Formal risk assessments, required for setting occupational and environmental health standards in the United States, often pose a severe burden on regulatory agencies and in many cases have caused delays in the development of effective standards. As a result, some environmentalists have questioned the utility of risk assessments for addressing current public health problems. Their concern is that the requirement for risk assessments has become a mathematical straitjacket for regulatory agencies who increasingly appear to be in a state of "paralysis by analysis." What makes the risk assessment process so difficult for regulatory agencies? The problem is that all stages of the risk assessment process (hazard identification, dose-response analysis, exposure assessment, and risk characterization) are fraught with uncertainty, which frequently leads to acrimonious debates among scientists and others about whether there is a risk and about how best to quantify it. Performing risk assessments for occupational and environmental exposures to diesel exhaust is a current example of the problems facing regulatory agencies. The data available for assessing the risk of diesel exhaust exposure are extensive, including publications from over 40 epidemiological studies and numerous chronic animal bioassays and in vitro toxicological studies. Despite this extensive database, there remain substantial challenges in using these data for characterizing human risks, making it difficult for regulatory agencies to complete their risk assessments and to fully develop regulatory policies for diesel exhaust.
Risk-analysis; Risk-factors; Diesel-exhausts; Exhaust-gases; Public-health; Environmental-exposure; Environmental-hazards; Environmental-pollution; Cancer; Cancer-rates; Carcinogens; Lung-disease; Lung-disorders; Lung-cancer; Lung-irritants; Respiratory-system-disorders; Respiratory-irritants; Pulmonary-system-disorders; Exposure-assessment; Epidemiology