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XII. Exposure and Health Effects

Source: EPA 1994 Toxics Release Inventory
Public Data Release, Appendix A:
Questions and Answers


Q89 What amount of toxic chemicals am I exposed to?

A Estimating exposure based on release quantities requires an analysis of chemical- and site-specific characteristics. There is no simple conversion of release quantity to concentration in the environment or dose received by individuals.

Natural environmental processes can transform the chemical (e.g., sunlight decomposes some chemicals); transfer it from one medium to another (e.g., evaporation may transfer some chemicals from water to air); or concentrate it (e.g., bioaccumulation of the chemical in fish). Concentration in the environment can depend on many factors such as the volume of water in the receiving stream into which the chemical is released, dispersion of air releases as a function of local meteorological conditions, the height from which an air release occurs, integrity of landfill liners or other containment of disposed materials, and many other factors. Finally, your exposure to the chemicals will depend on factors such as distance from the release, and the source and treatment of your drinking water supply, etc.

Q90 What are my chances of getting sick when I have been exposed to chemicals?

A The likelihood of becoming sick from chemicals is determined by the length of time you are exposed, the amount of chemical to which you are exposed and as well as the "inherent" toxicity of the chemical. The risk increases as the amount of exposure increases.

Q91 When are higher exposures more likely?

A Accidents can expose the facility's workers and surrounding community to higher concentrations of the chemicals. Other conditions that increase risk of exposure include dust-releasing operations (grinding, mixing, blasting, dumping, etc.), other physical and mechanical processes (heating, pouring, spraying, and evaporation from large surface areas such as open containers), and "confined space" exposures (working inside vats, reactors, boilers, small rooms, etc.). During process start-up and shutdown operations, there also is a greater likelihood of exposure. The closer one is to a release, the greater the potential for exposure.

Q92 Is the risk of getting sick higher for workers in the facilities than for community residents?

A Yes. Exposures in the community, except possibly in cases of fires or spills, are usually much lower than those found in the workplace. However, people in the community may be exposed to contaminated water and chemicals in the air over long periods. Because of this, and because of exposure of sensitive populations, such as children or people who are already ill, community exposures may cause health problems.

Q93 If I have acute (short-term) health effects, will these actually develop into chronic effects?

A Not always. Most chronic (long-term) effects result from repeated exposures to a chemical. Although many acute effects are reversible, some exposures may also cause chronic health effects.

Q94 Can I get long-term effects without ever having short-term effects?

A Yes, because long-term effects can occur from repeated or continuous exposures to a chemical at levels not high enough to make you immediately sick.

Q95 Do all chemicals cause cancer?

A No. Most chemicals tested by scientists do not cause cancer.

Q96 Should I be concerned if a chemical causes cancer in animals?

A Yes. Most scientists agree that a chemical that causes cancer in animals should be treated as a suspected human carcinogen unless proven otherwise.

Q97 Should I be concerned if a chemical is a teratogen (a substance which causes fetal malformations) in animals?

A Yes. Although some chemicals may affect humans differently than they affect animals, damage to animals suggests that same damage can occur in humans.

Q98 But don't they test animals using much higher levels of a chemical than people usually are exposed to?

A Yes. That's so effects can be seen more clearly using fewer animals. But high doses alone don't cause cancer unless the chemical is a cancer agent. In fact, a chemical that causes cancer in animals at high doses could cause cancer in humans exposed to low doses, especially over long periods of time.

Q99 Can men as well as women be affected by chemicals that cause reproductive system damage?

A Yes. Some chemicals reduce potency or fertility in either men or women. Some damage sperm and eggs, possibly leading to birth defects.

Q100 Aren't pregnant women at the greatest risk from reproductive hazards?

A Not necessarily. Pregnant women are at greatest risk from chemicals which harm the developing fetus. However, chemicals may affect the ability to have children, so both men and women of child-bearing age are at higher risk.

Q101 What is the risk to public health resulting from toxic emissions to the air?

A While the TRI data represent a useful means of identifying potential sources of toxic chemicals in the air, these data are not sufficient to accurately determine the magnitude of the public health risk posed by the emissions from a given facility. For example, TRI provides no information concerning the potential exposure to these emissions. These data are most useful to point out the direction for further analyses of public health risk. In addition to identifying new regulatory projects, the data can be used to make priority decisions for the air toxics regulatory agenda.

Q102 Is there any difference between fugitive and stack air emissions when it comes to my health?

A Dispersion of the chemical and its concentration at various distances from the point of release are affected by whether, for example, the chemical is emitted from a tall stack at high temperatures or a pipe fitting near the ground at ambient temperature. Thus, your exposure could vary depending on the manner in which the release occurs. In general, a ground or nearground release, such as through fugitive emissions, will more likely result in a higher exposure and, therefore, a greater possible health hazard for nearby residents than emissions from tall stacks.

Q103 Can my drinking water be contaminated by these toxic chemicals?

A Again, this depends on the amount and concentration released, among other things. Characteristics at the site-- including the relationship of the release to the water supply; geology and hydrology of the soil, both at the surface and below ground; and the distance to where the drinking water intake/well is located--will be determinants of drinking water contamination. Treatment, if any, that the water receives before it is piped to your house will also affect the quality of the water you drink.

Q104 Are the facilities with the largest toxic chemical releases always the most important in terms of public health?

A No. It is not possible to determine risks to public health strictly from knowing the amount of a chemical which is released by a facility over a year. A release total is an important first step in identifying a facility that may pose a public health hazard. Other factors that are necessary to the risk assessment process include specific information on: the environmental medium of the release, chemical toxicity and potency, local meteorological and topographical characteristics, where people live and work (potential population exposure), and when and how releases occur. Because some chemicals are more toxic than others, knowing only the quantity of chemicals released to the environment is not sufficient to determine its importance with respect to risk.

Q105 Is there a risk of getting sick when I have been exposed to a chemical that is released in small quantity?

A It depends upon the inherent ability of the chemical to cause an effect. Chemicals such as cyanide can make you sick even if you are exposed to a small quantity.

Q106 Why should I be concerned about getting ill when I am exposed to pharmaceuticals and pesticides which have been tested for safety?

A Uncontrolled use of such chemicals may pose the likelihood of an individual becoming sick depending upon how long that person is exposed and the amount of exposure. It will also depend upon the inherent toxicity of the chemical.

Q107 How does EPA determine the health and environmental effects of chemicals?

A EPA has developed guidelines to assess these effects. The available information on each chemical is evaluated using these guidelines and a determination is made on a case-by-case-basis. EPA is currently in the process of revising these guidelines. For further information call the EPCRA Hotline, (800) 535-0202.

Q108 Why should I be concerned about chemicals that accumulate at extremely low levels?

A These chemicals are persistent and accumulate in soil, plants, and organisms and, therefore, pose the chance of causing an adverse impact on human health and the environment even when released at low levels. Over a number of years such chemicals can accumulate into larger and larger quantities.

Source: USEPA 1994 Toxics Release Inventory Public Data Release (EPA 745-R-96-002, June 1996).

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