A Survey. Sources of Mercury Pollution
and Potential Human Exposure, U.S.
Prepared for the ^Mercury Task Force
by
Office of Toxic Substances
Tom Loder
Bill Coniglio
' David Garre11
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Mercury Pollution in the U.S. by Source Category
I. Mining
a) Assume an emission factor of 1 1 tons of dust
lost per 1,000 tons of mined ore processed
Tons
b) Industry Tonage (Est ) Cone, of Hg Dust Lost
Mercury 268,000 51bs/Ton 294
Zinc 18,000,000 1 20,000
Lead
Copper 223,752,000 .5 245,000
c) Assume the above industries emit 50% of the
mercury from dusting in ore processing operations
d) 1.255x2=2.5 tons Hg emitted per year
e) Assume 1971 data is applicable to 1974.
II. Smelting1
1) Primary Mercury Processing
a) Total production in 1971 was 1,339,794 Ibs.
b) Assuming an average of 5 Ibs/Ton then the tonnage
of ore mined was
(1,339,794 lbs)/(51b/Ton) = 267,959 Tons
c) Designers indicate that approximately 1600
SCFM of stack gases are emitted for each 100 T/D of
ore furnaced.
d) Using the above information, 25 Ibs. of Hg are
emitted for each 100 tons of ore processed.
e) [267,959 Tons/(100 Tons)] x (251bs/100 Tons) =
67,000 Ibs or 33.5 tons
f) Assume 1971 data is applicable for 1974
2) Secondary Mercury Production-^-
a) Secondary mercury production in 1971 was 16,670 flasks
b) EPA data indicate a retort operates at a flow rate
of 20 CFM and effluent gases have a concentration of
5000 ug/m3
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c) A typical mercury sludge charge is 300 Ibs and
has a 50% Hg contenr
d) Emissions per charge (20)(1440)(.005)A35 31 =
M- 8g for each 150 Ibs (2 flasks) of Hg produced
e) Probably most of the mercury emissions from this
operation occur with manual charging and discharging
of the ore, therefore for estimation purposes 10 times
the effluent emission will be assumed to come from
opening and closing of the retort. Total emissions
per flask »
(4 8g + 48g)/2 = 26.4g/flask
f) 1971 emissions were
(16,670)(26.4g/fl.)/(454g/lb.)(20001b/Ton) = 5 tons
g) Assume 1971 data is applicable to 1974
3) Non-Ferrous Ore Processing1
a) Mercury is found in all primary non-ferrous ores
in trace amounts varying from 05 to 600 ppm. During
the extraction of the non-ferrous metals from their
associated ore concentrates, mercury is volatilized
and becomes part of either waste or process gas streams.
Representative samples of the non-ferrous industries'
zinc, lead, and copper concentrates have been collected
and their Hg content determined by neutron activation
analysis.
b) Direct atmospheric emissions of mercury from non-
ferrous ore processing has initially been calculated
to be
Avg Emission
Industry Concentrate Processed Emissions Factor
(1 x 1Q6 Ton/Yr) (Tons/Yr) (Ib/Ton Cone)
Primary Lead 1 11 .01
Primary Zinc 1.8 5 .012
Primary Copper 6.5 35 .011
The following assumptions were used in estimation of
these figures
(1) The samples of non-ferrous concentrate which
were collected and analyzed are representative of
the non-ferrous process input.
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(2) All of the mercury which is contained in the
process input is volatilized during the first major
pyrometallurgical step.
(3) All primary non-ferrous operations which do
not pass their first-sxep pyrometallurgical gas
stream through an acid plant will emit 100 percent
of their mercury input to the atmosphere
(4) All primary non-ferrous operations which do
pass their first-step pyrometallurgical gas stream
through an acid plant will emit 10 percent of the
mercury input to the atmosphere. The remaining
90 percent of the mercury input will be absorbed
by the produced acid and collected by various acid
plant equipment
(5) Assume 1971 data is applicable to 1974
III. Fossil Fuel Combustion
Coal
a) The best current estimate of the mercury content
in coal (U.S.) is .18 ppm-^-. Based on a consumption of
522,000,000 tons2 and the assumption that 90% of the
mercury is volatilized, the total atmospheric emissions
are
(522)(.18)(.9) = 85 tons -.-- . . . -- -
b) Assuming that the 10% not emitted remains in the
ashe and is disposed of in a landfill, the total mercury
entering land via coal combustion is.
(522)(.18)(.l) = 9 tons
Oil
a) Using a Hg content of .06 ppm^ as an average,
an annual oil consumption figure of 1,560,638 million
pounds and the assumption that 90% of the mercury is
volatilized the total atmospheric emissions from oil
combustion is
(780M.06) - 47 tons (.9) = 42 tons
b) Assuming that the 10% not emitted remains in the
ash and is disposed of in a landfill, the toral mercury
entering the land environment via oil combustion is.
(.1)(47) = 5 tons
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Natural Gas
a) Using a 1967 figure for World Consumption of
natural gas of 6 x 10^ Tons/Yr and an average mercury
content of . 04 ppm, the worldwide releases of mercury
from natural gas are 20 tons yr 3
b) Assume that the U.S. consumes 50% of the world
total for 1967 and 90% volatilization of mercury in
the gas.
(.9)(.5)(20) = 9 tons
c) Assume that 10% of the mercury remains in the
ash and is deposited in a landfill. Total contribution
from natural gas combustion to mercury introduced into
land
(.!)(. 5)(20) = 1 ton
IV. Chlor-alkali Industry
a) According to a 1973 Battelle Report, the annual
discharge of mercury to waters was 10 tons.1*
b) Of the 30 chlor-alkali plants in the U.S., 24
were reported to Battelle. The average discharge for
the 24- plants was 654 6 Ibs/year. For estimation pur-
poses this average annual discharge rate was also
assigned to the 4 plants that no data was available for.
c) It is assumed that the reported discharges are
typical of the daily discharge rates for these plants.
d) An average of 10 Ibs of mercury is emitted to the
atmosphere for every 100 tons of chlorine produced. 3
e) Assuming that all plants are operating at the
production rates as reported to Battelle4 then the total
tonnage of chlorine produced annually is 4,065,370 tons/
yr.
f) Total atmospheric emissions are:
(10 Ibs Hg)(4065 4 tons C12) = U0,654 Ibs Kg or
20 3 tons
Batteries
a) An estimated 400 tons of mercury will be used by
the batteries industry with a 9% recycling of mercury
annually. 5
(.09X400) = 36 tons
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b) It is assumed that the remaining 364 tons of
mercury eventually gets into the environment.
c) Twenty-seven percent of all mercury contained
in batteries is eventually incinerated.°
(.27M364) - 98 3 tons
d) Of that 98.3 tons mercury incinerated it is
estimated that 18 5% remains in ash and is deposited
in landfills.6
(.185)08.3) - 18 2 tons to landfills from incineration
ash
e) The remaining 81 5% or 80 1 tons of mercury is
volatilized and released to the atmosphere.^ 80 tons to air
f) The remaining 73% or 266 tons of mercury is deposited
directly into landfills. Total mercury to landfills
266 + 18 ~ 284 tons.
VI. Paint Industry and Paint Application
a) Total mercury to be used in paint industry,
estimated for 1974 is 460 tons.5
b) Assume a Davis emission factor of 5 Ibs mercury
per ton of Eg used in paint manufacture. Emissions are
(460 tons)(5 Ibs/ton)/(2000 Ibs/ton) = 1 1 tons
c) Assume a Davis emission factor of 65% of the
mercury used in paints is emitted within 3 years after
application. There were 327 tons of mercury used in
paint in 1971.1
d) Emissions in 1974 from paint produced in 1971
alone are (.65)(327) = 213 tons
e) Thirty-two percent of the mercury used in paint
manufacture is released directly to the water environ-
ment 3 ( 32)(450) = 147 tons
It is assumed that this 1967 data is still applicable.
No other information was available.
f) 4 2% of the total mercury used in paints is entered
into the environment through disposal of containers
and subsequent dumping into landfills7(.042)(460)=19 tons
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VII Catalyst
a) Seventy-five tons estimated to be used in 1974-
for use as a catalyst
b) The most recent information available to me on
the amount of mercury released by catalytic uses of
mercury is from 1967.
c) Assuming that this information is applicable to
1974 patterns of mercury discharge
*
(1) 11% is released into the atmosphere
from plants using mercury as a catalyst
( 11)(75) = 8 tons
(2) 39% is released directly into water from
plants using mercury as a catalyst (.39)(75)=29 tons
(3) The remaining 37 tons is unaccounted for.
Certainly some is contained in the products manu-
factured, but how much is unknown
VIII.Dental
a) Projected 1974- usage - 75 tons of mercury^
b) Assume a Davis emission factor of 1% during
preparation.1 (.01X75) - .75 tons
c) The FDA has estimated that 25% of the mercury
used in dental preparations are lost in particles of
amalgum which are scraped off the tooth or fall into
the mouth and subsequently spit out into dental bowels
and hence to sewers.8
(.25) (75) = 19 tons
d) The remaining 74% is put into teeth and will be
considered as never entering the environment. Of course
some of this would get into the environment but in no
way could this amount be estimated with current infor-
mation.
IX. Agriculrure
a) Projected 1974 consumption for agricultural uses -
60 tons b
b) Assume a Davis report emission factor of 50% of
the mercury sprayed is emitted.-1-
c) Using a ratio based on 1969 data, 29% of the
mercury used in agriculture is sprayed
. (-29X60 X 5) - 9 tons emitted to air
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-7-
d) It is assumed that the remaining 51 tons are
released directly onto land and enter the environment
as pollutants.
X. Pharmaceuticals
a) Projected 1974 consumption 27.5 tons5
b) Davis report emission factor is U10 Ibs. Hg
emissions per ton of mercury used in anticiptics, skin
prep, and preservatives.^
(410 lbs/ton)(27.5)/(2000 Ibs/ton) = 5.6 tons
c) It is assumed here that the remaining 22 tons
is released into the aquatic environment via human
disposal and waste treatment plants.
XI. Paper and Pulp
a) Projected 1974 usage 11.5 tons5
b) From 1967 data compiled by David Klein3
(1) 60% of the mercury used enters the
aquatic environment
'(.6)(11.5) - 6.9 tons
(2) 40% is emitted to the atmosphere'
(.4X11.5) = 4.6 tons
XII Laboratory Uses
a) Most recent figure for annual consumption is
from 1968. 69 tons It is assumed that this figure
is applicable to 1974.7
b) Assume that 10% of the mercury consumed in the
laboratory is lost to the atmosphere.1
( 1X69) - 6.9 tons
c) From 1967 data 62% is lost to the aquatic
environment.3
(.62X69) = 43 tons
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XIII.Animal Manure
a) USDA estimates that 50% of all animal manure
is recycled and 50% is released directly into the
environment °
b) Total tonnage of feed grains produced in the U.S
was 282,500,000 tons.
c) Using .142 ppm as an average mercury content
figure-11
(.142X282 5) = 40.1 tons Hg
d) Assuming that 97% of the total amount of mercury-
ingested by animals eating feed grains is emitted in
waste
( .97)(40.1) = 39 tons
amounr released to environment (.5) (39) =. 19.5 tons
e) It is assumed that at least .5 tons are released
annually by other animals therefore upping the tonnage
to 20 tons/yr of mercury released into the land environ-
ment
f) It is assumed that 100% of the wastesnot collected
enter directly into the land environment ___ ~- __ ---
XIV Incineration
a) Using an estimate of 30,000,000 tons of wood and
paper products incinerated annually with an average
Hg content of .9 ppm.
(30)( 9) = 27 tons
b) Assumed that 100% of the mercury is volatilized.
XV. Sewage Plants
a) David Klein has reported i
influent Hg concentrations ranging from .6 to 27 ppb.
and from 5 to 3 ppb in effluents from 13 plants in
Wisconsin 12
b) Using an effluent concentration average of 1 ppb
the annual discharge of mercury amounts to 1000 Ib/yr
per million people served by the plant.
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-9-
c) For estimation purposes we will use 1 ppb as
being the national average of mercury concentration
in sewage effluents
d) Using 250 million as the population of the U S.,
and mercury discharges of 1,000 Ibs/yr per million
people
(250X1000)
(250X1000 lbs/person)/(2000 Ib/ton) = 125 tons
Sludge
a) Assume 35% of all dried sludge in incinerated
and 65% is deposited in landfills
b) An EPA task force indicated in 1971 that the
average mercury content of dried sewage sludge is
4 . 3 ppm .
c) In 1971, 1,022,000 tons of dried sewage sludge
were incinerated Assuming 100% volatilization and
0% collection of this mercury the total atmospheric
emissions from sludge incineration was-
(4.3X1.022) = 4.4 tons
d) If 4.4 tons of mercury is 35% of the total amount
of mercury tied up in sewage sludge then the total
contribution from sewage sludge of mercury to land
was- 8.2 tons .__-_
XVI. Lamps and Tubes
a) 1971 projected usage - 312.5 tons^
b) Assume a Davis emission factor of .4% Hf is
emitted to the atmosphere during manufacture.1
( 04X312 5) = 12.5 tons
c) 300 tons are available for recycling
d) Of the 300 tons available for recycling 52%
is actually recycled and the remaining 48% goes to
landfills.
(.48X300) = 14^ tons to landfills
XVII.Controls
a) Projected 1974 usage - 105 tons of mercury.
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b) Assume a Davis emission factor of .4% of the Hg
is emitted to the atmosphere during manufacture 1
(.04K1Q5) = 42 tons
c) 100 8 tons are available for recycling
d) Of the 100 8 tons available for recycling 52%
is actually recycled and 48% goes to landfills.
(.48)(100 8) = 48 tons to landfills
\
XVIII.Other
a) Projected 1974 mercury consumption 156 tons
b) Assume a Davis emission factor of 1% loss to
the atmosphere.1
c) 154.4 tons available for recycling
d) Of the 154.4 tons available for recycling, 52%
is actually recycled and 48% will be assumed to go
to landfills
( 48) (154 4) = 48 tons to landfills
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References
1. Roy, Sims L "Emissions of Mercury in the U.S.
by Source Category", 1971.
2. U.S Bureau of Mines, Minerals Yearbook, 1970,
Volume II Area Reports Domestic
3. Klein, David, "Sources and Present Status of the
Mercury Problem" 1971.
4. Battelle Memorial Institute, "Reported Mercury
Discharge from Chlor-Alkali Plants in the U.S." 1973.
5. Garrett, David, "1974 Mercury Input/Output Balance"
2/26/74
6. "Transport of Heavy Metals From Dry Batteries" 1970
7. Pacific Northwest Laboratories, "Criteria Document
for Mercury", November 1973.
8. Lambou, Victor, "Report on the Problem of Mercury
Emissions into the Environment of the United States. '
January 27, 1972.
9. Dr. Calvert, United States Department of Agriculture
Telephone Conversation, April 10, 1974.
10 Stanford Research Institute, Chemical'Economics
Handbook, 1974
11 Table 19, Estimate of Potential Human Exposure to
Mercury in the United States. 1974
12. Klein, David, "Mercury in the /Environment", May, 1973
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SLUDGE
ANIMAL MANUBE -
FOSSIL FUEL ASH
IWCL: BATTERIES,
TOES, SWITCHES,
T6
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FOSSIL
FUEL
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LAND
CULOR-ALKALI PLANTS
623
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DENTAL
PUA2MACEUTICALS
EWASE PLANT EFFLUENTS
12
LAS USE
CHLOR-AUALI PLANTS
CATALYST
PHARMACEUTICALS
DENTAL
PAPER £ PULP
7.4
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-------
MEATS, EGGS,
DRINKING WATER
AIR £ BBSS
SEAFOOD
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ET"
1
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(in UCL)
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PRINKING MEATS EOSS SEAFOOD OTHEBS TOTAL
WATE^ ,307 .03 31.5 24.48 64.365
7,900
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TO IN TUE RAPP f/LE)
MAX MEDIAN TO
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TRANSPORTATION EQUIPMENT
MEASURING, ANALYZING ANP CONTROLLING
INSTRUMENTS
ELECTRIC, GAS ANP SANITARY SEW/CES
BUSINESS SERVICES
EXECUTIVE, LEGISLATIVE /WP GENERAL
GOVERNMENT
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467
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MARCH 1974
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