Authored by

Jenny Panzo

Introduction to Environmental Health

Never does nature say one thing and wisdom another.

Juvenal (c.55-127 A.D.)

Outline

Introduction

Policy

Legislation

Clean Air

Water Quality

Food and Drug Safety

Sanitation

Occupational Safety and Health

Environmental Health: International Perspective

Conclusion

Introduction

Prevalent topics in environmental health include air and water quality, waste management, food and drug safety, population growth, occupational health, toxicology, risk assessment, genetics in risk assessment, environmental law, standards, monitoring, and disaster response. From 3000 deaths within hours due to acute exposure to Methyl isocyanate in Bhopal, India, to an outbreak of Cryptosporidium in the Milwaukee water supply, to windblown dust from a dried up lake, Owens Lake, out west as a source of the worst particulate air pollution in the United States; the consideration of environment in health is not a topic to be viewed insouciantly. Following is a window into a topic whose scope is fit for a book unto itself.

Policy

Most standards familiar today in the United States were set in legislation or reassessed in the 1960s and 1970s. Prior to this, public health officials’ primary concerns were sanitation and clean drinking water. In 1857, doctors on the east coast met to discuss concerns regarding sanitation and to create state and local boards of health.[1] The National Quarantine Act of 1878 marked federal involvement in safe drinking water issues.[2] Today the responsibility for setting national standards is a function of government, as well as the states. The states are required to implement and enforce these standards at levels as stringent as those set by government, if not more so. However, there is often a gray area between requirement and enforcement. The pressure to enforce the regulations set by the government often falls upon the States. Enforcement at the federal level usually occurs in a manner that is least restrictive to industry, which is not always in the best interest of the environment or its people. Local regulations also exist at a community level in the form of special service districts.[3]

Often the protection of the public’s health is at odds with the aims of an innovative industrial/economic complex. Standard setting and monitoring is an expensive and controversial enterprise. The main detriment for public health advocates is the lack of a precautionary principle.[4] Substances are often put on the market and assumed safe until proven otherwise, rather than withheld until proven safe. As Rachel Carson noted, focus is often placed only on the blatantly obvious and grotesque immediate effects of an exposure rather than on the exposures with insidious effects at low doses that the population pervasively encounters.[5] Regulation is a slow process by nature due to the sheer amount of chemicals manufactured. An estimated 1,000-1,600 new chemicals are introduced in the U.S. each year.[6] In 1984, information on toxicity was reported as available on only a very small proportion, around 20%, of all known chemicals.[7] Risk assessment and environmental epidemiology studies are often inconclusive due to the difficulties of assessing the nature of an exposure, as well as extrapolating from high dose to low dose exposures. Identifying hazards is a daunting task and the cost in terms of health is often difficult to extricate from the practicality of what is economically feasible. Standard setting decisions are often “value judgements” of a “socio-political nature.”[8] Thus, compounded by the fact that even federal regulatory agencies lack standardized methods.[9] The common undercurrent that has a tendency to lead to underestimation of risk in environmental health: uncertainty.

Legislation

The National Environmental Policy Act (1969)

The National Environmental Policy Act (NEPA) declared the consideration of environment an item requiring national policy. Under NEPA federal agencies that have/will have an impact on the environment are required to submit documentation, environmental impact statements (EIS) and environmental assessments (EA), on proposed actions and consequences thereof. This provides government with the information necessary to respond to such proposals.[10]

Toxic Substances Control Act (1976)

Under the Toxic Substances Control Act new chemicals are required to be registered with the EPA prior to marketing. Imported and exported chemicals must also be reported to the EPA. However, the act stipulates that fulfilling the aims of the TSCA must not unnecessarily impede economic and technological innovation.[11]

Federal Insecticide, Fungicide, and Rodenticide Act (1947)

(Amendments1972,1975,1978,1980,1988)

The Federal Insecticide, Fungicide, and Rodenticide Act requires registration of pesticides with the EPA prior to marketing. The EPA sets tolerance levels for residue on food. States are responsible for enforcing the law under violations.[12]

The Comprehensive Environmental Response, Compensation, and Liability Act (1980)

CERCLA (the Superfund law) focuses attention on the cleanup of hazardous sites. All owners present and past are liable for the cost of cleanup. Under the Superfund Congress provides funds for sites identified and ranked in order of priority by the EPA. The number of sites is estimated to be in the thousands.[13]

Resource Conservation and Recovery Act (1984)

RCRA is the “cradle to grave” policy for regulating hazardous waste. RCRA covers transport, generators, disposal, storage, and treatment facilities. Implementation is carried out by the states.[14]

Emergency Planning and Community Right-to-Know Act (1986)

This act encompasses emergency planning, toxic substances registry, and toxic release inventory programs. The act calls for state planning and public reporting.[15]

Pollution Prevention Act (1990)

The Pollution Prevention Act is the national policy to reduce and prevent source pollution. Other aims include recycling and safe treatment of waste, and disposal into the environment only as a last resort. This act reduced hazardous substances used in industry and has significantly decreased work related exposures.[16]

Occupational Safety and Health Act (1970)

The Occupational Safety and Health Act aims to provide “healthful” working conditions for men and women alike. This act created the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH). The aim of NIOSH is research and OSHA is responsible for the review of NIOSH research as well as proposing new standards and changes to existing standards.[17]

Other

Legislation neither aforementioned, nor covered later in this chapter, includes the Endangered Species Act (1973), Deepwater Port Act (1974), Energy Supply and Environmental Coordination Act (1974), Energy Conservation Act (1976), Nuclear Waste Policy Act (1982), Low Level Radioactive Waste Policy Amendments Act (1985), and the Energy Policy Act (1992), amongst many others.

Clean Air

Clean Air Act (1955, Amendments 1967, 1970 1977,1990)

The Clean Air Act is responsible for setting National Ambient Air Quality Standards (NAAQS). New sources of release are required to conform to the best available control technology (BACT). 1970 Amendment called for a ninety percent reduction in automobile emissions.[18] 1990 Amendment allows pollution allowances to be bought and sold.[19]

There are six EPA identified and monitored criteria air pollutants: particulates, carbon monoxide, ozone, sulfur dioxide, nitrogen oxides, and lead. All are products of combustion. The World Health Organization (1987) has adopted guidelines for these same pollutants.[20] However, air pollution in cities such as Beijing and New Delhi often exceed WHO guidelines five to ten-fold.[21]

Current air quality legislation primarily addresses outdoor ambient pollutants. Relatively little has been done to address indoor air quality. The issue becomes increasingly pertinent as lifestyle changes indicate that people now spend around ninety percent of their time indoors.[22] Common indoor pollutants include radon, environmental tobacco smoke, molds, dust mites, and combustion products from gas stoves and other sources.

The EPA also regulates a variety of other chemical and carcinogenic emissions. It is the responsibility of the EPA to set emission standards for an ever increasing number of chemicals identified by Congress, but relatively few have been acted upon directly. Mercury, benzene, vinyl chloride, and arsenic are among the few that have been.[23] The Clean Air Act largely addresses chemical emission sources, but does little to address individual constituents of pollution. Source categories include steel mills, oil refineries, chemical plants, as well as 45 others, as of 1998.[24]

Epidemiologic studies on air pollution effects are extremely difficult to perform. They are costly and associations are often weak and difficult to detect.[25] Misclassification of exposure is frequent. It is extremely difficult to determine which agents may be responsible for health effects when in a mixture, which is often the case. Historically reconstructing individual exposure presents one of the greatest difficulties. This makes standard setting extremely difficult and controversial.

Several technologies have aided the control of air pollution, such as catalytic converters, the ban on leaded gasoline, and scrubbers on smokestacks.[26]

In addition the Montreal Protocol (1987) has been signed by more than 160 nations to diminish production and use of chlorofluorocarbons (CFCs) to address issues of ozone depletion.[27] A detriment to innovative policymaking has been the United States’ refusal to sign the Kyoto Protocol. The Kyoto Protocol has long been steadfastly opposed by the Business Roundtable, a powerful and influential business association, as an economic hindrance based upon unsound evidence concerning topics such as global warming.[28] Innovative technologies continue to be developed, yet remain costly and difficult to implement and disseminate.

Water Quality

Clean Water Act (1977, Amendment 1987)

The Clean Water Act addresses the state of the nation’s surface waters. Technology based standards dominate regulation. The National Pollution Discharge Elimination System (NPDES) regulates discharge of pollutants and provides necessary enforcement to comply. Permits are issued to point sources to provide emission limits. The 1987 Amendment put forth monitoring and control of wastewater and runoff.[29]

Safe Drinking Water Act (1974 Amendment 1977, 1986, 1996)

The Safe Drinking Water Act regulates underground water quality. The EPA establishes maximum contaminant level goals (MCLGs) for each contaminant. However, while MCLs (Maximum Contaminant Levels) are enforceable, MCLGs are not enforceable. Adoption lies with the states.

Surface water and potable water regulations fall under separate jurisdiction. Agricultural runoff provides the largest contribution to water pollution in the U.S.[30] Air pollution is another major contributor to water pollution.

The Clean Water Act is a series of laws that commenced under the Rivers and Harbors Act in 1899 and progressed into Public Law 92-500.[31] The Clean Water Act is comprised of five Titles, outlining activities such as waste treatment, funding for sewage plants, and standards for reviewing and enforcing water quality. Alternative solutions for keeping the finite source of water on the planet clean include planting vegetation, preventing soil erosion, and reducing pesticide use, among many others.[32]

Pesticides such as the chlorinated hydrocarbons (DDT, PBB) and the alkyl/organophosphates (parathion, malathion), since being introduced, have become pervasive throughout the entire food chain. Waters under the Safe Drinking Water Act are inspected irregularly and often states are unable to monitor the 83 identified contaminants (such as benzene, heptachlor, and vinyl chloride). Most treatment facilities do not treat for pesticides, lead, and other heavy metals in water.[33] There has also been concern over the byproducts of disinfectants, such as chlorine, which may provide additional contaminants. Inspection methods that are outdated continue to be used, such as measures of turbidity[34]. In general most treatment methods are directed towards bacteria and tend to be ineffective against viruses, parasites, and chemical contaminants. In recent years community systems have been required to provide annual reports. In addition to compliance issues such as those in New York City concerning drinking water, outdated and inadequate treatment methods, and irregular monitoring, there is a finite source of fresh water.

Food and Drug Safety

The Food and Drug Administration (FDA) oversees the regulation of food, drugs, and cosmetics, primarily. The United States Department of Agriculture (USDA) oversees meat and poultry inspection while the FDA oversees most other food including fish and seafood but wields little real power to act.[35] The prevalence of food contaminants has shifted over the years from infectious agents to metals and chemicals.[36] Agents include mercury, cadmium, and food additives, amongst a variety of other components. Outbreaks due to chemical agents include toxic oil syndrome in Madrid, Itai-Itai disease and cadmium poisoning in Japan, and methylmercury poisoning in Minimata, Japan. Bacterial and microbial contamination is still the most common cause of food-borne illness. E. coli 0157:H7 and salmonella are the most common.[37]

Some chemicals, including the chlorinated hydrocarbons (DDT, PCB, PBB), which are extremely toxic in acute doses, since being introduced have come to reside in almost every source imaginable. In Silent Spring Rachel Carson reports that prior to the introduction of DDT (dichlorodiphenyltrichloroethane) no chemical like it was found in the body, but post-introduction it is found in almost all body fat sampled and one would be hard pressed to find places in the environment throughout the world where it does not now reside.[38] DDT is understood to be a potent pesticide which is insoluble in fat tissue where it is stored and distributed throughout the food chain.

During the Clinton administration the HAACP (Hazard Analysis Critical Control Point) was adopted. HAACP defines a science-based preventative approach to food safety.[39] However, the FDA and USDA use outdated methods of inspection and only a small amount of all food is tested. The FDA is not required to review new foods and cannot recall products.[40] Its powers are limited and its control over drug regulation has been excessively muddled and confounded by politics.

Sanitation

Cleanup of wastes generated by municipalities and hazardous substances is an area of concern as retaining space becomes a rare commodity. Americans generate an estimated 210 million tons of municipal waste per year.[41] Laws have banned incinerators and dumping of waste into bodies of water. Nearly fifty five percent of solid waste is sent to landfills.[42] The Resource Conservation and Recovery Act (RCRA) sets standards for landfills. However, as space runs out, coupled by the fact that most people oppose new landfills in their backyards, more creative solutions will be necessary. Resource recovery, recycling, is one such alternative. In 1996, the U.S. recycled nearly twenty six percent of solid municipal waste.[43]

Hazardous wastes are covered under the RCRA “cradle to grave” policy. All waste of a hazardous nature must be accounted for, and to be in violation of this amendment is a criminal act. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), otherwise known as the Superfund, identifies and prioritize sites requiring cleanup. As of 1994, twenty two percent of the EPA’s budget was allocated to the Superfund.[44] The Superfund is another controversial, expensive, and slow moving endeavor. Nearly a quarter of the funds allocated to the Superfund have paid for legal battles spent defining liable parties.[45] Superfund sites number in the thousands.[46]

Occupational Safety and Health

Most of what we presently know about toxins has come to us from occupational epidemiology studies. However, workplace exposures usually occur at high doses with acute effects. Extrapolation to the general population has been difficult due to the nature of widespread exposure, which occurs at low doses and long term effects are of interest. Workplace exposure has been very useful in identifying and characterizing toxins such as lead, silicate, and polyvinyl chloride. However, industry is a powerful and driving economic force and it has often been difficult to garner evidence and good science when chemicals or practices are called into question. Many epidemiologic studies have been funded by industry itself. This has introduced a great deal of bias into the process and the outcome of studies.

The National Institute for Occupational Safety and Health (NIOSH) is the primary data collection body that supplies research information on worker safety and health to the Occupational Safety and Health Administration (OSHA). OSHA develops programs with the states and reviews NIOSH recommendations when making changes in current standards. OSHA is also responsible for workplace inspections. A major limitation of the Occupational Safety and Health Act is the number of inspectors, state and federal, responsible for over 6 million sites: 2000.[47]

Environmental Health: International Perspective

Although the developed world contributes three-fourths of all greenhouse gas emissions, despite being comprised of a mere one-fifth of the world’s population, developing countries have a unique profile concerning pollution and environmental health stressors.[48] Environmental exposures in developing countries tend to differ in nature from those in industrialized nations. Household exposures and limited access to resources are prevalent predicaments. WHO (1993) estimates nearly 50% DALYs are due to diseases associated with environmental exposures in the household and 30% due to diseases within the community.[49] In sub-Saharan Africa, nearly 70% of the population lack sanitation and 50% lack safe drinking water.[50] Nearly 40% of the world’s population lack access to safe drinking water.[51] Infectious disease is often spread due to infringement upon the environment, such as through deforestation, desertification, dam building, and irrigation.[52] Leaded gasoline continues to be sold in Africa and contains a higher lead content than found elsewhere.[53] Blood lead levels remain increasingly high in places such as Cape Province, South Africa and Dhaka, Bangladesh and over 100 countries still employ the use of leaded gasoline despite its adverse affects on cognitive development.[54] Industrialized countries, given access to vast amounts of knowledge, have a responsibility to aid developing countries in endeavors to make environments safer. Instead, hazardous industries are outsourced and the best technological safety measures are not employed.[55]

Conclusion

In the United States efforts will continue to be made where technology leads. Efforts so far have had a tendency towards passive amelioration of aversive situations rather than prevention and ensuring safety. Until efforts are made to shift the focus from remediation to prevention standards will continue to be set and changed in retrospect and not proactively. This does a great disservice to public health.

As certain facts have come to light and communities have begun to become involved a new precedent has been set. Issues such as environmental racism/justice may no longer be ignored. In 1992 the EPA established the Office of Environmental Justice to monitor activities of industry that disproportionately affect minority communities. Community members have started to take action and high profile cases such as those taken on by the Tulane Environmental Law Clinic in Louisiana have shed new light on these issues.

In other parts of the global community different tactics have been employed. In 1996 in Mexico City, one of the most polluted urban areas in the world, cars were categorized and tagged according to emissions levels and pollution control technology. Cars must comply with the “A Day Without a Car” law unless a sticker with a 0 is assigned, allowing the car to be driven every day.[56] In turn, it is hoped that this will prompt people to purchase newer and less polluting cars.

In the future more creative solutions and preventive measures will need to be applied. The paradigm will need to shift to one in which economic advantages do not trump good practices and good health. Any change in the biosphere is a change in our (human) habitat as well. It is in the interest of all to know just what we are “adapting” to. The environment does not have an infinite ability to sustain us and surely even technology is not more powerful nor awesome than what has always been out there and we are just now discovering.

References

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[1] Luneburg, W.V. “The Legal Context of Environmental Protection in the United States.” Talbott and

Craun, Introduction to Environmental Epidemiology. MI: Lewis Publishers, Inc: 1.

[2] Ibid: 2.

[3] Vigil, K.M. (1996). Clean Water: An Introduction to Water Quality and Water Pollution Control.

Corvallis, OR: Oregon State University Press, 2003: 103.

[4] Markowitz,G.,& Rosner, D. (2002). Deceit and Denial: The Deadly Politics of Industrial Pollution. New

York, N.Y.: The Milbank Memorial Fund, 2003: 6.

[5] Carson, R.(1962). Silent Spring. New York, N.Y.: Mariner Books, 2002: 190.

[6] Tilson, H.A., MacPhail, C., & Crofton, K.M. (1996). Setting exposure standards: A decision process.

Environmental Health Perspectives, 104 (Suppl 2), 401-405.

[7] United States. National Research Council. Toxicity Testing: Strategies To Determine

Needs and Priorities. Washington, D.C.: National Academy Press, 1984: 118.

[8] Sterner, J., Chair, Environmental Health Advisory Committee. “Report to the Board of Directors of the

Manufacturing Chemists’ Association, Inc.” MCA Papers, March 14, 1967.

[9] Moeller, D.W. (1992). Environmental Health. Cambridge, MA: Harvard University Press, 2003: 300.

[10] Luneburg, W.V. “The Legal Context of Environmental Protection in the United States.” Talbott and

Craun, Introduction to Environmental Epidemiology. MI: Lewis Publishers, Inc: 14.

[11] Moeller, Environmental Health: 286.

[12] Moeller, Environmental Health: 289.

[13]Moeller, Environmental Health: 288.

[14] Luneberg, The Legal Context of Environmental Protection in the United States: 19.

[15]Moeller, Environmental Health: 284.

[16]Moeller, Environmental Health: 281.

[17] Moeller, Environmental Health: 290.

[18] Schneider, M.J. (2000). Introduction to Public Health. Gaithersburg, MD: Aspen Publishers, Inc., 2000:

316.

[19] Moeller, Environmental Health: 274.

[20] Dockery, D.W., & Pope III, C.A. “Outdoor Air I:Particulates.” Steenland and Savitz, Topics in

Environmental Epidemiology. NY: Oxford University Press, Inc.: 121.

[21]McMichael, A.J., Kjellström, T., & Smith, K.R. “Environmental Health.” Merson, Black, and Mills,

International Public Health. MA: Jones and Bartlett Publishers: 414.

[22] Moeller, Environmental Health: 39.

[23] Schneider, Introduction to Public Health: 316.

[24] Ibid.

[25] Dockery, D.W. (1993). Epidemiologic study design for investigating respiratory health effects of

complex air pollution mixtures. Environmental Health Perspectives, 101 (Suppl 4), 187-191.

[26] Schneider, Introduction to Public Health: 322.

[27] Ibid.

[28] Markowitz,G.,&Rosner, D. (2002). Deceit and Denial: The Deadly Politics of

Industrial Pollution. New York, N.Y.: The Milbank Memorial Fund, 2003: 297.

[29] Schneider, Introduction to Public Health: 278.

[30] Schneider, Introduction to Public Health: 330.

[31] Vigil, Clean Water: An Introduction to Water Quality and Water Pollution Control: 82-83.

[32] Ibid.

[33] Schneider, Introduction to Public Health: 332.

[34] Schneider, Introduction to Public Health: 331.

[35] Schneider, Introduction to Public Health: 361.

[36] Posada de la Paz, M. “Diet and Food Contaminants.” Steenland and Savitz, Topics in

Environmental Epidemiology. NY: Oxford University Press, Inc.: 64.

[37] Ibid: 65.

[38] Carson, Silent Spring: 178.

[39] Schneider, Introduction to Public Health: 353.

[40] Ibid.

[41] Schneider, Introduction to Public Health: 339.

[42] Schneider, Introduction to Public Health: 340.

[43] Franklin Associates. (1997). Characterization of Municipal Solid Waste in the United States:1997

Update. U.S. Environmental Protection Agency Report No. EPA530-R-98-007. KS: Prairie Village,

1998: 2.

[44] Schneider, Introduction to Public Health: 346.

[45] Schneider, Introduction to Public Health: 345.

[46] Moeller, Environmental Health: 288.

[47] Moeller, Environmental Health: 290-291.

[48] Intergovernmental Panel on Climate Change. (1996). Second assessment report: Climate change 1995

(Vols.I –III). New York, N.Y.: Cambridge University Press. McMichael, Kjellström, and Smith: 422.

[49] McMichael, A.J., Kjellström, T., & Smith, K.R., Environmental Health: 381.

[50] McMichael, A.J., Kjellström, T., & Smith, K.R., Environmental Health: 380.

[51] McMichael, A.J., Kjellström, T., & Smith, K.R., Environmental Health: 404.

[52] McMichael, A.J., Kjellström, T., & Smith, K.R., Environmental Health: 434.

[53] McMichael, A.J., Kjellström, T., & Smith, K.R., Environmental Health: 388.

[54] Ibid.

[55] LaDou, J., &Jeyaratnam, J. (1994). Transfer of hazardous industries:Issues and solutions. Occupational

Health in National Development. River Edge, N.J.: World Scientific Publications. McMichael,

Kjellström, and Smith: 412.

[56] McMichael, A.J., Kjellström, T., & Smith, K.R., Environmental Health: 417.

Bibliography

Bower, J. (2000). The Healthy House : How to buy one, How to build one, How to cure a sick one, 4th revised ed. Bloomington, IN: The Healthy House Institute, 2000.

Brower, M. (1999). The Consumer’s Guide to Effective Environmental Choice: Practical Advice from the Union of Concerned Scientists. Three Rivers, MI: Three Rivers Press, 1999.

Bullard, R.D. (2000). Dumping in Dixie: Race, Class, and Environmental Quality. Boulder, CO: Westview Press, Inc., 1990.

Carson, R.(1962). Silent Spring. New York, NY: Mariner Books, 2002.

Schneider, D., & Freeman, N. (2000). Children's Environmental Health: Reducing Risk in a Dangerous World. Washington D.C.: American Public Health Association, 2000.

Godish, T. (2003). Air Quality, 4^th Edition. Boca Raton, FL: CRC Press LLC, 2004.

Godish, T. (2000). Indoor Environmental Quality. Boca Raton, FL: CRC Press LLC, 2000.

Institute of Medicine. (2000). Clearing the Air: Asthma and Indoor Air Exposures. Washington DC: National Academies Press, 2000.

Koeppel, G.T. (2000). Water for Gotham. Princeton, NJ: Princeton University Press, 2001.

Markowitz,G.,& Rosner, D. (2002). Deceit and Denial: The Deadly Politics of Industrial Pollution. New

York, NY: The Milbank Memorial Fund, 2003.

Moeller, D.W. (1992). Environmental Health. Cambridge, MA: Harvard University Press, 2003.

Schneider, M.J. (2000). Introduction to Public Health. Gaithersburg, MD: Aspen Publishers, Inc., 2000.

Vigil, K.M. (1996). Clean Water: An Introduction to Water Quality and Water Pollution Control. Corvallis, OR: Oregon State University Press, 2003.

Websites

Agency for Toxic Substances and Disease Registry www.atsdr.cdc.gov

Center for Health, Environment, and Justice www.chej.org

Children’s Environmental Health Network www.cehn.org

Citizens for a Better Environment www.cbew.org

Earth First www.earthfirst.org

Environmental Health Perspectives ehp.niehs.nih.gov

Environmental Law Institute www.eli.org

Greenpeace International www.greenpeace.org/international

Laws and Regulations www.epa.gov/epahome/laws.htm

National Institute of Environmental Health Sciences www.niehs.nih.gov

National Institute for Occupational Safety and Health www.cdc.gov/niosh/homepage.html

National Lead Information Center www.epa.gov/lead/nlic.htm

National Oceanic and Atmospheric Administration www.noaa.gov

New Ideas in Pollution Regulation www.worldbank.org/nipr/index.htm

Occupational Safety and Health Administration www.osha.gov

Tulane Environmental Law Clinic www.tulane.edu/~telc

United Nations Environment Programme www.unep.org

United States Geological Survey www.usgs.gov

US Environmental Protection Agency www.epa.gov

USEPA Maximum Contaminant Levels www.epa.gov/safewater/mcl/html

USEPA Office of Groundwater and Drinking Water www.epa.gov/ogwdw

USEPA Office of Wastewater www.epa.gov/owmitnet

Working Group on Community Right to Know www.crtk.org