STATES ENVl.'iONV.ilNTAt. PRCTCCTiON AGENCY
      Serious Ir.vestiqat'fon of 15 ChemicalSj

••ROM-  Kenneth L.  Johnson
      Acting Assistant Administrator, for Toxic Substances  TS-73S

  TO;
      Assistant Administrators
      Director, GRIG

           The  Office  of Toxic Substances has  prepared  a draft  status  assessment
      of available .information concerning  ihe'15  chemicals  for  which
      Administrator Costle  has publicly  announced a  serious  ihvestiaaticn
      during the  next  year.   Regulatory  actions on many of  the  substances  are
      likely to result from  the  investigation.

           I  would appreciate  your  review of-this-attached  draft material.
      If you possess information  which can  be  used to make  the  draft more
      complete, please include the  information as  it is received.  Dr. I.E. l/allen,
      of the Office of Toxic Substances, has been  designated to coordinate this
      information development  effort.  Your  comments may be'sent directly
      to him.   We plan  to share all  information during  the  next few months
      as gathered internally,  from other agencies and'.in international coopera-
      tion,-"in  order that fu'iT chemical management action may be considered.

          For  purposes of information sharing you may wish to designate a per-
      son or persons in your office as c contact point for Dr.  i'/aller,.  We'will
      duplica.e and distribute major papers and other documents.

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                                                                         0239,5
                             ACRYLOtilTRILE


Statement of Concern

In January 1977, the Manufacturing  Chemists  Association  released  the midpoint
results of a two-year study showing that  high  levels  of  acrylonitrile  incor- .
porated into the drinking water of  rats used in  the experiment caused  lowered
body weight, changes in the gastric epithelium,  tissue masses in  the ear duct,
and central nervous system lesions.  In May  1977,  DuPont reported  preliminary
findings of increased cancer incidence and mortality  at  a textile  fibers plant
where workers v/ere exposed to acrylonitrile.  Both studies are scheduled for
completion in early 1978.

Health and Ecological Effects, Environmental Behavior

Preliminary results of a survey of  workers at  a  DuPont plant which used
acrylonitrile indicate that cancers were  .2.5 to  3  times  the expected rate
among the employees who had worked  in that part  of the plant beginning 20  or
more years before.  Cancers of the  lung and  large  intestine predominated.
Further efforts to follow up on employees no longer with the company and the
gathering of other etiological data, such as on  smoking  habits, will be needed
before the full meaning of the data can be assessed.

The MCA is sponsoring three studies-of the oral  and inhaled toxicity of
acrylonitrile.  Dow is the researcher in  all thre,e tests.  In pregnant rats,
25 mg/kg/day of acrylonitrile administered by  ga&gj^increased teratogenic
effects, particularly skeletal and  circulatory anomalies.  The dams themselves
demonstrated a variety of toxic effects at 65  mg/kg,  such as reduced weight
gain, increased liver/body weight ratio,  and gastric  thickening.   In the two-
year drinking watei*"study, 12-month results  indicate  increased occurrence  of
subcutaneous maranary masses in females, masses in  the ear canal,  hyperplasia
and polyps of the stomach, and lesions in the  central nervous system,  particu-
larly in the high-dose groups.(300  ppm).  The  full significance of these find-
ings will be determined when the study is completed in early 1978. The two-
year inhalation study is about half completed, and data  are also  due to be
available in early 1978.  Preliminary findings show similar effects by inhala-
tion as from ingestion in water.

Acrylonitrile is highly toxic and can be  absorbed  through intact  skin, by
inhalation, and by ingestion.  It possesses  many of the  characteristics of
poisoning by cyanide, but studies have shown it  to be the compound itself,
and not the liberated cyanide, which causes  the  toxicity.  The toxicity by
other routes of administration has  been  studied.  Orally, the LD'gQ in  the
mouse is on the order of 35 mg/|(g;  in the rat, about  78  mg/kg; and in  the
guinea pig, about 90 mg/kg.  Acrylonitrile  is  known to  be a severe skin and
eye irritant.                                               ,  •

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                                   -2-
Aquatic studies have shown a LD-jg0 -  24  hours  at  100  rng/1  for  fish.   In
aerobic treatment systems, studies have  shown  that  it exhibits negligible
oxygen utilization and the dehydrogenase response indicates  that  it  had  an
inhibitory effect initially on the microbial  population.   The  standard cyanide
analytical test methods for water measure are  liberated  cyanide (cyanide ion)
and not the organic cyanides.   At the present  time,  there  are  no  standard
analytical tests for acrylonitrile or for the  other  organic  cyanides.

Sources, Environmental Levels, and Population  at  Risk

Acrylonitrile is used as an intermediate in the production of  a v/ide variety
of acrylic fiber plastics and  elastomers.

The largest use of acrylic fibers is  in  wearing apparel  and  carpeting and  it
is used in blankets, draperies, upholstery, wigs, man-made furs,  sand bags,
and industrial cloth.  AB5 (acrylonitriVe-butadiene-styrene) resins  are  used
in automobiles, applicances, and piping.  SAN  (styrene-acrylonitrile) resins
are used in automobile panels, battery cases,  tumblers and filaments.  Nitrile
elastomers (copolymerizing with butadiene) are used  in steals,  gaskets, hoses,
belts, adhesives, can closures, footwear,  and  brake-linings.

It is used as an intermediate  in the  manufacture  of  adiponitrile,  and acryla-   •
mide monomers, and polymers.  Adiponitrile is  one of the materials used  in
Nylon 66.  Acrylamide polymers are primarily used in  manufacturing chemicals
for water and waste treatment  processes.  Other polyacrylamide uses  are  for
papermaking strengthened and  retention  aids,  drilling mud additives, textile
treatment and surface coatings.  Nitrile barrier  resins  are  being  test-marketed
for making beverage and food containers.  Other uses  for acrylonitrile are as a
grain fumigant, an anti-stall  additive for gasoline  (Dow Ambifal  200), and for
other industrial ch'emicals.

In 1973, it'was the 50th largest chemical  produced,  1.353  billion  pounds, which
was up by 20 percent over 1972.  1974 projected production was 1.55  billion
pounds.

At the present time, there are four companies  producing  at six locations.
Exports have been decreasing each year as foreign capacity comes  on  stream.

The amount of by-products produced from acrylonitrile production  is  estimated
to be 150 million pounds each  for acetonitrile and  hydrocyanic acid  in  1974.
Both of these materials are highly toxic by all routes to  man, and are  toxic
to all species of aquatic life.

Although monitoring data are not available, there is predicted wide-spread 'low
level exposure to acrylonitrile.

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                                   -3-


All polymers contain some unreacted monomer and oligomers (incompletely
polymerized material), the amount depending on the conditions used in
polymerization and subsequent processing.   These unreacted materials are
slowly released during use and disposal  of the final  products.   Since many
fabrics contain acrylonitrile, and since acrylonitrile can be absorbed
through intact skin, there is a potential  hazard of direct exposure based on
unreacted monomers.  In addition, unreacted monomer is probably leached
during laundering, thus creating a v/ater pollution problem.  The presence
of residual acrylonitrile in polyacrylamide used for v/ater treatment is an
additional potential source of water pollution.  Further testing to determine
unreacted monomer levels is needed.

Additional hazards result from the disposal of acetonitrile and HCN, by products
from the manufacture of acrylonitrile, and the-production of HCN resulting from
improper incineration of acrylonitrile products.

Technical and Economic Considerations

The economic impacts and technical feasibility of controls cannot be estimated
because information to determine regulatory approaches is not yet available.
These data should be available later in the year.
 i

Regulatory Action in Progress,

OSHA has established the threshold limit-value of 45 mg/m^ as a workplace
exposure standard.r~A downward revision of the standard is under consideration.
NIOSH is preparing documentation for use in this effort.

The Food and Drug Administration has regulated'the unreacted monomer content of
nitrile rubber that comes into contact with food at 11 ppm, and has proposed a
ban on plastic soft drink bottles made of acrylonitrile.

Acrylonitrile used as a grain fumigant is being considered for rebuttable
presumption proceedings under FIFRA.  The substance is also registered under
the gasoline additive provisions of. the Clean Air Act.

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                                 ARSENIC
 Statement of Concern

 In 1975)  OSHA proposed a strict standard  for workplace  air  exposure  limits  to
 inorganic arsenic.   .Earlier EPA sampling  had found  that atmospheric  concentra-
 tions near two copper smelters exceeded the proposed  limit  (Anaconda,  Montana;
 and Tacoma, Washington) and closely approached  it at  three  other  smelter  sites.
 Results of an EPA-sponsored pilot epidemiology  study  near an  arsenical  pesti-
 cide plant in Baltimore reveal lung cancer rates  several times  the national
 average.   A number of arsenical compounds are being considered  for rebuttable
 presumption proceedings under FIFRA/FEPCA.   The Cancer  Assessment Group of  EPA
 has confirmed the carcinogenicity of inhaled arsenic.

 Health and Ecological Effects, Environmental Behavior

 Liver, skin, lunq, and lymphatic cancers, and adverse effects on  the thyroid
 gland have been reported in epidemiological studies of  occupationally exposed
 individuals.  The main threat of arsenic  as a carcinogen is inhalation of the
 inorganic forms.   A preliminary mortality study of the  population surrounding
 Allied Chemical Company's arsenical pesticide plant in  Baltimore  revealed a
 lung cancer rate sixteen times the national average.  A orevious  study has
 shown that retired workers from this plant suffer from  lung cancer at a rate
 seventeen times the national average.   A  Dow Chemical Company study  indicated
 an excess of lung and lymphatic cancers among their workers who had  been  ex-
 posed to arsenical compounds.  Arsenic occurs in two  forms:  trivalent and
 pentavalent.  Inorganic trivalent arsenical compounds, are much  more  toxic than
 pentavalent, botfracutely and chronically.  Pentavalent arsenic is often  found
 in metallo-arsenicals, and is of concern  because it can degrade into the  tri-
. valent form.  A study of workers at the Tacoma  plant  of ASARCO  has  shown  that
 neural conductivity in workers is altered as a  result of exposure to arsenic.

 A 1972 outbreak of arsenic poisoning i'n Getchell, Nevada,, is attributed to
 stack effluent from a gold smelter.  Studies made abroad have suggested that
 arsenic may be a skin carcinogen when ingested  in drinking  water at  levels as
 low as 0.3 mq/1.  The debate over the carcinogenicity of arsenic is  largely
 due to the fact that the animal studies conducted to  date  have  not  shown  a
 relationship between ingested arsenic and cancer.  Recent studies have shown
 that organic arsenical compounds produce additional toxicological problems.
 For example, Carbarsone has been reported to produce  liver  cancer in trout
 through ingestion (480 mg/100 g diet).

 Trivalent arsenic oxide is particularly  toxic to legumes and other crop plants.
 Depending on the soil type, 6 ppm arsenic can cause a 50 percent growth reduc-
 tion.  Phytotoxic levels of arsenic have been found as  far as two miles from
 the Tacoma smelter.  Once combined in soil, arsenic is  extremely persistent.

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Sources. Environmental Levels, and Population at Risk

Inorganic arsenic is emitted to the air from several  sources, including copper,
lead, and zinc smelters, glass production plants, coal-burning facilities,
cotton gins, arsenical -compound (including pesticides) production plants,
and pesticide application.  Organic arsenic discharges are associated with
the manufacture and use of pesticides.  Trivalent arsenic occurs naturally,
is a common contaminant of ores, and is the major component of arsenic
emissions from smelters.  Based on EPA estimates, the 15 copper smelters
contribute most heavily to air emissions of inorganic arsenic.  The Anaconda
copper smelter in Montana, and the ASARCO copper smelter and arsenic plant in
Tacoma, Washington, have been identified as having the highest arsenic emis-
sions.  Other industrial sources generally emit less  arsenic than copper
smelters.  Air levels in most urban areas for 1973 and 1974 were at or below
the level of detection [0.001 ug/m3).  Levels in areas near smelters ranged
from 0.003 to 4.86 ug/m3.

The land disposal of arsenical wastes can become a long-range public health
hazard.  A good example is Perham, Minnesota, where eleven people were poisoned
by contaminated well water in 1972.

A 1975 survey of drinking water supplies showed that  about one percent
'exceeded the interim drinking water standard of 0.05  mg/1.  Trivalent arsenic
is found at high levels in some groundwater.  Underground injection of
arsenical pesticide wastes in Philadelphia has contaminated a nearby stream
which is being considered for use as a drinking water supply.
      new technologies for energy production have important arsenic implica-
tions.- Early data on coal gasification indicate that two-thirds of the
arsenic present is volatilized.  Oil shale exploitation and geothermal energy
development may also release large quantities of arsenic.

Technologic and Economic Implications

In general, particulate control measures (multicyclones, balloon flues, and
electrostatic precipitators) are used to reduce arsenic emissions.  Baghouses
offer the greatest potential for control, but have not been widely adopted
by the smelting industry because of high capital and maintenance costs. •
Costs and feasibility of emission controls will vary from plant to plant.
Significant control efforts are being planned at the ASARCO smelter in
Tacoma, and are underway at Anaconda.  Conventional water treatment technology
has  been shown to be effective in meeting the arsenic drinking water  standard.
Arsenic concentrations of 0.1 and 1.6 mg/1 in wastewater can inhibit  waste'
treatment by activated sludge and anaerobic digestion respectively.   Thus,
concentrations exceeding these levels can present an additional hazard  in
wastewaters subjected to these treatment methods.  Air and water pollution
control efforts normally result in a solid waste-or sludge.  At present these
materials are being stored, pending development of acceptable disposal
technologies.

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                                   -3-
Regulatory Actions in Progress

EPA is locating and monitoring arsenical discharges, and is conducting
several studies to determine the toxicity of various arsenical compounds.
Limited epidemiological studies are planned to help determine effect levels.
Studies have been initiated to determine control technoloaies and costs for
arsenic reduction, and an Air Pollution Assessment Pveport on Arsenic has been
prepared.  EPA is considering the development of regulations under the Clean
Air Act' based on the findings of the Cancer Assessment Group.  A review of
the use of arsenical pesticides has recently been completed, and research
into disposal techniques for arsenical -wastes is planned.  A scientific and
Technical Assessment Report is being prepared in EPA and will incorporate
the National Academy of Sciences study on health effects.

In November 1975, OSHA proposed a workplace exposure limit for inorganic
arsenic at 4 ug/m^ (8 hour).  After review of comments and hearinq trans-
scripts, that Agency expects to promulgate "a-standard in early fall of 1977.

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                          ASBESTOS
 Statement  of  Concern

 OSHA has proposed  "lowering  its workplace standard by a factor of ten on
 the  basis  of  recent epidemiological data suggesting wider spread health
 effects than  previously suspected.  A number of major commercial sources
 of airborne asbestos are  limited by EPA regulations.  The Aaency is
 investigating taconite and  other hard-rock mining operations, where
 asbestos is a major ore contaminant.  EPA's nationwide sampling program
 is showing levels  of asbestos fibers in water supplies, natural runoff,
 and  discharges from manufacturing and mining sites.  Serpentinite rock
 crushed and used in playgrounds and roadways has been found to be a
 major contribution to asbestos levels reported in the Washington, D. C.
 area.

 Health and Ecological Effects, Environmental Behavior

 Airborne asbestos  fibers  have been known to cause asbestosis, lung cancer,
 and  pleura! and peritoneal  mesothelioma.  OSHA cites a number of studies
 showing gastrointestinal  (GI)-cancer in workers exposed to asbestos.   In
 one  study  of  insulation workers in the United States, seven percent of
 deaths could  be attributed  to asbestosis, which on the average appeared
 about 20 years after first  exposure — the same latency oeriod as for
 most cancers.   Available  epidemiological data show that lung cancer is
 responsible for as much as  20 percent of all deaths among certain types
 of asbestos workers; mesothelicma, 11 percent; and GI cancer, 8 percent.
 .              f
 There are  few .vTany data on the dose-response relationships of asbestos
 fibers in  either air or water.  Effects of airborne asbestos are far
 better documented  than those of waterborne.  OSHA cited workers who had
 developed  mesothelioma at exposure levels below the previous standard'of
 5 fibers per  cubic centimeter in its recent proposal to reduce the level
 by a factor of ten.  There  is some evidence that asbestos diseases,
 including  mesothelioma, occur in families of workers exposed to asbestos
•at levels  presumed to be  much lower than direct occupational exposure.

 Asbestos fibers are extremely resistant to degradation in the environment.
 Thus far,  it  has been impossible to demonstrate adverse effects on plants.
 Some adverse  effects on animals have recently been reported.

 Sources, Environmental Levels, and Population at Risk

 The  United States  utilized  approximately 800,000 tons of asbestos fiber
 in 1974.   Asbestos products are widely used in the construction industry
 (asbestos-cement pipe, building and other construction products, and
 floor tile).   Other products  include friction materials (such as brake
 linings),  felt and paper, packings and gaskets, and fireproof textiles.

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                                   -2-
It has been estimated that £5 percent of the asbestos is tinhtly bound
in products and is therefore not as available to the environment as are
airborne and waterborne asbestos fibers generated in the mining and
milling of asbestos ore, manufacture and fabrication of asbestos products,
and disposal of solid wastes from these processes.   Asbestos was used in
spray insulation in buildings between 1950 and 1972.  This may become a
major source of environmental discharge as buildincs constructed during
this period are demolished.

Asbestos minerals are founc1 throughout the United States.  Significant
quantities of asbestos fibers appear in rivers and streams draininn
from areas where asbestos bearing outcronpinqs of serpentine rock are
found.  Some of these outcroppings are being mined.   Asbestos fibers have
been found in a number of drinking water supplies,  but the health implica-
tions of ingesting asbestos are not fully documented.  Emissions of
asbestos fibers into water and air are known to result from mining and
processing of some minerals.  Asbestiform-fibers in the drinkinq water
of Duluth and nearby communities at levels of 12 million fibers per liter
have been attributed to the discharge of 67,COO tens, of taconite tailings
per day into Lake Michigan by Reserve Mining.

Exposure to asbestos fibers may occur throughout urban environments.  A
recent study of street dust in Washington, D. C. showed approximately
50,000 fibers per gram, much of which appeared to come from brake lininns.
Autopsies of New York City residents with no known occupational exposure
showed 24 of 28 lung samples to contain asbestos fibers, perhaps resultinej
from asbestos from brake linings and the flaking of sprayed asbestos
insulation material.

Technologic and Economic Implications
                                                                     *
Coagulation treatment and filtration are necessary to remove contaminant
asbestos from water.  Filtraticn technologies for air, while meeting the
no-visible-emission standard, permit large quantities of asbestos fibers
to escape.  Fibrous glass has frequently been substituted for applications
requiring insulative properties, but there is some  debate over its safety.
For some other applications, such as brake linings,  economically feasible
substitutes may not be available.

There is no inexpensive, standardized analytical method for measuring
asbestos, and monitoring costs are very high.

Regulatory Actions in Progress

An air standard has been promuloated for a number of major commercial
sources of asbestos fibers.  Hard-rock mining and taconite beneficiation,
where as.bestos is an ore contaminant, are being investigated.  Effluent
guidelines have been promulgated under the Federal  Water Pollution Control
Act which,, together with the flPDES permit procram,  should reduce asbestos
discharges.

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                                   -3-
EPA is sponsoring an extensive national asbestos monitoring proqram.
Preliminary findings indicate that asbestcs is a widespread contaminant
of drinking water.  MAS is reviewing the implications of these preliminary
findings.  Reserve Mining has agreed to halt the discharge of taconite
tailings into Lake Superior.  Standard analytical methods are beinq
developed for both research and monitoring purposes.  A number of epidemi-
ology studies to further clarify the health risks of asbestos are beinq
sponsored by EPA.

In 1972, OSHA established a workplace exposure standard.  In October 1975,
OSHA proposed a further reduction in the level.  The National Institute
of Environmental Health Sciences (NIEHS) is conductina innestion experi-
ments to. clarify health hazards of this route of exposure; F.PA is partially
sponsoring these studies.  The results will be available in 1979.

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                                  BENZENE


Statement of Concern

Benzene, a component in gasoline and an important feedstock for the chemical
industry, has been the subject of numerous published reports linking leukemia
with worker exposure.  Large quantities of benzene are discharged into the
environment from automobiles, and probably from stationary sources.  NIOSH
has promulgated an emergency workplace standard which has been stayed by
court order.   EPA has listed benzene -as a hazardous pollutant under Section
No. 112 of the Clean Air Act.          -                .

Health and Ecological Effects, Environmental Behavior

Numerous fatalities from occupational benzene poisoning have been reported
since the early 1900's.  After inhalation ojr ingestion, benzene is absorbed
rapidly by the blood.  At non-lethal concentrations, a variety of human central
nervous system disorders are observed, depending upon .the extent of exposure.
These include euphoria followed by giddiness, headache, nausea and staggering
gait, as well as fatigue, insomnia, dizziness, and unconsciousness.  Observed
damage to the human blood-forming system includes anemia, reduction in platelet
numbers, and depression of the white blood cell count.

Chronic benzene exposure also has resulted in chromosome aberrations in human
lymphocytes.  * As early as the 1930's, benzene was suspected in cases of leukemia.
Available epidemiological data indicate that the compound does induce leukemia
although the data cannot be considered, to constitute unequivocal evidence that
benzene acting a'Tdne is leukemogenic.  Attempts by the National Cancer Insti-
tue and others to induce leukemia in animals with benzene have not been
successful.  Hov/ever, the results of inhalation experiments with mice, the
species most susceptible to leukemia, are not yet available.

Based on its vapor pressure and chemical stability, benzene is expected to be
quite mobile and persistent.  Adverse effects on ecological resources have not
been reported.

Sources, Environmental Levels, and Population at Risk

In 1973, over 10 billion pounds of benzene were produced from petroleum and
coal in the United States.  This volatile, colorless, flammable liquid is
used mostly for synthesis of organic chemicals.  It has been estimated that
at least 80 million pounds of benzene may be lost to the environment during  •
benzene production, storage, and transport, while as much as 650 million
pounds may be released during its use to produce other organic chemicals.
The latter figure was calculated from the difference between 100£ yield and the
reported yield in these reactions.  Therefore, this is only a crude measure of
the worst-case benzene emissions during usage.  Emissions are concentrated in
the Texas Gulf area and the Northeast.

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                                   -2-


It has been calculated that approximately one billion pounds of benzene were
released with hydrocarbon emissions from motor vehicles in 1971  in a aeo-
graphical pattern similar to population distribution.  Another 22-24 million
pounds of benzene may be released into the environment each year with spilled
oil.  Hydrocarbon emissions from non-transportation sources, such as coke
ovens and power plants, may also contain considerable amount of benzene.
Additionally, benzene is an active ingredient in a number of insecticides
and miticides, although the amount of release to the environment from this
source has not been calculated.         .

In an EPA study of organic compounds in the drinking v/ater of ten cities,
benzene was detected in water from four cities at concentrations ranqinq
from 0.1-0.3 ug/1.  Previous studies reported levels up to 10 uq/1.   Average
levels of benzene detected in air in a limited number of studies are in the
low ppb range with one high reading of 23 ppm reported in the vicinity of  a
solvent reclamation plant.  No data have been found on levels of benzene in
soil, wildlife, and fish.  Benzene is widely enough distributed that most
people are probably exposed to very low levels; the health implications of
this type of exposure are not known.

Technologic and Economic Implications

Reduction in organic compound emissions to achieve the National  Ambient Air
Quality Standard for oxidants should result in some reduction in benzene
emissions.  As a result of lead removal from gasoline, the average content
of aromatics, including benzene, in gasoline is likely to increase slowly.
However, hydrocarbon emission controls on motor vehicles should result in  a
net reduction in benzene emissions.

Regulatory Actions in Progress

In 1974 NIOSH published a criteria document for occupational exposure to
benzene which recommended adherence to the existing Federal standard of
10 ppm as a time-weighted average with a ceiling of 25 op'm,  OSHA has pro-
posed a reduction of the standard to a 1 ppm 8-hour time weighted average.
with a ceiling of 5 ppm over a 15-minute period.  An OSHA Emergency Temporary
Standard has been stayed, pending a hearing on a reguest for injunction.
NIOSH is conducting retrospective studies of benzene mortality and airborne
benzene levels in service stations.

EPA has initiated an air monitoring program which will determine benzene
levels in selected areas.  Qualitative results obtained to date indicate
widespread low-level benzene contamination.  Studies are in progress to
document the extent of hazard and the best regulatory apnroach under the
Clean^Air Act.  EPA has conducted a limited survey of drinking water supplies
in which benzene was identified in some samples, and has beaun a more

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                                   -3-
extensive survey which will seek out benzene as well as a number of other
pollutants.  Benzene has been designated a hazardous substance under P/IPCA,
and ocean dumping is already strictly regulated.   The Consumer Products
Safety Commission is awaiting the results of the National Academy of
Sciences study on the health effects of benzene,  and will determine if
action is appropriate when the results have been received.

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                               BENZIDINE


Statement of Concern

Benzidine, a known human carcinogen,  is used as an intermediate in the manu-
facture of a number of azo dyes for textile, leather,  and paper products.
In addition to the EPA concern over liquid effluent discharges containing
benzidine, recent research results suggest that some of the benzidine-derived
azo dyes may reconvert to benzidine in man or in certain environments.  A
major labor union (AFL/CIO) has expressed strong interest in any action
taken on benzidine.

Health and Ecological Effects. Environmental Behavior

For a number of years, the manufacture and use of benzidine have been associated
with a high risk of bladder cancer among exposed workers.  Many scientists
believe that tumors can result from ingestion, inhalation, or skin absorption
of benzidine.  A number of animal  studies have demonstrated the carcinogenic
potential of benzidine.  Mice, rats,  and hamsters develop liver tumors, and
dogs may develop bladder cancer as a result of exposure.  Such studies have
many deficiencies for estimating the risk to humans which is associated with
the levels of exposure to carcinogens likely to be encountered in the environ-
ment.

Free benzidine has been detected,in the urine of monkeys fed benzidine-derived
azo dyes, establishing a potential for reconversion of azo dyes to benzidine.
Metabolism of benzidine-derived azo dyes may be similar in humans.  Japanese
silk painters reportedly have a high incidence of bladder cancer, possibly
resulting from TTcking brushes and spatulas coated with benzidine-derived
azo dyes.  However, the carcinogenic!ty of such dyes has not been specifically
determined.

Industrial data indicate that benzidine entering a waterv/ay dissipates and may
be degraded by naturally occurring processes.  Confirmatory investigations
have not been conducted.  Other aspects of environmental behavior have not
been addressed.  It has been hypothesized that azo dyes can reconvert to
benzidine under certain undefined environmental conditions.

Sources, Environmental Levels, and Population at Risk

The three identified manufacturers (Allied, GAF, and Fabricolor) estimate that
they produce 45 million pounds of azo dyes annually from benzidine.  The dyes
are used by about 300 major manufacturers of textile, caper, and leather
products.  The largest manufacturer  (Allied) recently announced its intention
to phase out benzidine production. .

The principal environmental concern at benzidine production facilities has
been the amount of benzidine in the v/aste effluents discharged to publicly
owned waste water treatment works (POTW's).  However, the only discharge
measurements to date have been made by industry, which has contended that
discharges at any facility usually do not exceed one pound per day.  Benzidine

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                                -2-


is believed to be present in the sludge removed from industrial  pretreat-
ment plants.  The environmental adequacy of land disposal of these sludges
is unknown.  According to industry data, discharges from the POTW are
usually below the limit of detection.  However, there have been siqnificant
accidental releases to POTW's.  Levels of benzidine exceeding 5 mg/1 can
inhibit anaerobic digestion wastewater treatment processes.   Thus, concen-
trations above this level at the POTW present a problem to POTW's using
this process, and a possible hazard to the receiving waters.

Free benzidine is present in the benzidine-derived azo dyes.  Accordina to
industry, quality control specifications require .that the level  not exceed
20 ppm and in practice the level is usually below 10 ppm.  Industry has.
estimated a total environmental discharge at the 300 user facility sites
of 450 pounds per year or about 1.5 pounds per year per facility, assuming
all of the free benzidine is discharged in the liquid effluent.

No measurements have been reported for benzidine in ambient .air, surface
water, or drinking water.  Further, no measurements for free benzidine in
finished products containing azo dyes have been reported.

Technologic and Economic Implications

The principal liquid effluent  control technology currently being used is
the reaction of benzidine with nitrous acid.  While effective in destroying
benzidine, hazardous decomposition by-products may be formed.  Industry thus
far-has rejected carbon adsorption as uneconomical.  The costs of treatment
at  the benzidine manufacturing plants are of far less concern than at the
user plants.  ThUs",'there is a continuing industrial emphasis on reducing
the levels of free benzidine in dyes, which result from more complete
reactions and release less benzidine  into the environment.

If  limitations were imposed on benzidine production or use, the vacuum would
probably be filled by imported benzidine-derived dyes and substitute dyes.
However, some of the possible  substitutes, such as ortho-toluidine, are also
of  environmental and occupational  health concern.  Industry estimates that
adequate substitutes would be  three  to  five times more expensive.   In some
highly specialized uses, particularly for the halogenated benzidine dyes, a
technically adequate substitute may  not be available.

Regulatory Actions in Progress

The stringent work place standards required by OSHA because of  the  carcino-
genic nature of  benzidine reduce environmental discharges resulting  from
inadequate  house-keeping procedures  at  benzidine manufacturing  sites.

EPA proposed a toxic pollutant effluent standard  in December  1973,  and  is
planning- to  repropose such  a  standard and a pretreatment requirement during
the next few months.  The results  of current animal experiments  at  the  National
Center .for Toxicoloqical Research, addressing  chronic  toxicity,  carcinogenicity,
and metabolic behavior,  should be  available during the  next year  and a  half.
Benzidine  is also  being  examined  in  the expanded  EPA  drinking water survey.

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                             CADMIUM  (Co)


 Statement  of Concern

 As  evidence  emerges that  cadmium  levels  in the- environment may be increasing,
 concern mcurts  over the accumulation  of  this substance's  in  the body at low
 levels of  exposure.   Ccdmiurr., which is used ir. a variety  of  commercial and
 consumer products, is believed  to reach  man through a number of routes,
 particularly as a contaminant of  fish and other foods.  There is recent
 concern over the presence of cadmium  in  sludge which might reach the food
 chair, as a result of  leaching from disposal sites or use  as  a soil condi-
 tioner.  A proposed amendment to  the  Clean Air Act calls  for explicit EPA
 attention  by 1977 to  a possible air standard for cadmium.

 Health anc Ecological Effects,  Environmental Behavior

 Cadmium accumulates in the kidney cortex, where it can.cause damage to the
 renal tubules at levels on the  order  of  2CO ppm.  The results of autopsy
 studies show current  levels of  15-50  ppm in the kidneys of people over the
 age of 50  who were^not occupationally exposed; the higher levels generally
 reflect those found ir. individuals who f-cd been smokers.  Autopsy data on
 the occupationally exposed are  inconclusive because samples  have been too
 smal1.

 At  high levels  of Cadmium exposure, other effects, such as bcne brittling,
 heve been  observed, mainly in Japan,  where widespread occurrence of
 Itai-Itai  disease caused  nearly 100 deaths.  These effects resulted from
 an  estimated intake of 6CO ug/day.  The  average American  diet contains
 50-75 ug/day.  Keafvy  fish eaters  receive- a higher dose, but  well belov.
 the levels observed in Japan.   About  five percent of ingested cadmium is
 retained in  the body, and its biological half-life in humans is estimated
•to  be at least  15 years.

 Prolonged  exposure to cadmium dust can.cause emphysema.   Recent epidemiological
 studies indicate abnormally high  rates of several forms of cancer due to
 occupational  exposure.  Hypertension  has teen developed in laboratory animals
 after prolonged exposure  to low levels.  The presence of  cadmium ir. hurran
 fetal tissues during  prenatal life shewn thct the metal traverses the
 placenta.  Experiment! studies in laboratory animals have confirmed this
 observation  and have  also shown that  cadmium is a potsrt  teratogen.

 Cadmium participate in air falls  out  ir.to water and soils.   Plants take it
 up  from the  soil, and people anc'  animals ingest cadmium from these sources.
 Uptake from  contaminated  water  has net been so well documented; it is
 suspected  that  this is th& significant route of exposure  to  fish.

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                                -2-
Sources, Environire-ntal Levels, and. Population at Risk

Cadmium is procuced in conjunction with zirc refining.   Ir. 1974, the total
U.S. consumption of cadmium was about 6300, metric tons, at a cost of about
$8500 per metric ton.   Atoi.t one-thirc was fmportec*.   By 1?S5, demand is
expected to recch 9600 metric tons.  Of the total use in 1975, about 55 per-
cent went to electroplating, 21 percent tc plastic stabilization, 12 percent
to pigments, 5 percent to batteries, and 7 percent to a variety of other
uses.  Major grcv.-th is expected in the nickel-cadmium battery industry.

An EPA-sponscred study estimated that a total of 1800 metric tons of cadmiLn
were released tc the environment in 1974.   Of this, about 20 percent was from
zinc mining and smelting, via air, water,  and tailings; EG percent was from
such indirect sources as fossil fuel combustion, fertilizer use, and disposal
of sewage sludge; and 30 percent was from industrial  uses, such as resmelting
of cadmium-plated scrap, incineration of plastics containing cadmium, and
electroplating.

The major sources of huir.an exposure are food ar.c1 tobacco contamination,
while direct water and air intake appear to be very minor contributors.
Groundwater contamination as a. result of waste disposal, however, is
common.  The Food and Drug Acministrction marl.etbasket survey has been
identifying low levels of cadmium in moit composite class samples.  Thus,
virtually everyone i«  expcsed tc trace levels of cadmium.  Recent studies
indicate thct, in Sweden, cadmium concentrations ir. wheat, may t-e increasing
at a rate roughly proportional to levels of industrial  use.   Increasing soil
levels may result from airborne fallout, fertilizer use, sr-d cadmium ir.
irrigation waters":  Cadmium has te-en identified  in soils at several locations
at levels of 0.55 to 2.45 ppm.
               •                                    t
Cadmium levels of 1 to 10 ug/1 have beer, found in 42 percent of available
ambient water samples, with more then 10 ug/1 in four percert.  Fifty-four
percent of the samples did not contain measurable amounts.  The annual
release of cadmium to the air at cne copper1 smelter we.s estimated to be
250 tons per year.  Ambient air levels averaged  .021  ug/m3.  Soil levels
of cadmium were about 1.6 ppn:, between one arc! five miles from the smelter,
and were reflected by a\erage findings of 4.7 ppm in leafty vegetables.

Technologic and Economic Implications

Substitutes are or will soon be avaiUble for rrost tut net all electroplating
uses and for plastic stabilizer use et comparable cost and efficacy.

A cadmium level of 0.02; mg/1, has been shown to  inhibit wastewater treat-
ment by anaerobic digestion.  Should cadmium concertrations exceeding that
level reach a wastewater treatment plant using anaerobes, e hazard may be
presented tc the receiving water.  Trace contamination of air and water by
cadmium-is coiwion.  removal of such components is usually extremly costly.

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                                -3-
Regularory Actions i.n Progress

NIOSH is expected to submit a criteria document to OSHA this year at which
time the existing workspace standard will be reviewed.  The Food and Drug •
Administration has banned certain uses of cadmium pigments and cadmium-
containing materials.

Epidemiological studies are being conducted by the World Health Organization
to -determine whether cadmium may be a factor in hypertension and cardiac
disease in humans.  The National Cancer Institute is sponsoring studies to
investigate the carcinogenic potential of cadmium metal, cadmium oxide, and
cadmium sulfide.

EPA has prohibited the ocean dumping of cadmium, except as trace contamina-
tion.  The effluent guidelines for the electroplating industry address
cadmium released from this segment of'the economy, and hazardous spill
regulations include some cadmium compounds among the substances for which
spill penalties have been established.  An Interim Primary Drinking Water
Standard has been issued and pesticides containing cadmium are being reviewed
for possible Rebuttable Presumption Against Registration proceedings.  A
Scientific and Technical Assessment Report on cadmium has documented health
and technoloaical concerns for EPA.

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                       HEXACHLOROBENZENE

 Statement of Concern

 Despite the steps taken by several  States and several  companies to  reduce
 environmental  discharqes of hexachlorobenzene,  environmental  contamination
 persists.  Recent reports of the occurrence of hexachlorobenzene in human '
 adipose tissues (95 percent of those sampled),  the food supply,  effluents,
 drinking water, and pesticides (in  addition to  registered  pesticidal  use)
 add to earlier concerns of U.  S.  regulatory agencies.   In  1973,  EPA made  a
 public commitment in response to a  petition from the  Department of  Agricul-
 ture to set a  food tolerance for hexachlorobenzene.   Hexachlorobenzene  has
 recently been  shown to be a carcinogen in hamsters.

 Health and Ecological  Effects, Environmental  Behavior

 The death of breast-fed infants and an epidemic of skin sores  and skin
 discoloration  were associated with  accidental  consumption  of  hexachloro-
 benzene-contaminated seed grain in  Turkey in  the mid-19501s.   Doses were
 estimated at 50 to 200 mg/day for several  months to two years.   Clinical
 manifestations included weight loss,  enlargement of the thyroid and lymph
 nodes, skin photosensitization, and abnormal  growth of body hair.   Hexa-
 chlorobenzene  levels of up to 23 ppb  in blood are believed to  have  contributed
 to enzyme disruptions  in the population of a  small  community  in southern
 Louisiana in 1973.

 Long-term (up  to 3 years)  animal  ingestion studies  show a  detectable  increase
 in deaths at 32 pom,  cellular alteration at 1 ppm, biochemical  effects  at
 .5 ppm,  and behavioral  alteration between  .5 and 5 ppm.  Apparently,  the
 effective dosage"t"b offspring  is  increased by exposure, to  the  parent.   A
 12 percent reduction in offspring survival  results when exposure to very  low
 levels had been continuous for three  generations.  Teratoganic  effects  appear
.minimal.                                                 "

 A  recent  feeding study in  hamsters  showed  that  hexachlorobenzene causes
 hepatomas and  hemangioendotheliomas of'the liver.  Doses of 50,  100,  and
 200 ppm of hexachlorobenzene mixed with feed were used.  Hepatomas  were
 observed  at all  dose levels,  at rates  and  latencies appearing  to be dose
 related,  but not in the controls.   Hemanqioendotheliomas appeared only  in
 the high  dose  group (9?; in females, 342 in  males), and  three of  these tumors
 in males  gave  metastases.

 While  hexachlorobenzene appears to  have little  effect  on aquatic organisms,
 a  bioaccumulation  factor of 15,000  has  been demonstrated in catfish.  The
 chemical  is  toxic  to some  birds.  Eighty ppm caused death, and  5 ppm  caused
 liver-enlargement  and  other effects in  quail.   The half-life in  cattle  and
 sheep  is  almost  90  days.   Hexachlorobenzene is  very stable.  It  readily
 vaporizes  from soil  into the air; emissions to  air in  turn contaminate  the
 soil.

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                              -2-


Sources, Environmental  Levels, and Population at Risk

About 90 percent of the estimated 8 million pounds of hexachlorobenzene
produced annually in the United States is as a by-product at 10 perch! oro-
ethylene, 5 trichloroethylene, and 11  carbon tetrachloride manufacturing
plants.  Hexachlorobenzene is commonly detected in solid wastes and liquid
effluents.  Most of the remaining production is as a by-product at more
than 70 other sites producing chlorine and certain pesticides.   About
45,000 pounds per year are released into the environment during pesticide
use.  Hexachlorobenzene has also been  found in the waste tars from vinyl
chloride and other chlorine-product plants.

In 1975, forty-six percent of the soil samples collected at 26 locations along
a 150-mile transect in Louisiana v/ere  contaminated with HC3 at levels from  20
to 440 ppb.  Although water samples were generally below 3 ppb, one sample
below an industrial discharge contained 90-ppb.  Air immediately adjacent to
production facilities has shown concentrations from 1.0 to 23.6 ug/m^.   Most
of the hexachlorobenzene aopeared to be associated with particulates, but
low levels v/ere found in the gaseous phase as well, which might result from
volatilization from solid wastes.  Samples collected from pastureland near  a
known production site revealed concentrations in the vegetation fromf
0.01-630 ppm and in the soil from 0.01-300 ppb. £2  <2,*x> /«•          '
Hexachlorobenzene residues have been found in soil,  wildlife,  fish and food
samples collected from all over the world.  In the United States, residues
have been reported in birds and bird eggs collected from Maine to Florida,
duck tissues collected from across the country, and fish and fish eggs from
the East Coast ana Oregon.  Animal foods, including chicken feed, fish food,
and general laboratory feeds, have been found to contain residues.  The
frequency of detection of residues in domestic meats has been steadily
increasing since 1972, in part because of closer scrutiny.   The chemical
has been detected in trace amounts in only tv/o drinking water supplies.

EPA's monitoring of human adipose tissues collected from across the United
States reveals that about 95 percent of the population has trace residues,

Technologic and Economic Implications

If a food tolerance is established by EPA at about .5 ppm (the interim
tolerance), there is no reason to believe that substantial numbers of
animals or crops will be held off the market.  However, a level of .3 ppm
or lower would probably prevent the marketing of some products.  The
feasibility and costs of air emission and water effluent controls, particu-
larly the effectiveness of particulata reduction and of better housekeeping
practices, have not been estimated.  Effective incineration of wastes has
been demonstrated.  Proper landfill practice may serve this purpose; however,
studies- indicate that soil and other covers only delay volatilization.

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                                   -3-
Regulatory Actions in Progress

In the v/ake of widespread hexachlorobenzene contamination of cattle in
Louisiana in 1973, and concern over possible contamination of sheep in
California, EPA established an interim tolerance of .5 ppm.   Concurrently,
the State of Louisiana and several companies took immediate steps to tighten
up solid waste disposal practices from manufacturing.   Also, supplies of
Dacthal containing 10 percent HCS as an inert ingredient v/ere voluntarily
withdrawn from the California market.

As soon as the needed toxicologies! data are available, a food tolerance
will be established.   Also, all pesticidal uses will be reviewed, including
pesticides which contain hexachlorobenzene as a contaminant.  Studies of land
and other disposal methods have been completed.  Ocean dumping of hexachloro-
benzene -laden tars is prohibited.  Al-though not directly addressed by the
EPA permit program, provisions relating to suspended solids, and oil and
grease may provide some degree of control if hexachlorobenzene enters the
effluent stream.

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                         LEAD AND ITS COMPOUNDS
Statement of Ccncern

The carcinogenicity of several  lead salts has been demonstrated  in
laboratory animals; there is an absence of adequate human  data.   The
potential for lead poisoning in sensitive populations  is a majcr concern,
particularly in children, pregnant mothers,  and occupationally-exposed
workers in urban environments where elevated levels of lead in air,
dustfall, and soil represent significant additional sources of lead
intake.  A single episode of lead poisonina  in a child may result in  brain
damage rangir.g from subtle learning disabilities to extensive mental  hendi-
caps.

Health and Ecological Effects, Environmental Behavior

Clinical effects of lead poisoning may include acute and chronic certral
nervous system damage, peripheral neVve paralysis, kidney  damage, and
damage to blood formation processes which may lead to  anemia.  The  risk
of clear-cut clinical effects is greatest when blood lead  levels increase
above 80 ug/lOOg whole blood, and at lower blood levels when anemia
prevails.  Mild poisoning may be reversible  if exposure to lead  is
discontinued.  Maternal over-exposure may have greater toxic effects  on
the fetus" than on the mother.

Common sources of livestock lead poisoning include lead-based paints, storage
batteries, used motor oil and airborne lead contamination  of hay and  pasture
vegetation from smelting and other lead industries. A daily lead intake of
6-7 mg/kg body weight has beer, suggested as the minimum level which may
result, in poison-ing in cattle.  As much as two to three oercent  of the U.S.
waterfowl population may die annually from lead poisoning, primarily due tc
injestion of spent lead shot.

Sources, Environmental Levels, and Population at Risk

U.S. consumption of lead was 1.6 million short tons in 1974.  Major
uses included storage batteries (E2 percent), gasoline additives (16 percent)
pigments (seven percent), ammunitions (five percent),  solder (four percent),
and cable covering (three percent).  The elevated atmospheric levels of lead
in larger cities was attributed primarily to motor vehicle combustion of leaded
fuel additives.  About 180,000 tons of lead are emitted to air annually from
motor vehicle corr.bistion of fuel additives.   Other sources of lead pollution
include coal and fuel oil combustion, lead smelting, incineration of solid
wastes, and lead paints.

Lead levels in ambient air averaged 1-3 ug/m3 in urban areas, 0.1-0.5
ug/m3 in suburan areas, and less than 0.05 ug/m3 in rural  arees, except
in the vicinity of point sources and heavy traffic.  The levels  of lead
in natural waters and finished drinking water r&rely exceed 0.05 mg/1
except- in areas of lead ore depcsits and point source  discharges.

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                              -2-
The average daily oral intake of lead is estimated at 300 ug  for adults,
and 130 ug for children.   Childhood and infant pics has  resulted ir.
numerous cases of lead poisoninc, from the ingestion of peeling  lead  paint
and other lead-containing substances, and the inhalation of street dust.
Illicitly distilled whiskey and consistent consumption of game  animals
previously wounded by lead bullets or shot are potentially hazardous
dietary sources.

Occupaticnal health supervision has limited the magnitude of  industrial
exposures.  However, incidents of lead poisoning still occur  where medical
surveillance and exposure controls are inadequate; as recently  seen  in  an
auto battery plant in Visalia, California, and a pigments plant in
Beltsville, Maryland.

Technologic and Economic Implications

Substitutes are readily available for lead chromate pigments  in highway
pairts and for lead shot.  The economic impact of banning lead  chrcrnate
paint for highway markings would fall primarily on the producers of  lead
chrcmate.  The economic impact of actions to promote recycle  of lead
batteries should be minimal, -if any, since the rate of recycle  is currently
high, and the industry is willing to receive all used lead batteries it can
get.  EPA has specified standard methods for analysis of total  lead  in
water, and is currently considering methods for air and other tredia.

Regulatory Actions in Progress

The Food and Df-otj Administration has restricted the use of lead in paints
to less than 0.5 percent by weight for use on residential surfaces assessible
to^chilcren, has proposed a tolerance level (0.3 ppm) for lead  in evac&rated
milk and an action level  (7ug/ml) for Teachable lead in pottery and  enamel -
ware, and is considering limitations below 0.5 ppm for lead in  other canned
foods.  OSHA has proposed an action level of 50 ug/m3 and a permissible
exposure limit of 100 ug/m3 during an average eight hour work period for
lead and its compourds. The Consumer Products Safety Commission is currently
undertaking a review of the "safe" level of lead in paints.

EPA has established effluent limitation guidelines on lead discharges from
several industrial point scurce categories.  Fifteen lead compounds  have
been designated as hazardous substances.  Special care is required in ocean
dumping or other disposal of lead and its compounds.  Interim Primary Drink-
ing Water Standards set a maximum contaminant level for lead of 0.05 mg/1.

Pursuant tc Section 111 of the Clean Air Act, EPA has established standards
of performance for primary and secondary lead srr.eHs.rs.   Lead has been
added to the list of air pollutants under Section 108(a) of the Cle^n Air
Act, and the issuance of a national ambient air quality star-dard for lead
is plarned for the near future.

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                                -3-
Final  regulations promulgated on December 6, 1973, ccntrcl the amount of
lead additives in gasoline.  Lead levels in gas.oline muff; meet the
1.4 g/gal  limitation beginning October 1, 1976.

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                             MERCURY

Statement of Concern

     Despite recent action by EPA to limit mercury discharges  during
sludge incineration and through pesticidal use,  and earlier Anency
efforts to control  air emissions and liquid effluent discharges,  mercury
continues to enter the environment.   While more  stringent enforcement  of
existing regulations should be helpful,  discharges of mercury  from
fossil fuel plants, especially those that have shifted to coal  from
other less contaminated fuels, leaching  of mercury from land-disposal
sites, particularly into ground water, and urban runoff,  are among  the
currently uncontrolled problems.

Health and Ecological  Effects, Environmental  Behavior

Mercury in many forms  is highly toxic to man and other living  things.   In
terms of toxicity,  mercury and its compounds can be divided into  three cate-
gories:  1)  alkyl  mercury compounds; 2)"  elemental mercury; 3) inorganic
mercury salts and phenyl and methoxy ethyl compounds.  Alkyl compounds,  parti-
cularly methyl mercury, are the most toxic.  Over 90 percent of ingested methyl
mercury is absorbed in the gastrointestinal tract, and its v/hole-body
biological half life is 70-90 days.   Methyl mercury is transported  in
blood cells to, and concentrates in, brain and other central nervous
system tissues where it can cause irreversible damage.  In addition,  it
can cross the placenta! barrier and cause abnormalities in fetal  tissues
and irreversible damage to the fetus at  levels that appear to  cause no
symptoms in the mother.  Elemental mercury, phenyl and methoxy ethyl
compounds, and inorganic mercury salts are far less dangerous  than  methyl
mercury, because Tefss'are ingested and the rates of excretion  are higher.

The Food and Drug Administration action  level of 0.5 pom of mercury for fish
and shellfish, both raw and processed, is based on a 30 ug/day maximum-intake
of methyl mercury.   This is one tenth of the 300 ug/day average intake result-
ing in a blood level of 0.2 ppb in adults, the lowest level at which neuro-
logical symptoms have been observed.

Mercury is readily transported to water  by leaching from soil  and fallout
from air; most forms of mercury in soil  and water can be biologically or
chemically transformed to methyl mercury.

Sources, Environmental Levels, and Population at Risk

     In 1973, United States use of mercury was slightly less than 1900
metric tons at an estimated cost of $<3800 per metric ton.  The chief uses
were for battery manufacture  (29.9 percent) and chlor-alkali production
(24.1 percent).  Use in 1965 had been approximately 2700 metric tons;, the
reduction of use resulted largely from a recognition of the hazards in use
of the substance.  In the period 1965 -  1973, several uses  (particularly as
preservatives and in gold recovery) were eliminated.  Mercury  is still used
to make oaints and industrial instruments.

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                                   -2-
NIOSH estimates that 150,000 workers are exposed to mercury.   Because  the
vapor is colorless and odorless,  overexposures can easily go  unnoticed until
symptoms appear.   Of a total of 1900 metric tons used,  it has been  estimated
that as much as 80 percent is discharged into the environment.   Distribution
of mercury discharges from man-related sources to the environment is about
31 percent to the air, 6 percent  to v/ater,  and 36 percent to  land.   Concentra-
tions in the various media are measured in  terms of total mercury rather than
the more hazardous methyl forms;  thus, the  data collected do  not represent the
true hazard.

Mercury is also a contaminant of  coal, and  may be a runoff problem  from slag
piles.  In addition, landfills are a source of leaching mercury;  this  problem
may be particularly severe in areas whare drinking water supplies are  drawn
from ground water.  Exposure to mercury is  widespread,  but inadequate
documentation of levels of methyl mercury makes estimates of  risk difficult.

Technologic and Economic ImpVjcatj_ons_

Because most mercury losses occur during the use and disposal of products,
recycling may provide the best method for reducing environmental  discharges
from batteries and instruments. 'Mercury emissions from the chlor-alkali
industry would still be significant, even if state-of-the-art controls
are applied to the production stream.  Diaphram-cell technology could
eliminate mercury emissions, but  might add  to problems  associated with •
asbestos and lead.  New developments in this technology are reducing use
of lead and eliminating asbestos; thus increased future reliance on new with-
out the added environmental burden. Diaphragm cells may offer the desired
reduction in mercury emissions.

Regulatory Actions in Progress

FDA has proposed an action level  for mercury in fish and shellfish. As
ff result of NIOSH recommendations, OSHA is  considering revised workplace
standards for inorganic and alky! mercury.

EPA has set a hazardous air pollutant standard for mercury under Section 112
of the Clean Air Act, and is considering New Source Performance Standards  to
require zero emissions of mercury from new chlor-alkali plants.

EPA has addressed the problem through effluent guidelines for a few industrial
categories and may expand this coverage in  the future.   The National Interim
Primary Drinking Water Standard for mercury is 2 ppb.  Ocean dumping is
tightly controlled.

The EPA recently ordered an end to. the registration of most pesticides contain-
ing mercury and particularly those used in paints, although the decision has
been stayed pending completion of judicial  review.

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                            PHOSPHATES


Statement of Concern

Phosphates, a nutrient necessary to plant life,  in excess  quantities
accelerate eutrophication of freshwater aquatic  systems, particularly
lakes— both natural and artificial.   Such an excessive nutrient  loading
creates problems ranging from discoloration and  obnoxious  odors  to  destruc-
tion of economically important freshwater fishes.   Although  effluent  guide-
lines have been established for certain phosphate-producing  activities,  they
have not been adequate to address eutrophication problems  which may result
from the non-essential use of phosphates, as example,  as detergent  builders
or in fertilizers.

Health and Ecological  Effects, Environmental Behavior.

Health effects on humans are limited to occasional outbreaks of  gastro-
enteritis, when certain blue-green algae whose growth  is promoted by  phosphate
loading are inadvertently ingested.  The chief human impacts are  on recrea-
tional and aesthetic values of lakes, value of lakeshore property,  and  costs
of water treatment.   Continued -depression of the commercial  fishing industry,
particularly in Lake Erie, is another economic impact.

Eutrophication is a  natural process of aging in  lakes,  normally  taking  place
over millenia.  Oligotrophic lakes receive little phosphorus nutrients,  and
thus do not support  many forms of life:  Over time, nutrients reach the  lake
from runoff, photosynthesis, and other sources in sufficient quantity to
promote growth erf-a  variety of plant and animal  species.   Over many centuries,
the phosphate levels will increase because of continued accumulation  from
land runoff and other factors, and the living species  present will  change.
Certain algal organisms may take over, form dense mats, die, and  decompose,
depleting oxygen supplies.  Other plant and animal life also dies,  decomposes,
and further depletes the oxygen, causing further destruction of  life.  The
lake may become murky, malodorous, and stagnant.  It generally becomes  swampy
and ultimately is filled in.

The addition-of phosphates from manmade sources  at abnormally hicjh  levels
(cultural eutrophication) accelerates the eutrophication  process  so that it
can occur within only a few years.  Artificial lakes,  such as water supply
reservoirs, appear to be susceptible to accelerated eutrophication.

Phosphates are-water-soluble, adhere to particulate matter,  and  thus  are
transported in runoff.  They are incorporated into plant tissues, and,  as the
plants die, phosphates tend to accumulate in the sediments.   There  is little
evidence of soil transport of phosphates, except in sandy  or gravelly soils.

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                                   -2-
Sources, Environmental  Levels,  and Populations Exposed.

Excess phosphates may reach lakes from land runoff,  industrial  or municipal
sewage, and agricultural  activities.   These substances are used in fertili-
zers and as detergent builders,  and are found in soft drinks,  beer,  animal
feeds, and a variety of industrial wastes.

Levels of phosphate phosphorus  in the Great Lakes range from 5 ug/1  in the
oligotrophic portions of Lake Superior to 61  ug/1 in Lake Erie.  Extensive
sampling of lakes has been conducted within the EPA  National Eutrophication
Survey.  Levels of phosphate phosphorus are of less  concern, per se_ than the
combination of factors which accelerate aging in the lake.

Because of the limited health effects which would be expected to result from
the intake of lake water, it is  more germane to discuss economic injuries as
a result of eutrophication.  Commercial fishermen,  businesses or supply equip-
ment for those activities are most severly affected  by the effects of phosphate
loading.  Excess nutrient enrichment is a problem of varying intensity in most
parts of the country and may continue to increase with population pressures.

Technologic and Economic Considerations.

Substitutes are available for detergent-builder applications;  however, the
relative cost and safety of those chemicals' is not well documented.   Sone
years ago, many of the detergent makers planned to substitute nitrilotriacetic
acid for sodium,tripolyphosphate (the most commonly used builder at the ti-.e.)
and then learned of evidence suggesting that nitrilotriacetic acid is a
carcinogen.  More recently, the  National Cancer Institute, the International
Joint Commission, and Canadian  agencies have undertaken health and environ-
mental studies of the effects of release of phosphates. • Results are expected
within the next few months.

Tertiary treatment technology can remove phosphate phosphorus from municipal
and industrial waste streams.  These systems are expensive, and create poten-
tial disposal problems with spent activated carbon columns and other filters.
Some secondary treatment methods commonly in use may provide adequate removal
of phosphorus from certain waste streams.

Treatment of drinking water taken from highly eutrophic lakes  is a difficult
and expensive undertaking, although the technology does exist.  Such treat-
ment reduces taste, odor, and color problems, but does not  resolve the excess
phosphate issue.

Phosphate phosphorus is an essential ingredient in fertilizer, no known
substitute will achieve the desired purpose.

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                                   -3-
Regulatory Actions in Progress

Effluent guidelines for runoff from feedlots, fertilizer manufacturing, and
phosphate manufacturing have been issued incorporating water quality criteria.
These guidelines govern permits issued to persons engaged in these businesses,
but the criteria are not designed to address accelerated eutroohication.

EPA's Regional office and the International Joint Commission have recommended
that Stat-es abutting the Great Lakes adopt a discharge level of 1 mg/1 of
phosphate phosphorus in effluents v/hich enter the-lake.

Four States have banned the use of phosphate detergents (Michigan, Minnesota,
New York, and Indiana).  Indiana has reported some success in reversing
eutrophicaticn damages in its lakes.  EPA has urged the Great Lakes States
to adopt similar bans.  Three Great Lakes cities also have adopted bans on
phosphate detergents.

EPA is studying phosphates to determine if regulations including a ban on
certain uses are needed either nationally or on a regional/conditional
basis.  Source and impact analyses are in progress.

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                          POLYBROMINATED BIPHENYLS
Statement of Concern
In 1973, one to two tons of polybrominated biphenyls, a highly toxic flame
retardant,were accidentally mixed into an animal  feed supplement and fed
to cattle in Michigan.  Contamination also resulted from traces of poly-
brominated biphenyls being discharged into the environment at the manufactur-
ing site and at other facilities involved in handling polybrominated biphenyls.
Dairy and cattle farms were quarantined, tens of thousands of swine and  cattle
and more than one million chickens have been destroyed, and litigation involving
hundreds of millions of dollars has been instituted.   Before the nature  of
the contamination was recognized, many of the contaminated animals had been
slaughtered, marketed, and eaten, and eggs and milk of the contaminated
animals were consumed.  Thus, large numbers of people were exposed to poly-
brominated biphenyls.  Commercial manufacture for  polybrominated biphenyls
distribution in the U. S. has been discontinued, but manufacture for export
continues.                                     •

Health and Ecological Effects, Environmental Behavior

Among the 10,000 people who have been identified as having consumed polybrominated
biphenyls, contaminated meat, milk products, poultry, and eggs, no overt symptoms
have been reported to date.  Health effects can only be extrapolated from
animal data.  Based on experimental data, polybrominated biphenyls may be much
more toxic than polychlorinated biphenyls.

Short-term rat, mice, and cattle studies have shown that polybrominated  biphenyls
may interfere withrrsproduction and liver functions, promote nervous disorders,
and react as a teratogenic agent in tissues.  Polybrominated biphenyls have
produced pathological changes in the livers of rats, mice, guinea pigs,  cows,
and rabbits.  In an experiment with guinea pigs, the chemical was demonstrated
to be an •imrnuno-suppressant agent.  About 400 cows given contaminated feed for
about 16 days exhibited anorexia, decreased milk production, increased frequency
of urination, some lameness, abnormal hoof growth, and shrinking of the  udder.
Later signs of toxic effects included bloody blebs, malformed or dead fetuses,.
abscesses, weight loss, and high susceptibility to stress.  Non-lactating cows
died within six months while the lactating animals survived and gradually
improved.  Massive liver abscesses were found in dead animals.

Studies at the University of Michigan medical school  have shown profound
adverse effects on the kidney, liver, and thyroid  in rats and mice.  Neoplastic
liver nodules appeared in rats.

Fish taken from streams known to have been contaminated by polybrominated
biphenyls have demonstrated that the chemical can  bioaccumulate to 20,000 to
30,000 times the ambient levels.  Polybrcminatsd biphenyls are believed  to
be quite persistent in the environment.  Polybrominated biphenyls readily
vaporize."

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                                   -2-
Sources, Environmental  Levelsvand Population at Risk

Polybrominated biphenyls have been used commercially as  flame  retardant  addi-
tives in synthetic fibers and molded thermoplastic parts.   Polybrominated
biphenyls have been incorporated into the plastic housings  of  many  commercial
products, such as typewriters, calculators,  and microfilm readers,  and con-
sumer products, such as radio and television parts,  thermostats,  shavers,  and
hand tools.

Michigan Chemical Corporation produced approximately 11  million pounds of
Polybrominated biphenyls from 1970 to 1974.   The White Chemical Corporation
produced approximately 100,000 pounds of the closely rented compounds,
octabromobiphenyl and decabromobiphenyl, from 1970 through  1973.   In  addition,
nine companies have been suppliers of laboratory quantities of polybrominated
biphenyls, each producing about five pounds  per year.  There is no  indication
of importation of the material.  Two plants  in New Jersey  produced  about one
million pounds for export in 1976.

Monitoring in the Pine River near the facility where polybrominated biphenyls
were produced indicated that levels diminished from 3.2 ppb in the  ambient
stream near the effluent discharge to .01 ppb eight miles downstream.  Fish
obtained in this eight-mile stretch had levels of .09.to 1.33  ppm.   In  the
New Jersey samples a level of 100 ppm was found in a sediment  sample, 10 to
60 ppb in receiving water, and 1 to 2.7 ppm  in the soils near  the two producing
plants.  Land-based plant samples showed 0.3 to 10 ppm and  aquatic  specimens
had 0.3 to 1 ppm.  Three of nine human hair  samples contained..03,  1, and  2  ppm
respectively.     if— '
                  *
Detailed data are available on levels found  in cattle and  hogs, with the highest
level detected being 2.27 ppm.  Data are not yet available  on  the levels found
in the 10,000 or more exposed persons.

Technologic and Economic Implications

Michigan Chemical Corporation reportedly had paid $20 million  in settling  a
$270 million suit, with claims of 5500 million still outstanding.  However,  the
financial dimensions of the incident are still not known.

Among the substitutes for polybrominated biphenyls are the  more expensive  deca-
bromobiphenyl oxide and several halogenated  aliphatic compounds.  However, the
environmental acceptability of these compounds has not been assessed.

Monitoring methods have been developed and are being standardized.

Regulatory Actions in Progress

The State of Michigan has been the focal point for responding to the contamina-
tion incident.  In addition, the Department  of Agriculture, the Food and Drug
Administration, the National Cancer Institute, the Communicable Disease Center,

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                                   -3-
EPA, the Michigan State University, and the University of Michigan, have con-
ducted a wide array of epidemiological, toxicolog.ical, analytical, and related
projects to clarify the effects of the chemical on humans and animals and to •
assess the extent of contamination.  The Toxicology Coordinating Committee of
the Department of Health, Education and Welfare is preparing a synthesis of
available health effects information.  EPA provides assistance in environmental
monitoring.

The Food and Drug Administration has set temporary action levels for poly-
brominated biphenyls in contaminated foods and in animal feed.  The State
of Michigan has issued warnings to sport fishermen along the Pine River.

EPA's studies to document the full scope of the-hazard and determine the
appropriateness of regulations under TSCA and other statutes are continuing.

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               POLYMUCLEAR AROMATIC HYDROCARBONS
Statement of Concern

Increased exposure to polynuclear aromatic hydrocarbons  and  other  air
pollutants has been implicated by some researchers in  increased  rates
of cancer, especially of the lung.  Over 30 polynuclear  aromatic hydrocarbons
have been identified as urban air pollutants,  including  several  carcinogens.
These chemicals are emitted during fossil  fuel  combustion,  in  natural  combus-
tion processes, and as a result of a variety of human  activities.   They  have
been found at low levels in liquid effluents,  some drinking  water  supplies,
and food.

Health and Ecological Effects. Environmental Behavior

Certain polynuclear aromatic hydrocarbons  which have been demonstrated as
carcinogenic in test animals at relatively high exposure levels  are being
found in urban air at very low levels.  Various environmental  fate tests
suggest that they are photo-oxidized, and  react with oxidants  and  oxides of
sulfur.  Because the chemicals are adsorbed on particulate matter, chemical
half-lives may vary greatly, from a matter of  a few hours to several days.
One researcher reports that photo-oxidized fractions of  air extracts also
appear to be carcinogenic.  Environmental  behavior/fats  data have  not  been
developed for the class as a whole.

It has been observed that polynuclear aromatic hydrocarbons are  highly soluble
in adipose tissue and lipids.  Most of the compounds taken in  by mammals are
oxidized and the metabolites excreted.  Effects of that  portion  remaining  in
the body at low levels have not been documented.

Benzo(a)pyrene, one .of the most commonly found and hazardous of  the polynuclear
aromatic hydrocarbons has been the subject of  a variety  of toxicological tests,
which have been summarized by the International Agency for Research on Car.cer.
As little as 50-100 ppm administered in the diet for 122-197 days  produced
stomach tumors in 70 percent of the mice studied.  A dose level  of 250 ppm
produced tumors in the forestomach of 100 percent of the mice after 30 days.
A single oral administration of 100 mg to nine rats produced mammary tumors
in eight of them.  Skin cancers have been induced in a variety of  animals  at
very low levels, and using a variety of solvents (length of application  was
not specified).  Lung cancer developed in 2 of 21 rats exposed to  10 rng/rr.3
benzo(a) pyrene and 2.5 ppm sulfur dioxide for 1 hour  per/day, five days a
week, for more than 'one year.  Five of 21  rats receiving 10 ppm sulfur dioxide
for 6 hr/day, in addition to the foregoing dosage, developed similar carcinomas,
No carcinomas were noted in rats receiving only sulfur dioxide.   No animals
were exposed only to benzo(a) pyrene.  Transplacental  migration of benzo(a)
pyrene has been demonstrated in mice.  Most other polynuclear aromatic hydro-
carbons compounds have not been subjected to testing.

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 Sources,  Environmental  Level, and Population at Risk

 Several  polynuclear aromatic hydrocarbons can be formed in any hydrocarbon
 combustion  process and  may be released from oil spills.  The less efficient
 the  combustion  process, the higher the emission factor is likely to be.
 The  major sources are stationary sources, such as heat and power generation,
 refuse  burning,  industrial activity, such as coke ovens, and coal refuse heaps.
 While polynuclear aromatic hydrocarbons can be formed naturally (lightning-
 ignited forest  fires),  impact of these sources appears to be minimal.  It
 should  be noted, however, that transportation sources account for only about
 one  percent of  production of these chemicals.

 Diesel  powered  vehicles produce more particulate emissions than gasoline
'powered;  the nature of  the fuel is such that the emissions would be expected
 to contain  greater amounts of polynucle~ar aromatic hydrocarbons, and limited
 studies have confirmed-this.  EPA has tested gasoline-powered passenger
 vehicles  to determine the amount of the chemical in the exhaust.  However, this
 characterization is of  particulates; little is known of vaporous components.

 Polynuclear aromatic hydrocarbons have been detected in urban water supplies at
 low  levels.  In  water and soils they are adsorbed en minerals or organic parti-
 culate  matter;  algae and invertebrates contain concentrations as high as 200
 times those of  the surrounding waters.  Levels detected in plants, on the other
 hand, are slightly lower than soil levels.  Sludge samples taken near a steel
 refinery  showed combined benzo(e)- and benzo(a)pyrene levels of 0.91-19.0 rag/kg
 (dried  weight).  Liquid effluents did not appear to contain these substances.

 Although  a  variety of these compounds have been observed in particulates from
 urban air samples, these are not routinely monitored.  Atmospheric concentra-
 tions are generally represented by measurements of benzo(a)pyrans concentra-
 tions.   In  heavily industrialized areas, benzo(a)pyrene levels have been as
 high as 20  nanograms (ng)/m3.  Urban levels are generally 2-7 ng/m3; and rural,
 0.3  ng/3.   In 1971-73,  nationwide annual emissions of benzo(a)pyrene were
 estimated at 900 tens.  It has been estimated that benzo(a)pyrene represents
 2-5  percent of  the total polynuclear aromatic hydrocarbons emitted frcm auto-
 mobiles;  a  similar and  as yet undetermined relationship may exist for stationary
 source  emissions.

 Because of  the  large number of sources, most people are exposed to very low
 levels  of the chemical.  Benzo(a)pyrene has been detected in a variety of foods
 throughout  the  world.   A possible source is mineral oils and petroleum waxes
 used in food containers and as release agents for food containers.  Studies of
 the  Food  and Drug Administration have indicated that no health hazard exists
 from these  sources.

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                                   -3-
Technoloqic and Economic Implications

Good participate emission controls can substantially reduce polynuclear aromatic
hydrocarbons emissions.  However, the costs that would be incurred in further
limiting polynuclear aromatic hydrocarbons emission from stationary and vehicular
combustion sources are not known.  The application of oxidation catalyst exhaust
treatment has been effective in dramatically reducing emissions from automobiles
when such systems are operating properly.  Similar controls at stationary sources
may have a similar effect.

Regulatory Actions in Progress

•Limitation of carbon monoxide arid hydrocarbon emissions from motor vehicles have
simultaneously and dramatically reduced the emissions.  A 1974 analysis of sta-
tionary source problems concluded that control-regulations designed specifically
for benzo(a)pyrene or polynuclear aromatic hydrocarbons were not warranted or
practical, but noted that compliance with existing regulations for incinerators,
open burning, coal combustion, and coking operations could significantly reduce
emissions.  Additional efforts to_document stationary source emissions, atmo-
sphe.ric chemistry, and human exposure have been initiated on a limited scale.
Consideration is being given to establishing revised standards for coke oven
emissions under the Clean Air Act.  EPA's Scientific and Technical Assessment
Report document and a National Academy of Sciences report have detailed much
of the hazard and technologic aspects of this class of compounds.

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                            TRICHLOROETHYLENE
 Statement of Concern

 Trichloroethylene has been  identified  by  the  National Cancer  Institute as-
 a carcinogen in laboratory  animals.   It  is  widely  used  for deqreasing of
 fabricated metals and,  to a lesser extent,  in cleaning  fluids.   In addition
 to extensive worker exposure,  it has  been detected in ambient air and water
 in industrial areas, in food,  and in  human  tissues.

•Health and Ecological Effects,  Environmental  Behavior

 Trichloroethylene induces tumors in mice  at high dose levels, predominantly
 liver cancer with some metastases (transfer)  to the lungs.   It  is absorbed
 rapidly by the lungs; only  a small amount is  eliminated by exhalation,
 58-70% being retained.   This is slowly eliminated  in the urine  as
 trichloroacetic acid or trichloroethanol.   Jhe first major review of
 trichloroethylene poisoning studied 284  cases, including 26  fatalities,
 in European plants where vapors were  inhaled.  Results  indicated that toxic
 action involves the central nervous system.  A number of short-term studies
 indicate that exposure to a concentration of  100 ppm in air'may interfere
 with psychophysiological efficiency.   In  one  study, six students exposed to
 110 ppm for' two four-hour periods separated by 1-1/2 hours showed significantly
 lower levels of performance in perception,  memory, and  manual dexterity tests.
 A confirmatory test using six workers in  a  plant using  trichloroethylene
 produced almost identical results. There is  a reported case of a man operating
 a metal degreaser who lost his sense  of  taste after one month's exposure to
 trichloroethylene concentrations which occasionally escaped  in  visible
 quantities.  Two-months later the same man  lost facial1  mobility and sensation,
 and developed electroencephalogram recorded changes which did not clear up
 during the following two years.
                                                                        «
 .Several incidents of workers being overcome by fumes have been  recorded.
 Also, people who sniffed trichloroethylene  have been reported as dying when
 exerting themselves shortly thereafter because it  acts  as a  cardiac sensitizer.
 As an example of the hazards of concern,  in April  1977, a worker at at  a
 General Motors plant was killed while attempting  to rescue a coworker who  had
 been overcome by methyl chloroform fumes  while removing residues from  a  cleaning
 operation.  Fifteen workers were hospitalized and  have  since recovered.

 Trichloroethylene frequently has been detected in  the  environment;  however,
 its behavior and transport have not been documented.  Adverse ecological
 effects have not been reported.

 Because of its low solubility, high vapor pressure, and high photodegradation
 rate at sea level (half-life in air is about  eight hours), trichloroethylene
 is not expected to accumulate in the  atmosphere.   Its  half-life in  water is
 on the order of months.

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                                   -2-
Sources, Environmental Levels, and Population at Risk:
Domestic production in 1974 was about 215,000 tons by five producers.  Over
90% is used for vapor degreasing of fabricated metals.  Ambient concentra-
tions in the atmosphere of industrialized areas have been estimated by
industry to be 2-16 ppt.  Water concentrations ars about 0.1 ppt.  The
character of the water was not defined, but trace amounts have been identified
by EPA in drinking water.  There have been several reports of contamination
of wells and groundwaters from careless disposal practices and accidents.

Over 20,000 workers are exposed to trichloroethylene.  The general public
may be exposed via inhalation of cleaning fluids and ingestion of foods,
spices, and medicines from which undesirable components have been removed
by trichloroethylene extraction.   In foreign studies, residues ranging from
0.02 to 22 ppt have been detected  in foods and concentrations of up to 32 ppt
have been detected in human tissues.  FDA is preparing to determine if the
compound can be detected in their  food monitoring programs.

Technologic and Economic Implications

Cold metal  cleaning,  vapor metal  degreasing,  and dry cleaning operations  present
different control  problems.   Both methyl  chloroform and  perchloroethylene are
being considered as possible substitutes  for trichloroethylene as degreasing
agents.   Both appear less damaging to  air quality,  however,  methyl  chloroform
may adversely impact the ozone layer.   All  three are comoarably oriced and,
since many users have already made this change,  the economic impact should
be minor.  Closed loop systems could permit recovery; however, this may reore-
sent a higher cq-s-t factor than the use of substitutes.  Preliminary studies
of the National 'Cancer Institute indicate that perchloroethylene may also
present health hazards.   Further studies are needed to determine if the
substitutes are acceptable.

Regulatory Actions' in Progress

In October 1975, OSHA proposed a reduction in the workplace standard, and is
reviewing the proposal, together with possible standards for methyl chloroform
and perchloroethylene.  MIOSH is preparing a hazard review to revise the 1973
criteria document.

Trichloroethylene oroducers have conducted eoidemiological studies, long-term
animal feeding studies, and long-term animal inhalation studies, and an  in-
depth literature survey has been completed for the Manufacturing Chemists
Association.

Since trichloroethylene contributes to photochemical  smog, State Implementa-
tion Plans provide a mechanism for limiting emissions.  Detailed health,
environmental, and economic analyses are being done  as a basis for determining
the necessity  for revisions to these plans.  Discharge permits limiting^
bacterial oxygen denand, chemical  oxyqen demand, and  suspended solids  also
provide  some control over effluent discharges.

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                                -3-
The National Cancer Institute will  begin testing trichloroethylene  in an
oral exposure study,  using their revised protocol.   Doses  are based on
levels resulting in 10 percent weight loss,  rather than lethal  levels.

EPA is conducting a detailed survey to determine if regulations are warranted.
The report is designed to collect the data needed to justify regulations using
TSCA and other authorities, if appropriate.

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