Old Dry-cleaners: Better Regulation Would Not Require More Science

We spend some 90 percent of our time indoors. There we risk exposure to a panoply of pollutants, including lead, radon gas, asbestos, mold—and perchloroethylene from former commercial dry-cleaners. PCE contamination travels in groundwater, where it vaporizes. It is a well-known hazard facing those living near old dry-cleaners.

The regulation of indoor pollutants is a knotted octopus. Some of its tendrils reach federal, state, and municipal pollutant statutes and regulations. Other arms touch state and municipal regulation of property sale and ownership, of rental housing, and of businesses such as restaurants, day-care centers, and construction companies. Yet other appendages entail public education and voluntary actions.

A little chunk of that regulatory scheme is ASTM International’s new standard E1527-21, for conducting Phase 1 environmental site assessments, finalized last fall. EPA participated in developing the standard, and is currently reviewing it. The agency will almost certainly approve the new standard later this year; it will then replace the 2013 standard in regulations under the Comprehensive Environmental Response, Compensation, and Liability Act—the Superfund law.

Commercial and industrial property purchasers typically order Phase 1 assessments for the narrow purpose of avoiding or mitigating liability under CERCLA, and more broadly to identify other environmental hazards. The previously prevalent dry-cleaning solvent PCE, and its various chemical breakdown products, are directly covered under the Superfund statute. Yet Phase 1 assessments not infrequently also address “non-scope” toxics, such as asbestos, radon, lead, and mold. Indeed, the new ASTM standard specifically addresses PFAS, a widespread, persistent hazard found in non-stick kitchen cooking pans and many other consumer and industrial products. It is not currently regulated under Superfund, but is the subject of ongoing regulatory action.

What I find especially striking here is the contrast between our advanced scientific understanding of these pollutants, versus how little we know about their effective and economical regulation. There is an immense body of science on the human health risks from CERCLA toxics, and from prominent non-scope indoor pollutants. That science is compelling, and by and large settled. Moreover, there is often no known safe level of exposure, as for lead and radon. Though I suspect many scientists would disagree, my view is we know so much already that there is little marginal benefit to public health of further scientific study.

Yet we know hardly anything about how to design effective and economically efficient rules for exposure reductions. We do not design regulatory programs analogous to how we design bridges and airplanes. We just muddle through, doing what is possible—and hopefully sensible—given existing political, institutional, and economic constraints.

There is an incipient technical literature on design of regulatory programs. See for example Eric Seymour and Joshua Aker’s papers on lead poisoning in children in Detroit. They recommend regulatory interventions specifically at the points of tax foreclosure sales, ownership of rental properties, and building demolition.

The methodologies used to assess regulatory effectiveness are inherently weak. By necessity, they are retrospective observational studies. Controlled experiments are essentially impossible. Often, the strongest part of the study is not quantitative data, but a verbal narrative. Even worse, the rulemaking schemes being studied are shifting due to ongoing regulatory action. We humans willy-nilly change the system itself (the very point of regulation), even as we attempt to study it.

For PCE, lead, and other toxics, a key point of regulatory intervention is property sale. Though effective, regulation of property transfers has drawbacks. Superfund’s liability provisions cause some owners of contaminated property to simply decide not to sell, thereby avoiding a transfer. That limits, or at least delays, their liability, yet has no beneficial impact whatsoever on the community. We need better regulation at points other than property sale. As one example, CERCLA safe harbor regulations to encourage soil vapor extraction systems could considerably mitigate many PCE human health dangers.

The new ASTM standard, like Phase 1 environmental assessments, is a complicated technical document. We need both high quality and detailed standards like E-1527-21, and especially additional research on design of more effective regulatory programs. Not infrequently, further scientific research on toxics will be of minimal value to public health.