Introduction

Concern growing for decades over the condition of the environment and its effect on public health and the quality of life led to the passage of legislation in the 1970s to control environmental pollutants. The Environmental Protection Agency (EPA) was created in 1970 and given regulatory powers by the Clean Air Act Amendments of 1970 and the Clean Water Act of 1972 to set national air and water standards and to regulate hazardous pollutants. Since that time, both air and water quality have improved significantly (see prevalence data). The Toxic Substances Control Act of 1976 identified the need to control the risks of exposure to over 65,000 commercial chemicals. Complete information on health hazards exists for only about 2% of chemicals used commercially. Virtually all Americans have detectable tissue levels of DDT, dieldrin, PCBs and six other toxic chemicals. However, the proportion of the population with high levels of these toxic chemicals has declined steadily since the substances came under regulation in the 1970s. The Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980, known as "Superfund," recognizes the need to clean up the more than 23,000 potential hazardous waste sites in America. By 1986, work on 12 of the 541 sites on the National Priority List had been completed.

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The effects of low-level radiation from naturally occurring background radiation (80 millirems per year per person) and from medical X-rays (average 90 mrems per year per person) are not known. However, high doses of radiation (on the order of 100 rems) are known to be carcinogenic, mutagenic and teratogenic. While current regulations limit most occupational exposures to 5 rems per year per person, most Americans are exposed to 1/25 of that amount (200 mrems) or less. Recently, radon, a naturally occurring radioactive gas, has been recognized as a potentially dangerous source of radiation exposure and may result in more mortality to the general public than all other forms of radiation. ×Ö´®4

Prevalence ×Ö´®2

Toxic Chemicals ×Ö´®4

A 1983 National Research Council study identified 65,725 substances to which humans are exposed, including 3,350 pesticides, 3,410 cosmetics, 1,815 drugs, 8,627 food additives, and 48,523 commercial chemicals.

The National Toxicology Program lists 117 chemicals as potential human carcinogens.

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For 288 chemicals, evidence exists showing carcinogenicity in animals. For 30 chemicals or chemical mixtures and 9 industrial processes, there is evidence of carcinogenicity in humans. For an additional 63 chemicals or mixtures of chemicals and 5 industrial processes, there is evidence of probable carcinogenicity in humans. ×Ö´®7

At least 50 chemicals—including heavy metals (such as lead and cadmium), glycolethers, organohalide pesticides, organic solvents, and chemical intermediates (such as styrene and vinyl chloride)—that are in widespread use in industry have been shown to produce impairment of reproductive functions in animals.

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1,466 chemicals with possible cardiovascular effects are listed on the Registry of Toxic Effects of Chemical Substances by the National Institute of Occupational Safety and Health.

Hazardous chemical production in the U.S. in 1982 included 7,823 million pounds of benzene, 2,035 million pounds of acrylonitrite, 543 million pounds of asbestos, 952 million pounds of phthalate and 4,902 million pounds of vinyl chloride.

The usage of hazardous metals in the U.S. in 1982 included 1,303 million pounds of lead, 542 million pounds of chromium, 207.9 million pounds of nickel, 36.8 million pounds of arsenic, 82 million pounds of cadmium and 3.4 million pounds of mercury. ×Ö´®9

Over 50,000 pesticide formulations are registered with the Environmental Protection Agency. In 1984, 1.08 billion pounds of pesticide-active ingredients were used in the United States.

The National Human Adipose Tissue Survey showed that in 1983, more than 99% of the U.S. population had detectable levels of PCBs, DDT, DDE, dieldrin, hexachlorobenzene, trans-nonachlor, beta-benzene hexachloride, heptachlor epoxide and oxychlordane. ×Ö´®3

A national survey conducted from 1976 to 1980 revealed that approximately 675,000 (or 4% of) children between 6 months and 5 years of age have high blood-lead levels.

Removal actions are short-term EPA responses to prevent harm to public health or the environment. A 1984 EPA study listed the following substances found most often at removal actions: PCBs (at 23.3% of removal actions), pesticide (13.9%), heavy metals (13.9%), unspecified organics (9.3%), toluene (8.5%), cyanide (6.9%) and benzene (5.4%). ×Ö´®9

Air Contaminants

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The 1983 levels in the U.S. of 6 "criteria" air pollutants regulated under the National Ambient Air Quality Standards are: total suspended particulates, 48.7 ?m3 annual geometric mean; sulfur dioxide, 0.010 ppm annual arithmetic mean; carbon monoxide, 7.91 ppm annual 2nd maximum nonoverlapping 8 hr. average; nitrogen dioxide, 0.026 ppm annual arithmetic mean; and ozone, 0.141 ppm annual 2nd maximum daily 1 hr. average. ?m3 = micrograms per cubic meter; ppm = parts per million.

The national standards for sulfur dioxide, total suspended particulates, nitrogen dioxide and lead have been met almost everywhere in the nation. Carbon monoxide and ozone remain problem pollutants in major metropolitan areas.

In 1983, there was a national composite average of 11.4 days in which the level of ozone exceeded the standard of 0.12 parts per million. The composite average from 62 sites of the second highest daily maximum 1-hour ozone concentration was .146 parts per million.

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In 1983, the carbon monoxide national standard level of 9 parts per million over 8 hours was exceeded by a composite average of 7.7 days. The composite average from 62 sites of the second highest 8-hour carbon monoxide concentration was 9.07 parts per million in 1983. ×Ö´®7

Organic particulates account for 45% of toxic air pollutants; volatile organics, 30%; and metals, 25%, according to EPA estimates in 1984. ×Ö´®3

More than half of all air pollutants come from mobile sources (cars, trucks, airplanes, etc.).

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The pollution standards index (PSI) average for 23 metropolitan areas for 1981 included 0.13 days in the hazardous category (PSI higher than 300), 11.3 days in the very unhealthful category (PSI 200-300), and 33 days in the unhealthful category (PSI 100-200).

Eight toxic or hazardous air pollutants "which may reasonably be anticipated to result in an increase in mortality or increase in serious irreversible, or incapacitating reversible, illness" are listed under section 112 of the Clear Air Act. Those eight toxic air pollutants (and their health threats) include mercury (central nervous system damage), beryllium (berylliosis), asbestos (cancer), vinyl chloride (cancer), benzene (leukemia), radionuclides (cancer), inorganic arsenic (cancer) and coke oven emissions (cancer). In addition, sulfuric acid, which causes lung damage, is listed under section III for regulation by states.

A 1984 comprehensive assessment of air toxics by the EPA estimated that the additive lifetime individual risk of cancer due to simultaneous exposure to 10 to 15 toxic air pollutants in urban areas ranges from 1 in 1,000 to 1 in 10,000. It is estimated that as many as 1,600 to 2,000 cases of cancer may be caused annually by air pollutants. Approximately 440,000 cancer deaths occur annually in the United States from all causes.

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Water Contaminants ×Ö´®7

73% of the nation's rivers and streams and 78% of the nation's lakes and reservoirs were found to fully support their designated uses in a 1984 National Water Quality Inventory.

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The most commonly reported water pollutants in 1984 were, in order of frequency: bacteria, biochemical oxygen demand, nutrients, total suspended solids, toxics (pesticides, solvents, etc.), metals, acidity, salinity and ammonia.

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In 1984, the EPA reported detectable levels of volatile organic chemicals in 20% of small public water systems (less than 10,000 users) and in 28% of larger systems (more than 10,000 users). 4,000 private, public or industry water wells have been closed or affected by chemical contamination. ×Ö´®7

In 1984, 37 states reported elevated levels of toxic water pollutants (those pollutants with an adverse impact on human health or the aquatic environment at relatively low concentrations). The most widely reported toxic water pollutants reported in 1984 were, in order of frequency: PCBs, mercury, copper, chlordane, zinc, lead, cadmium, chromium and DDT. ×Ö´®9

Over 800 chemical compounds have been detected in the Great Lakes. Many of those compounds are known to be carcinogens, mutagens or teratogens in high concentrations in animals. However, the health hazards to humans from trace amounts of these compounds found in the Great Lakes are not known. ×Ö´®3

In 1982, 63% of the U.S. population was served by sewer systems offering secondary treatment or better. 10% had facilities with less than secondary treatment. 20% had on-site disposal systems and 7% needed sewage collection and treatment.

Approximately 117 million people in the U.S. (approximately 50% of the population) obtain their drinking water from ground water supplied by 48,000 community public water systems and 12 million individual wells. The remainder of the population receive their drinking water from surface waters of 11,000 public water systems. 1-2% of the nation's ground water is believed to be contaminated. ×Ö´®3

Hazardous Waste ×Ö´®5

Current estimates suggest that approximately 2,500 pounds of hazardous waste, as defined by the Resource Conservation and Recovery Act, are generated annually for each person in the U.S. A 1984 EPA study estimated that 264 million metric tons of hazardous waste are generated per year in the U.S.

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Of the 290 million tons of hazardous waste produced in the U.S. in 1981, 70% came from the petroleum and chemical industries.

An EPA inventory listed 23,488 potentially uncontrolled hazardous waste sites in February 1986. ×Ö´®1

A 1984 Office of Technology Assessment (OTA) report listed the following sources and amounts of hazardous waste disposed in 1981: 8.6 billion gallons per year (bgy) in 87 injection wells; 0.1 bgy in 70 land applications; 0.81 bgy in 199 landfills; 35.8 bgy in 1,078 surface impoundments; 0.4 bgy in 174 waste piles; 13.8 bgy in 2,031 underground storage tanks and 0.16 bgy in containers. ×Ö´®3

The same 1984 OTA report indicated that 14 million tons of hazardous waste are transported or transferred each year. ×Ö´®5

444 different toxic pollutants have been found by the EPA at hazardous waste clean-up sites. The 10 most commonly found substances are lead, trichloroethylene, toluene, benzene, PCBs, chloroform, phenol, arsenic, cadmium and chromium. Of these, 7 are believed capable of causing cancer; 7 of causing birth defects; and 5 of causing genetic defects. ×Ö´®2

5.1 million cubic feet of low-level radioactive waste is being produced annually in the U.S. from private and governmental sources.

The EPA estimates that the nation's 16,000 municipal sewage treatment plants produce 7 million dry metric tons of municipal sludge each year. The 500 sewage treatment plants of larger cities account for 3% of all sewage treatment plants, but produce 60% of the sludge.

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Disposal of municipal sludge is accomplished by the following means: land disposal, 54%; incineration, 27%; surface impoundment, 12%; ocean dumping, 7%.

Radiation

The general population in the U.S. is exposed to less than 200 millirems per year per person of low LET (linear energy transfer, i.e., gamma and X-rays) radiation. ×Ö´®1

It is estimated that the risk of low-dose radiation inducing a fatal malignancy is on the order of 1 in 10,000 per rem.

It is estimated about 3% of fatal cancers or 12,000 cases per year, can be attributed to exposures to ionizing radiation. ×Ö´®1

A nationwide survey in 1970 showed that 65% of the U.S. population was exposed to X-rays for medical or dental purposes that year.

In 1980, 1.3 million workers were employed in occupations in which they were exposed to radiation. 50% of those workers received no detectable dose. The average dose of those exposed was 0.23 rems.

Radon-222 ×Ö´®2

Radon is a naturally occurring radioactive gas of the uranium series that decays into 2 alpha-emitting, short-lived daughters. These substances can be inhaled and deposited in the bronchial tree, where they give off a carcinogenic dose of radiation. Exposure to radon decay products is measured by the unit Working Level (WL) or Working Level Months (WLM).

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Outdoor levels of radon decay products range from 0.0002 to 0.0004WL. The lifetime risk of developing lung cancer from exposure to those levels of radon is estimated to range from 2 in 10,000 to 4 in 1,000. ×Ö´®8

Indoor levels of radon are estimated at 0.005WL. The lifetime risk of developing lung cancer from this level of radon is estimated at 3 to 5 in 1,000.

Based on limited data, perhaps 1 million homes in the U.S. have radon levels that would result in a greater than 3 to 4 in 100 lifetime risk of lung cancer.

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Indoor radon decay products exposures in the typical range of 0.04-0.8 WLM per year may cause between 1,000 to 20,000 cases of lung cancer per year in the United States.

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Public Awareness ×Ö´®4

Increased public awareness of environmental issues is demonstrated by an increase of 250,000 (13%) in the membership of 11 environmental organizations between 1981 and 1983. ×Ö´®6

In a 1980-1983 study conducted by the National Research Council, it was determined that for 36% of the chemicals studied, no data were available to assess the extent of exposure; and for 75% of the chemicals studied, no information was available from which trends in exposure could be estimated. ×Ö´®5

The same National Research Council study showed that in order to make complete assessments of health hazards, further testing is necessary for 82% of drugs, 90% of pesticides, 95% of food additives, 95% of cosmetics, and essentially all commercial chemicals.

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Over 13% of cars built since 1975 have had their pollution control devices disabled.

Service Delivery ×Ö´®8

Since enactment of the Toxic Substances Control Act in 1976, the EPA has screened over 4,201 new commercial chemicals. In 1984, 1,192 new chemicals were reviewed through premanufacture notices by the EPA. 87% of these new chemicals completed the review without regulatory action, 3% were withdrawn due to concerns raised during their reviews, 4% were subject to formal regulatory action and 6% were awaiting resolution of issues raised in their review.

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According to a U.S. Department of Commerce analysis, the total national expenditure for pollution abatement and control in 1983 was $62.7 billion. ×Ö´®1

In 1983, industry in the U.S. removed 50,756,600 short tons of air pollutants and 27,175,000 short tons of water pollutants. ×Ö´®1

The quantities of air pollutants removed by industry in 1983, included 31,021.9 thousand short tons (tst) of particulates, 6,998.2 tst of sulfur oxides, 11,467.3 tst of nitrogen oxides, hydrocarbons and carbon monoxide and 1,269.2 tst of heavy metals, radioactive and toxic substances. ×Ö´®8

The amounts of water pollutants removed by industry in 1982, the latest year for which detailed information is available, included 12,522.3 tst of suspended solids, 3,435.5 tst of biochemical oxygen demand, 4,032.6 tst of chemical oxygen demand and 3,748.5 tst of oil, grease and toxic substances. ×Ö´®6

Under the Federal Motor Vehicle Control Program, the EPA sets national emission control standards and requires manufacturers to design new cars to meet these standards. The standards for new cars reduce emissions by about 95% for volatile organic compounds and carbon monoxide and 75% for nitrogen oxides.

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Lead gasoline additives used in transportation account for approximately 80% of atmospheric lead emissions. Unleaded gasoline was introduced in 1975 for cars with catalytic control devices. Sales of unleaded gasoline grew to 51% of total gasoline sales by 1982. From 1975 to 1983, lead consumption in gasoline decreased by 75%, resulting in a 67% decrease in average ambient lead levels.

In 1984, 28 states had automobile emission inspection programs and 8 more were expected that year.

The introduction of catalytic converters in 1975 contributed to a decline in carbon monoxide emissions from 81.3 million tons per year in 1973 to 69.7 million tons per year in 1979. ×Ö´®8

By June of 1983, 69% of the water treatment plants designated in 1972 as needed to comply with the Clean Water Act were already built. ×Ö´®6

By 1982, 70% of community water systems were doing regular bacteriologic analyses and meeting national standards for bacteriologic contamination, whereas in 1969, only 15% of community systems were believed to monitor routinely for bacteria.

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From 1972 to 1982, the United States spent $436 billion for pollution control, nearly $2,000 per person. However, total federal expenditures for pollution control are, in real value, 23% less than the 1979 peak and have fallen to approximately the level they were at in 1976.

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Significant Trends

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Toxic Chemicals

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Use of DDT was restricted in 1972; however, human adipose tissue sampling in 1983 showed that all Americans have detectable levels of DDT. From 1970 to 1979, DDT levels in human adipose tissue dropped more than 50% from an average of 8.2 to 3.5 parts per million.

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The percentage of the U.S. population with detectable levels of PCBs has increased from 85% in 1972 to 100% in 1983; however, the percentage of Americans with levels of PCBs greater than 1 part per million has declined from 50% in 1972 to 9% in 1983.

During the early 1970s approximately 200,000 metric tons of lead were used in gasoline. In 1986, it is expected that 4,000 metric tons will be used—a 98% decrease from the early 1970s.

A national blood-sampling survey showed a 38% decline in lead levels from 1978 to 1981.

From 1964 to 1984, the use of pesticides doubled from 540 million pounds per year to 1.080 million pounds per year. ×Ö´®8

Air Contaminants ×Ö´®9

In 23 major American cities, the average number of days in which the air is considered bad enough to cause any health risk has declined by 50% since 1974 to approximately 44 days a year.

From 1975 to 1982, ambient levels of certain air pollutants decreased by the following amounts: particulates, 15%; sulfur dioxide, 33%; nitrogen dioxide, no change; ozone, 18%; carbon monoxide, 31%; lead, 64%.

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Water Contaminants ×Ö´®6

The EPA estimates that from 1972 to 1982, industrial pollutants entering surface waters decreased significantly. Biochemical oxygen demand fell 71%; total suspended solids dropped 80%; dissolved solids decreased by 52%; oil and grease fell 71%; phosphate fell 74%; and heavy metals fell 75%.

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A comprehensive nationwide assessment of the nation's surface waters from 1972 to 1982 showed improvement of streams and estuaries, deterioration of lakes and reservoirs, degradation of 1.7 million acres and improvement of 0.4 million acres. ×Ö´®3

A nationwide study using the ability to sustain sport fish species as an indicator of surface water quality showed that from 1977 to 1982, the size of sport fish populations did not change in 91% of water; in 5% of waters, sport fish populations deteriorated; and 4% improved. ×Ö´®1

Hazardous Wastes ×Ö´®2

Trends in the generation, treatment, storage or disposal of hazardous wastes cannot be detected with any certainty. The disparity between a 1970 estimate of 9 million tons of industrial waste and the 1983 estimate by the Office of Technology Assessment of as much as 275 million tons results from differences in definition and increased knowledge about generators of hazardous waste.

Radiation ×Ö´®2

X-rays are the U.S. population's largest source of exposure to manmade radiation. The Center for Devices and Radiologic Health of the FDA estimated that the average absorbed-dose rate for the bone marrow of the adult U.S. population from medical X-rays increased from 83 mrads per year in 1964 to 103 mrads per year in 1970. Efforts imlemented since then have led to a reduction in medically unnecessary X-ray exams.

Special Issues

Limited Knowledge ×Ö´®3

For 70% of the 67,000 chemicals in commerce there is no available information on possible human health effects. A complete health-hazard assessment can be completed for less than 2% of chemicals used commercially, and a partial health-hazard assessment can be completed for 14% of those chemicals. ×Ö´®6

Hazardous Site Clean-Up ×Ö´®1

Out of the 1986 inventory of 23,489 potentially hazardous waste sites, the EPA has listed 541 on the Superfund priority list for cleanup and proposed another 309 sites. As of February 1986, 12 of the priority sites had been completely cleaned up. The cost to clean up a single site averages $8.1 million, and clean-ups take at least 1 year. ×Ö´®1

Effect of Low-Dose Radiation

The risk of cancer induction by low-dose radiation cannot be estimated precisely. It is not clear whether dose rates of about 100 mrads per year (average background radiation dose) are in any way detrimental to those exposed. ×Ö´®4

Depending on the projection model used, it is estimated that if a population of 1 million was exposed to 10 rads of radiation in a single exposure, then there would be 766 to 2,255 deaths from cancer in excess of the 163,800 expected cancer deaths from all causes for that population. The radiation would cause a 0.47% to 1.4% increase in cancer deaths according to these projections.

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