Environmental Defense Fund Adopts Risks Based Approach To Environmental Hazards
August 1, 1998
Environmental advocacy groups have resisted the use of risk analysis for moral, technical or tactical reasons, says John D. Graham of Harvard University. An exception is the Environmental Defense Fund (EDF), "which has an aggressive, forward-looking approach to the use of risk analysis in favor of environmental protection."
Risk analysis attempts to quantify and rank hazards to human health or ecosystems and the cost effectiveness of measures to reduce those risks. One application of risk analysis is determining the hazard posed by exposure to various chemicals -- which requires data on toxicity derived from testing.
- Chemical toxicity may be expressed by various measures -- such as acute toxicity, repeated dose toxicity, reproductive toxicity and developmental toxicity.
- A 1997 EDF study, Toxic Ignorance, concluded a "basic" toxicity database necessary for even a preliminary risk assessment is lacking for more than 70 percent of chemical compounds it examined.
- Although more than 90 percent of the chemicals sampled had been tested for acute toxicity (usually death), more than 50 percent had not been tested for any form of chronic toxicity.
However, what constitutes basic toxicity tests has not been established; the value of testing for some types of toxicity has not been determined; and the type of toxicity that is relevant depends on the particular substance. For instance, some substances that appear harmless in basic tests may pose significant health risks, while others that show toxic effects in basic tests may pose little or no risk to people. Furthermore, performing such tests may be less cost-effective than taking measures to reduce exposure.
Graham notes the EDF study is prompting reconsideration of the Toxic Substances Control Act of 1976 -- a law intended to stimulate testing of chemicals and protect the public from unreasonable risks arising from exposure.
Source: John D. Graham (director, Harvard Center for Risk Analysis), "Risk-Based Environmental Advocacy," Risk in Perspective, August 1998.
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