Air Pollution

Pursuant to a congressional request, GAO reviewed the Environmental Protection Agency's (EPA) decision to regulate benzene emissions through controls on automobile refuelling.

GAO noted that: (1) EPA based its decision to control benzene emissions on risk assessments that evaluated the relationship between benzene exposure and the potential occurrence of leukemia; (2) the health, emission, population, and modeling data EPA used were based on assumptions; (3) EPA did not consider three relevant health studies completed between 1981 and 1983 because it believed that the studies would not significantly change its benzene health assessment; (4) EPA emission data showed that three plants were using benzene to manufacture a product used in making plastics and chemicals, but only one plant was actually using benzene at the time EPA issued its final decision; and (5) EPA updated some information that changed its estimate of risk to the public, but was not significant enough to change its 1983 decision. GAO found that: (1) as of October 1985, EPA did not have written guidance detailing how quantitative risk assessment values are developed for hazardous air pollutants; (2) EPA plans to control automobile refuelling emissions will be based on a decision as to whether nationwide or local controls should be implemented; (3) California and the District of Columbia have implemented controls on gasoline pumps in the absence of EPA regulations for controlling refuelling vapor; (4) if the risk from gasoline vapor and/or benzene is not significant, EPA could require controls only in those areas not in compliance with EPA ozone standards; and (5) more than 2 years will be required for implementing the automobile refuelling control options.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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