The Failures of Risk Assessment
There are many reasons for these failures. But a big part of the problem lies with the standard approach to risk assessment that has come to provide much of the foundation for our approach to understanding and regulating toxic chemicals, pollution, and hazardous waste. There is a long history here that I have investigated in a series of articles (see here, here, and here), which show how formal approaches to risk came to dominate environmental decision-making starting in the early 1980s and, in the process, displaced earlier, simpler approaches founded upon precaution, endangerment, and a healthy respect for uncertainty.
Although risk assessment has often been understood as a largely technical, scientific exercise that provides the basic facts needed for the more value-laden exercise of risk management (itself cast as an exercise in cost-benefit analysis), the history of risk assessment makes clear that it has operated first and foremost as a political technology intended to discipline agencies and constrain their ability to solve complex problems, rather than as a tool to generate useful information about the world. From the beginning, risk assessment was pushed by industry as a way of ensuring that no regulation would proceed until we determined exactly how many workers or how many people might suffer a particular harm from a certain level of exposure. Through the advocacy of organizations such as the American Council on Industrial Health, the Chemical Manufacturers Association, and the American Petroleum Institute, industry-funded scientists and lawyers commandeered the apparatus of fact-making that provides much of the basic infrastructure for regulatory science. This was a far more expansive and successful effort than simply working to manufacture doubt and uncertainty by questioning specific studies and funding alternative research. Indeed, much of the industry perspective was embraced and promoted by the science policy establishment, EPA, and the Supreme Court—all as part of a purportedly more rational and responsible approach to reforming regulation that moved into high gear during the 1980s.
But any honest evaluation of the practice of risk assessment over the past forty years would reveal an approach that has been unable to deliver on even the most basic metrics, as evidenced by reviews from the National Academy of Sciences (which was one of the original proponents of risk assessment) and the Government Accountability Office, among many others. Major individual risk assessment exercises have taken decades to complete, with many thousands of additional chemicals waiting in the queue. The dioxin cancer risk reassessment, for example, has been ongoing for more than thirty years, producing cancer risk estimates that vary by three orders of magnitude with no agreed criteria for how to achieve closure. Similar risk assessments for trichloroethylene and formaldehyde have also taken decades, with substantial variation in risk estimates depending on the models used. And these are some of the most data-rich and well-studied chemicals out there.