsius (°C)
Kilogram (kg)
Kilometer2 (km2)
Meter (m)
Meter (m)
Meter3 (m3)
Meter3 (m3)
Metric ton
Pascal (Pa)
Joule (J)
Joule (J)
Watt
CONVERSION FACTORS
to
Degree Fahrenheit
Pound-mass
(avoirdupois)
Mile2
Foot
Angstrom
Foot3
Gallon (U.S. liquid)
Pound-mass
Pound-force/inch2 (psi)
Calorie (kilogram calorie)
Newton-meter
Calorie/second
Multiply by
J = 1.8 t° + 32
w
2.205
3.860 x 10-1
3.2808
1010
3.531 x 101
2.642 x 102
2.205 x 103
1.450 x 10-4
2.386 x 10-1*
1.000
0.239
Prefix Symbol
Kilo
Micro
Milli
k
y
m
METRIC PREFIXES
Multiplication factor
103
ID'3
Example
1 kg = 1 x 103 gram
1 yfi = 1 x 10"6 ohm
1 mm = 1 x 10-3 meter
Standard for Metric Practice. ANSI/ASTM Designation:
E 380-76% IEEE Std 268-1976, American Society for Testing and
Materials, Philadelphia, Pennsylvania, February 1976. 37 pp.
VI1
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ACKNOWLEDGEMENT
This report was assembled for EPA by PEDCo-Environmental Special-
ists, Inc., Cincinnati, OH, and Monsanto Research Corporation,
Dayton, OH. Mr. D. L. Becker served as EPA Project Officer, and
Dr. C. E. Frank, EPA Consultant, was principal advisor and
reviewer.
vin
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SECTION 1
INTRODUCTION
Cadmium is a toxic heavy metal that has been emitted to the
environment for many years and is found in soil, water, fish,
and food. Cadmium is chemically associated with zinc, copper,
and lead-bearing ores and is recovered primarily in conjunction
with zinc smelting. Although the toxicity of cadmium at high
levels is well known, little is known about long-term exposure
at levels found in air, water and fish and other food. This,
coupled with the fact that cadmium accumulates in the body and
is excreted extremely slowly, has raised concern over the
extent of cadmium contamination in the environment.
This report presents an overview of cadmium production processes
and end uses, environmental significance, health effects, control
technology, and present regulatory action concerning cadmium.
Both the amount of cadmium released to air, water, and land by
various sources and emission factors for operations involving
cadmium processing and use are given.
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SECTION 2
SUMMARY
Cadmium is produced as a byproduct of nonferrous metal ore proc-
essing; zinc smelter operations accounting for 76% of the avail-
able metal. Cadmium production from all sources in 1974 totaled
6,045 metric tons.3
Industrial uses of cadmium include electroplating, pigment and
phosphor production alloys, brazes, electronics, nickel-cadmium
batteries, plastic stabilizers, and fungicides. Electroplating
operations consume approximately 50% of total cadmium production.
Toxic effects of cadmium in humans have been studied extensively;
however, long-term chronic effects of cadmium exposure to humans
are relatively unknown. Workers subjected to cadmium for a
period greater than 10 yr have shown a marked decrease in respi-
ratory function. The U.S. occupational standard is 0.05 mg/m3
for 8 hr of exposure to cadmium oxide dusts.
Cadmium is listed as a priority pollutant for inclusion as a
toxic substance under the Federal Water Pollution Control Act.
Best available technology and new source and pretreatment
standards for priority pollutants are to be reviewed and revised
by the end of 1979.
Table 1 describes sources of cadmium contamination, magnitude
of emissions, and possible control. An estimated 5,700 metric
tons of cadmium are released to the environment each year.
About 25% of this emission goes to the air and 71% is destined
as landfill. A very small portion goes to the water environment.
al metric ton equals 106 grams; conversion factors and metric
system prefixes are presented in the prefatory material.
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Based upon information contained in this report, the following
needs should be considered in future studies:
• The amount of cadmium leached from landfills.
• The population exposed to cadmium from industrial use.
• The extent of exposure due to cadmium in cigarettes.
• The efficiency of wastewater control technology for
cadmium and its compounds.
• Environmental levels of cadmium around combustion sources
(i.e., coal and waste incineration).
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TABLE 1. CADMIUM
Source
:admium released
to environment,
metric tons/yr
Air Land Water Affected population
Control
Regulatory action
Ore refining 952
Figments and phosphors 10
Plastic stabilizers 3
Alloys, brazers and
electronics 2
Remelt steel 100
Fertilizer use 1
Waste incineration 36
Waste landfill
Industrial waste
disposal
Industrial use of
fungicide
Coal combustion 235
Diesel and fuel
oil use 36
Motor vehicle use 11
Cement plants 32
900
87
237
2,168
11
744
Unknown.
Ore refining would
be smaller than
coal combustion or
waste disposal.
160
Emissions from smelters
controlled by baghouses
and wet scrubbers; bag-
houses, wet scrubbers,
and electrostatic pre-
cipitators are used in
coal combustion; cadmium
in' water is removed by
chemical precipitation
and ion exchange.
Cadmium has been
named a priority
pollutant by EPA
under the Federal
Water Pollution
Control Act.
Cadmium oxide occupa-
tional standard
reduced to 0.05 mg/m3
for 8 hr period.
Recommendations by
Occupational Safety
and Health Administra-
tion to further re-
strict cadmium emis-
sions is anticipated.
Air pollution assess-
ments are underway to
determine if emission
or performance stand-
ards under the Clean
Air Act should be
initiated.
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SECTION 3
SOURCE DESCRIPTION
PHYSICAL AND CHEMICAL PROPERTIES
Tables 2 and 3 list physical and chemical properties of cadmium,
respectively (1).
TABLE 2. PHYSICAL PROPERTIES OF CADMIUM
Parameter
Value
Atomic number
Atomic weight
(12C = 12.000)
Melting point, °C
Boiling point, °C
Crystal system
Lattice constant, 10~10 m
Latent heat of fusion, J/kg
Latent heat of vaporization,
J/kg
Coefficient of linear
expansion, pm/(m)(°C)
Capture cross section for
thermal neutrons
(2,220 m/s), m2/atom
Electrical conductivity/
percent of International
Annealed Copper Standard
(IACS)
48
112.40
320.9
765
hexagonal, close-packed
a = 2.9727; a = 5.606
55,308
1,200,016
29.8
2.450 ± 0.050 x 10"25
25
20°C
700°C
Specific heat, J/kg <°C)
20°C
321°C to 700°C
Density, metric
tons/m3(°C> 8.65(25) 8.01(330 liq.)
Thermal conductivity,
W/m-°K (°C) 92(20) 90(100)
Vapor pressure,
kPa(°C) 0.1(394) 1.3(484)
Viscosity,
ID"3 Pas(°C) 2.37(340) 2.16(400)
6.83 x 10~z
36.8 x 10~2
230
251
7.93(400)
44(360)
13(611)
1.84(500)
7.56(700)
50(435)
53(7ll)
1.56(600)
(1) Kirk-Othmer Encyclopedia of Chemical Technology, Second
Edition, Volume 3. John Wiley and Sons, Inc., New York,
New York, 1964. pp. 884-899.
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TABLE 3. CHEMICAL PROPERTIES OF CADMIUM (1)
Characteristic
Description
Valence
Reactivity
Corrosion resistance
Solubility
Divalent.
Reacts with steam to form
cadmium oxide and hydrogen;
reacts readily with mineral
acids, but slowly with organic
acids; precipitates from solu-
tion with metallic zinc.
Excellent. Presence of sulfur
oxides leads to cadmium sul-
fide formation.
Insoluble in alkali hydroxides.
PRODUCTION
Cadmium is produced primarily as a byproduct of nonferrous metal
ore processing. Zinc smelter operations produced 76% of the
cadmium in the United States in 1972. Table 4 (2) lists zinc
smelter locations and cadmium production for each plant (2).
TABLE 4. ZINC SMELTER LOCATIONS AND BYPRODUCT
CADMIUM PRODUCTION (1972) (2)
Plant location
Zinc
capacity,
metric tons/yr
Cadmium
production,
metric tons/yr
Corpus Christi , TX
Amarillo, TX
Sauget, IL
Blackwell, OK
Bartlesville, OK
Monaca, PA
Palmer ton, PA
Bunker Hill, ID
TOTAL
50,000
74,000
76,000
58,000
45,000
214,000
195,000
92,000
804,000
220
327
335
255
200
941
858
406
3,542
(2) Moll, K., S. Baum, E. Capener, F. Dresch, R. Wright,
G. Jones, C. Starry, and D. Starrett. Hazardous Wastes:
A Risk-Benefit Framework Applied to Cadmium and Asbestos.
EGU-3561, U.S. Environmental Protection Agency, Washington,
D.C., September 1975. 272 pp.
6
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For 1974, four general sources of cadmium production are shown
in Table 5 (2).
TABLE 5. GENERAL SOURCES OF CADMIUM PRODUCTION (1974) (2)
Cadmium produced,
Source metric tons/yr Percent
U.S. produced zinc
ore refining
Imported ore refining
U.S. produced lead and
copper ore refining
Other sources
TOTAL
1,669
2,782
186
1,408
6,045
28
46
3
23
100
PROCESS DESCRIPTION
Cadmium is a byproduct of nonferrous metal ore processing
primarily zinc ore. Cadmium is always found with zinc usually
in a ratio of 1:1000 to 1:100. The usual form found on land, is
cadmium sulfide. No specific cadmium ore is worth mining for
its cadmium content alone.
In a typical zinc smelter operation> zinc sulfide concentrates
are preroasted, calcined, and then sent to a sintering plant.
Cadmium chloride (CdCl2) and lead chloride (PbCl2) fumes from
the sintering plant are separated from waste gases by a pre-
cipitator (1). Cadmium is put into aqueous solution with
sulfuric acid. It is then precipitated as a sponge with the
addition of zinc dust. The sponge is dried in a filter press and
steam dryer. Further refining of the cadmium is accomplished by
a reduction furnace. Figure 1 provides a flow diagram of a
typical cadmium refining process (1).
Cadmium is also produced from roasted zinc ore by electrolytic
refining. A block flow diagram of this process is shown in
Figure 2 (1).
USES
Cadmium is used in many processes and products. Because it
protects iron from rusting, its main use is in electroplating.
Cadmium-plated automobile parts are even more resistant to rust
than galvanized (zinc-coated) objects. Cadmium sulfide and
cadmium telluride are used in the electronics industry to pro-
duce photocells and light emitting diodes. Cadmium sulfide and
cadmium sulfoselenide are used as coloring agents in filled
plastics and in some paints. Cadmium stearate is a stabilizer
used in plastics to add heat resistance. Cadmium metal is
-------
ZINC-SULFIDE
CONCENTRATES
f f f i
HbRKESHOHv ™
pcrz
DWIGHT-LLOYD SINTERING PLANT -^\r%>
_t
r \\ I i I i V \
^y f j
WISHED SINTER
D ZINC RETORT
PLANT
ZINC CHLORIDE SOLN
-r-r-r^ LL DUST AA
^^N
\iV
\ / \
i ' i
RETURN
SINTER CALCIN£
PRECIP-
FLUEDUST ITATOR RESIDUE
DUST
{ | STORAGE ^ f i t
CADMIUM CHLORIDE 1 WA^CCA^
AND LEAD CHLORIDE FUMES 1 1
1
SULFURICACID
MIXING TANK
SULFURICACID
FILTER PRESS
1 IT TT
* 1 1L i-L
CADMIUM SPONGE
STEAM
1 IMF . •.
HJtL '" £
|||||I||||COTTRRLPRECIPITATOR
i SOD HIM PHI OPATF
tit ff WATER
T
lllllllll~l
1 1 1 1 1 1 1 1 f
1 ^ LEAD SULFATE TO ' CADMIUM
1 ^LEAD BLAST FURNACE SULFATE
i|jl ( ZINC DUST
J, PRECIPITATION TANK
i
^™^~fc mmmm ^ ^ ^ — — ^-i
_
DRYER 1 Kti>IIJUt
MIXER
BLUE POWDER /{ ^^\
•H^zfp-1-J 3| CADMIUM REDUCTION
1 1 FURNACE
i
METALLIC
CADMIUM
TO CASTING
1
RESIDUE
Figure 1. Recovery of cadmium in the roasting of zinc ore (1)
Kirk-Othmer Encyclopedia of Chemical Technology, Copyright (c)
1964. Reprinted by permission of John Wiley & Sons, Inc.
8
-------
HIGH-CADMIUM PRECIPITATE
UNWASHED SPONGE HIGH IN ZINC
FILTRATE TO ZINC PLANT
LEACHING SYSTEM
CAST SHAPES
TO MARKET
Figure 2. Electrolytic production of cadmium (1) .
Kirk-Othmer Encyclopedia of Chemical Technology, Copyright (C)
1964. Reprinted by permission of John Wiley & Sons, Inc.
-------
alloyed with copper which is used in the production of auto-
mobile radiators.
The use of cadmium in batteries is projected to increase by at
least 15%/yr for the foreseeable future. Although the disposal
of nickle-cadmium (Ni-Cd) batteries represents a new and growing
source of cadmium release, a number of battery recycling efforts
are under way, which may tend to counteract this emission source
in the long run. ;
Although cadmium electroplating encompasses only a small part of
the entire metal finishing industry, it represents the greatest
use of cadmium. Because its qualities are superior to other
plating materials, using substitutes is not likely to become
widespread unless it is forced by environmental regulations.
The use of cadmium pigments in plastics is expected to grow
because even though similary priced substitutes are available,
they also possess significant toxicity problems. The use of
barium-cadmium stabilizers for plastic is declining because of
the availability of cheaper substitutes. Industrial uses of
cadmium are given in Table 6 (2).
TABLE 6. CADMIUM CONSUMPTION BY INDUSTRY (1974) (2)
Cadmium consumed,
Industry metric tons/yr Percent
Electroplating
Pigments and phosphors
Plastic stabilizers
Alloys, brazes, and
Ni-Cd batteries
Fungicides
Other
TOTAL
electronics
2,949
1,270
907
227
181
11
500
6,045
49
21
15
3.8
3
0.2
8
100
Table 7 gives a partial listing of cadmium compounds and their
producers (2).
10
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TABLE 7. CADMIUM CHEMICALS AND THEIR PRODUCERS (2)
Barium cadmium tetraohloride tetrahydrate
Barium dicadmium hexachloride pentahydrate
Cadmium acetate
Cadmium acetylacetonate
Cadmium anthranilate
Cadmium bimalate
Cadmium bisulfite
•Cadmium bromide
Cadmium carbonate
Cadmium chloride
Cadmium chromate
Cadmium dichromate
Cadmium distearate
Cadmium 2-ethylhexanoate
Cadmium ferrocyanide
Cadmium fluoborate
Cadmium
Cadmium
Cadmium
Cadmium
Cadmium
Cadmium
Cadmium
Cadmium
Cadmium
fluoride
formate
hydroxide
iodide
lactate
molybdate
naphthenate
neodecanoate
nitrate
Cadmium nitrite
Cadmium orange
Cadmium oxide
Cadmium propionate
Cadmium potassium chloride
Cadmium potassium cyanide
Cadmium reds
Cadmium salicylate
Cadmium silicofluoride
Cadmium stearate
Cadmium succinate
Cadmium sulfate
Cadmium sulfide
Cadmium tartrate
Cadmium telluride
Cadmium thiocyanate
Cadmium yellows
Ethylenediaminetetraacetic acid,
disodium cadmium salt
City Chemical Corp.
City chemical Corp.
Richardson-Merrell, Inc./J. T. Baker Chemicals
MacKenzie Chemical Works, Inc.
The Shepherd Chemical Co.
Mallinckrodt, Inc./Drug and Cosmetic Chemicals
City Chemical Corp.
City Chemical Corp.
Richardson-Merrell, Inc./J. T. Baker Chemicals
Mallinckrodt, Inc./Industrial Chemicals
McGean Chemical to., Inc.
The Shepherd Chemical Co.
W. A. Cleary Corp.
Kewanee Industries, Inc./Harshaw Chemical Co.
Mallinckrodt, Inc./Industrial Chemicals
Richardson-Merrell, Inc./J. T. Baker Chemicals
City Chemical Corp.
City Chemical Corp.
CPC International, Inc./s. B. Penick Unit
The Shepherd Chemical Co.
City Chemical Corp.
Allied Chemical Corp./Specialty Chemicals
C. P. Chemicals, Inc.
Harstan Chemical Corp.
Kewanee Industries, Inc./Harshaw Chemicals
City Chemical Corp.
City Chemical Corp.
The Shepherd Chemical Co.
Richardson-Merrell, Inc./J. T. Baker Chemicals
City Chemical Corp.
City Chemical Corp.
The Shepherd Chemical Co.
The Shepherd Chemical Co.
Allied Chemical Corp./Specialty Chemicals
Allied Chemical Corp./Specialty Chemicals
Catalysts and Chemicals, Inc.
W. A. Cleary Corp.
Kewanee Industries, Inc./Harshaw Chemicals
McGean Chemical Co., Inc.
Richardson-Merrell, Inc./J. T. Baker Chericals
The Shepherd Chemical Co.
City Chemical Corp.
Hercules, Inc./Coatings & Specialty Products
H. Kohnstamm & Co., Inc./General Color Co.
ASARCO, Inc.
Richardson-Merrell, Inc./J. T. Baker Chemicals
The Shepherd Chemical Co.
City Chemical Corp.
City Chemical Corp.
Hercules, Inc./Coatings & specialty Products
H. Kohnstamm & Co., Inc./General Color Co.
SCM Corp./Chemical And Metallurgical Division
Smith Chemical and Color Co., Inc.
City Chemical Corp.
City Chemical Corp.
Dart Industries, Inc./Synthetic Products
Diamond Shamrock Corp./Process Chemicals Div.
The Norac. Co., Inc./Mathe Division
Witco Chemical Corp./Organics Division
Mallinckrodt, Inc./Industrial Cheiricals
Kewanee Industries Inc./Harshaw Chemicals
Richardson-Merrell, Inc./J. T. Baker Chemicals
ASARCO, Inc.
Eagle-Picher Industries, Inc./Electronics
Gen. Telephone & Electronics Corp./GTE
Sylvania
City Chemical Corp.
City Chemical Corp.
Eagle-Picher Industries Inc./Electronics
Division
Thiokol Corp./Ventron, Subsidiary/Alfa Products
City Chemical Corp.
Hercules, Inc./Coatings & Specialty Products
H. Kohnstamm & Co., Inc./General Color Division
SCM Corp./Chemical and Metallurgical Division
Smith Chemical and Color Co., Inc.
City Chemical Corp.
Jersey City, NJ
Jersey City, NJ
Phillipsburg, NJ
Central Islip, NY
Cincinnati, OH
St. Louis, MO
Jersey City, NJ
Jersey City, NJ
Phillipsburg, NJ
St. Louis, MO
Cleveland, OH
Cincinnati, OH
Somerset, NJ
Cleveland, OH
St. Louis, MO
Phillipsburg, NJ
Jersey City, NJ
Jersey City, NJ
Newark, NJ
Cincinnati, OH
Jersey City, NJ
Marcus Hook, PA
Sewaren, NJ
Brooklyn, NY
Cleveland, OH
Jersey City, NJ
Jersey City, NJ
Cincinnati, OH
Phillipsburg, NJ
Jersey City, NJ
Jersey City, NJ
Cincinnati, OH
Cincinnati, OH
Buffalo, NY
Marcus Hook, PA
Louisville, KY
Somerset, NJ
Cleveland, OH
Cleveland, OH
Phillipsburg, NJ
Cincinnati, OH
Jersey City, NJ
Glenn Palls, NY
Newark, NJ
Denver, CO
Phillipsburg, NJ
Cincinnati, OH
Jersey City, NJ
Jersey City, NJ
Glenn Palls, NY
Newark, NJ
Baltimore, MD
Jamica, NJ
Jersey City, NJ
Jersey City, NJ
Cleveland, OH
Cedartown, GA
Lodi, NJ
Perth Amboy, NJ
Cleveland, OH
Celveland, OH
Phillipsburg, NJ
Denver, CO
Miami, OK
Towanda, PA
Jersey City, NJ
Jersey City, NJ
Miami, OK
Quapaw, OK
Danvers, MA
Jersey City, NJ
Glenn Falls, NY
Newark, NJ
Baltimore, MD
Jamica, NY
Jersey City, NJ
11
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SECTION 4
ENVIRONMENTAL SIGNIFICANCE AND HEALTH EFFECTS
Cadmium is widespread in the environment. Emissions from produc-
tion and use of the metal are a small part of the total cadmium
emissions. This is because the cadmium in many ores is not re-
covered as a product. One estimate for emissions from cadmium
production and consumption was made by EPA in 1974, as shown in
Table 8. About 1,800 metric tons of the 6,045 metric tons con-
sumed were immediate sources of environmental contamination. The
remaining cadmium may or may not become an environmental contami-
nant. This will depend on the effectiveness of waste disposal
practices, the extent of secondary cadmium recovery and the estab-
lishment of future environmental regulations concerning cadmium.
TABLE 8. SOURCES OF CADMIUM CONTAMINATION (2)
(metric tons/yr)
~ Source Air Water Solid Total
Extraction, refining,
and production 102 7 250 359
Industrial conversion
(plating, pigments,
batteries, etc.) 15 8 102 125
Consumption and disposal
(excluding scrap proc-
essing and tire wear) 34 0 460 494
Inadvertant sources
(phophate fertilizers,
sludge disposal, etc.) 151 10 720 881
TOTAL 302 25 1,532 1,859
AIR EMISSIONS
The emissions of cadmium from various industrial and commerical
operations have been studied extensively. Table 9 shows esti-
mates of cadmium release from various metallurgical refining
processes. Table 10 gives emission factors for industrial
processes involving cadmium, and Table 11 contains estimated
12
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TABLE 9. EMISSION FACTORS FOR CADMIUM FROM INDUSTRIAL SOURCES
Source Emission factor, g/kg
Mining of zinc-bearing ore 0.00053
8
Zinc smelters 1.0
Copper smelters 0.4^
c
Lead smelters 0.1
Cadmium refining units 13
e
Secondary copper 2
Secondary lead 0.0002
Steel scrap (galvanized metal) 0.001^
Cement plants: ,
Dry process 0.0002fj
Wet process 0.0001
g/kg of zinc. eg/kg of copper scrap.
g/kg of copper produced. g/kg of lead produced.
g/kg of lead produced. g/kg of steel produced.
g/kg of cadmium produced. g/kg of feed.
TABLE 10. EMISSION FACTORS FOR PROCESSES INVOLVING CADMIUM
Emission factor,
g/kg of
Source cadmium charged
Pigments 8
Plastic stabilizers 3
Alloys and solders 5
Batteries (Ni-Cd) 1
Miscellaneous (x-ray screens
cathode ray tubes, nuclear
reactor components, etc.) 1
emission factors for consumption of cadmium-containing end
products. Table 12 and 13 give emission factors from fuel
combustion and waste incineration, respectively.
13
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TABLE 11. ESTIMATED EMISSION FACTORS FOR
CONSUMPTIVE USES OF CADMIUM
Source Emission factors
Rubber tire wear, g/km driven 0.003
Fungicides, g/m3 applied fungicide 20
Superphosphate fertilizers,
g/kg applied fertilizer 0.0001
Motor oil consumption,
g/103 km driven 0.0006
Cigarettes, yg/20 cigarettes smoked 16
TABLE 12. EMISSION FACTORS FOR CADMIUM FROM FUEL COMBUSTIONS
CadmiumEmission
Source content, ppm factor
Heating oil (residual assumed) 0.4 to 0.5 4 to 0.05
Diesel oil 0.07 to 0.1 0.09 to 0.073
Foreign No. 6 residual fuel oil:
Virgin Islands 5 5
Virgin Islands
(different oil fields) <0.4
Curacao, NA 44
Trinidad 3 3
Venezula <0.4
Coal, power plant:
Kansas 0.1
Coal, power plant:
Michigan 0.5
g/m3 of oil consumed.
g/metric ton of coal burned.
NOTE: Blanks indicate cadmium content is below detection
limits.
14
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TABLE 13. EMISSION FACTORS FOR CADMIUM FROM WASTE INCINERATION
Emission factor,
Source g/kg of waste
Sewage sludge incinerators:
Multiple hearth 0.004
Fluidized bed 0.0002
Municipal incinerator:
Refuse only 0.0004
Refuse and sludge 0.0003
Overall value for un-
controlled solid waste
incineration (municipal) 0.0002
Lubricating oil 0.2a
ag/m3 of oil.
In Table 14, the mass of cadmium air emissions from all types of
sources are summarized (2). Compared to Table 10, over nine
times as much cadmium is estimated to be emitted from all ore
refining than from cadmium-producing ore refining alone.
TABLE 14. CADMIUM EMISSIONS (2)
Mass of emissions,
Source metric tons/yr
Ore refining (zinc, copper, and
lead) 952
Pigments and phosphors 10
Plastic stabilizers 3
Alloys, brazes, and electronics 2
Remelt steel 100
Waste incineration 36
Fertilizer use 1
Coal combustion 235
Diesel and fuel, oil use 36
Motor vehicle use 11
Cement plants 32
TOTAL 1,418
Land and Water Contamination
Water pollution due to smelter operations has been studied ex-
tensively by EPA; cadmium discharge was found to vary from
15
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0.05 g/m3 to 33 g/m3. Application of effluent limitation guide-
lines published in 1975 is expected to reduce cadmium pollution
of wastewater from all smelter operations to acceptable levels.
Perhaps the most significant source of water-borne cadmium
pollution is the estimated 20,000 electroplating shops through-
out the country which contribute to the 160 metric tons/yr of
cadmium released into the water. Table 15 gives the amounts
of water and land contamination due to cadmium (2).
TABLE 15. CADMIUM CONTAMINATION IN LAND AND WATER (2)
(metric tons/yr)
Source Land Water
Industrial use of fungicide 11
Industrial waste disposal - 160
Waste incineration 237
Waste landfill 2,168
Kernelt steel 900
Fertilizer use 87
Coal combustion:
Bottom ash and slag 245
Electrostatic precipitators 499
TOTAL 4,147 160
Not applicable.
Population Exposed
Cadmium can impact people in a number of ways. Both airborne and
waterborne cadmium contribute to an increased concentration of
cadmium in soil. In nonindustrialized areas, cadmium in soil is
generally less than 1 ppm. The concentration around some
localized cadmium point sources reaches 50 ppm or higher. Plants
and fish act as bioconcentration media, providing foodstuffs with
sometimes alarmingly high cadmium levels. The theoretical models
of uptake and excretion of cadmium by humans suggest that the
biological half-life is between 15 yr and 25 yr.
Persons may be exposed to high cadmium concentrations in urban
areas where industrial consumers of cadmium are usually located
such as plating operations, battery manufacture, and pigments
production. Cadmium in effluents from these plants, when bio-
accumulated in plants and fish, pose a health hazard through a
contaminated food chain. Waste incineration and coal combustion
are operations which expose a large population to low levels of
cadmium compounds. The extent and level of this exposure is
unknown. Populations affected around ore refining operations are
generally small since the ore is usually processed near the mine
16
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in rural areas. A large portion of the U.S. population may be
exposed to cadmium in tobacco which is released as cadmium oxide
upon combustion in cigarettes (3).
HEALTH EFFECTS
Cadmium taken orally by humans in the range of 14.5 mg to 326 mg
causes nausea and vomiting but not mortality (4). The ingestion
of cadmium salts induces salivation, choking, diarrhea, vertigo,
and unconsciousness (4).
Studies have shown that workers exposed to low levels of cadmium
exhibited deterioriated respiratory, functions after only several
years of exposure (4).
The normal exposure to cadmium in the environment is not to the
metal but rather to cadmium compounds. Selected toxicities for
suspected carcinogens containing cadmium compounds are given in
Table 16 (5). The 8-hr time-weighted average Threshold Limit
Value (TLV®) for cadmium oxide in air is 0.05 mg/m3, while the
metal dust has a TLV of 0.2 mg/m3 (6).
(3) Anderson, D. Emission Factors for Trace Substances.
EPA-450/2-73-001, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina, December 1973. 80 p.
(4) Fasset, D. W. The Metals (Excluding Lead). In: Industrial
Hygiene and Toxicology, Chapter XXVI, F. A. Patty, ed.
Interscience Publishers, New York, New York, 1962.
pp. 1013-1016.
(5) Suspected Carcinogens. A Subfile of the NIOSH Toxic Sub-
stance List. H. E. Christensen and T. T. Luginbyhl, eds.
NIOSH 75-188, U.S. Department of Health, Education, and
Welfare, Rockville, Maryland, June 1975. 342 pp.
(6) TLV's, Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment with Intended
Changes for 1975. American Conference of Governmental
Industrial Hygienists, Cincinnati, Ohio, 1975. 97 pp.
17
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TABLE 16. TOXICITIES OF CADMIUM COMPOUNDS (5)
Compound
Cadmium oxide
Cadmium chloride
Lethal inhalation
concentration ,
mg/m3
500
700
4,000a
2,500a
320
8C
Animal
Rat
Mouse
Dog
Rabbit
Dog
Dog
Percent kill
50
50
50
50
90
10-min exposure.
'Lowest single dose observed not to cause death.
%
'30-min continuous exposure.
18
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SECTION 5
CONTROL TECHNOLOGY
Control technology exists for reducing air and water pollution
by cadmium from industrial processes. Other processes which
permit large amounts of cadmium to enter the environment are not
as easily controlled; e.g., cadmium in sewage sludge and cadmium
as a contaminant in superphosphate fertilizers.
The most common methods of removing cadmium from smelter flue
gases are baghouses and wet scrubbers. Efficiencies of 99% to
99.8% have been reported. Since cadmium collected can be
separated from other constituents and sold, there is no techno-
logical barrier in controlling smelter operations; however, dis-
posal still may be a problem. In recycling cadmium-bearing
scrap, the iron and steel industry uses baghouses, wet and dry
electrostatic precipators, and wet scrubbers to control fine
particulate emissions. Efficiencies of 98% to 99.9% are reported
for various processes. The resulting flue dust is usually
disposed in landfill operations, where the cadmium may leach-into
the water table.
Dissolved cadmium in water may be removed by chemical precipi-
tation, ion exchange, solvent extraction, or electrolytic
deposition (7). Cadmium in the form of suspended particulate
may be removed by settling ponds or thickeners (7). The effi-
ciencies of these control technologies for cadmium are unknown.
(7) Scientific and Technical Assessment Report on Cadmium.
EPA-600/6-75-003, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina, July 1975. 69 pp
19
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SECTION 6
REGULATORY ACTION
Under the Federal Water Pollution Control Act, as amended, the
EPA has classified cadmium as a priority pollutant for study.
Promulgation of new effluent standards for various industries may
result. Best available technology and new source and pretreat-
ment standards are to be reviewed and revised by the end of 1979.
Water quality criteria will also be developed by mid-1978 for
priority pollutants. The U.S. occupational standard for 8 hr
of exposure has been reduced to 0.05 mg/m3 for cadmium oxide
dusts (6). A criteria document recommending tightening the
Occupational Safety and Health Administration (OSHA) controls
is anticipated (8). An air pollution assessment on cadmium
has been underway to determine if emission or performance
standards under the Clean Air Act should be developed: Richard
Johnson, EPA/OAQPS, 919-688-8146, X-501 (8).
(8) Identification of Selected Federal Activities Directed to
Chemicals of Near-Term Concern. EPA-560/4-76-007, U.S.
Environmental Protection Agency, Washington, D.C.,
September 1976. 21 pp.
20
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REFERENCES
1. Kirk-Othmer Encyclopedia of Chemical Technology, Second
Edition, Volume 3. John Wiley and Sons, Inc., New York,
New York, 1964. pp. 884-899.
2. Moll, K., S. Baum, E. Capener, F. Dresch, R. Wright,
G. Jones, C. Starry, and D. Starrett. Hazardous Wastes:
A Risk-Benefit Framework Applied to Cadmium and Asbestos.
EGU-3561, U.S. Environmental Protection Agency, Washington,
D.C., September 1975. 272 pp.
3. Anderson, D. Emission Factors for Trace Substances.
EPA-450/2-73-001, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina, December 1973. 80 p.
4. Fasset, D. W. The Metals (Excluding Lead). In: Industrial
Hygiene and Toxicology, Chapter XXVI, F. A. Patty, ed.
Interscience Publishers, New York, New York, 1962.
pp. 1013-1016.
5. Suspected Carcinogens. A Subfile of the NIOSH Toxic Sub-
stance List. H. E. Christensen and T. T. Luginbyhl, eds.
NIOSH 75-188, U.S. Department of Health, Education, and
Welfare, Rockville, Maryland, June 1975. 342 pp.
6. TLV's, Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment with Intended
Changes for 1975. American Conference of Governmental
Industrial Hygienists, Cincinnati, Ohio, 1975. 97 pp.
7. Scientific and Technical Assessment Report on Cadmium.
EPA-600/6-75-003, U.S. Environmental Protection Agency,
Research Triangle Park, North Carolina, July 1975. 69 pp.
8. Identification of Selected Federal Activities Directed to
Chemicals of Near-Term Concern. EPA-560/4-76-007, U.S.
Environmental Protection Agency, Washington, D.C.,
September 1976. 21 pp.
21
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-79-210f
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Status Assessment of Toxic Chemicals:
Cadmium
5. REPORT DATE
December 1979 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
T.R. Blackvood, D.R. Tierney
R.D. Willson
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corp. PEDCo Environmental, Inc.
1515 Nichols Road lll+99 Chester Road
Dayton, Ohio U5li07 Cincinnati, Ohio U52U6
10. PROGRAM ELEMENT NO.
1AB60U
11. CONTRACT/GRANT NO.
68-03-2550
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Lab.
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 1*5268
- Cinn, OH
13. TYPE OF REPORT AND PERIOD COVERED
Tn.Rk Final 11 /77-1 P/77
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
lERL-Ci project leader for this report is Dr. Charles Frank, 513-68U-HU81
16. ABSTRACT
The processing, uses, and properties of cadmium are discussed in the report. The
effects, major sources, and amounts of cadmium pollutant are listed, along with
.the control technology currently available. Regulatory actions to deal with the
cadmium pollution problem are explained, and areas requiring further study are
identified.
7.
KEY WORDS AND DOCUMENT-ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Cadmium, metals, transition metals,
cadmium isotopes
Zinc, smelting, electro-
plating, nonferrous meta .
refining, coal combustio:i
68A
68D
68G
8. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
30
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
' 22
A U.S. GOVERNMENT PRINTING OFFICE 1980-657-146/5511
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