Over the past several years, considerable public and private efforts in this country have been directed at reducing the risk of cancer that human exposure to high levels of radon gas poses. These efforts appear to have succeeded in raising public awareness of radon and in increasing testing for radon. For the most part, however, these efforts have been directed toward homeowners and have not addressed the problem of radon in residential rental properties. Yet, in 1989, nearly 34 million homes—over one-third of all housing units in the country—were rental units.

A more substantive precautionary principle of international law is evolving as new treaties articulate new measures of precaution in different contexts. Although there is considerable controversy over how to articulate or define a precautionary "principle" of law, the goal is to ensure that the mere lack of scientific knowledge about risks cannot justify a failure to take appropriate precautions. Where we have sufficient evidence of risk, we often take precautions, despite a lack of certainty about those risks.

A recent headline on the front page of the Wall Street Journal hailed the opening of the nation's first "butterfly bank." The "deposits" in this unusual bank are conservation credits earned by preserving an important area of habitat for the Quino checkerspot butterfly, an endangered species restricted to California. The bank's intended customers are other landowners who hope to develop other sites where the butterfly occurs. In order to do so, they can buy credits from the private entrepreneur who established the butterfly bank.

The Resource Conservation and Recovery Act (RCRA), the Clean Water Act (CWA), and the Clean Air Act (CAA) represent federal regulatory regimes for protecting the environment. Although each statute initially places administrative responsibility in the hands of the U.S. Environmental Protection Agency (EPA), each encourages states, to varying degrees, to take primary responsibility for implementing the statutory regime.

In Environmental Federalism Part 1: The History of Overfiling Under RCRA, the CWA, and the CAA Prior to Harmon, Smithfield, and CLEAN, the history of judicial and administrative decisions relating to overfiling under the Resource Conservation and Recovery Act (RCRA), the Clean Water Act (CWA), and the Clean Air Act (CAA) was analyzed. The history showed that the U.S. Environmental Protection Agency (EPA), with limited exceptions, generally was understood to have overfiling authority under RCRA, the CWA, and the CAA. The limited exceptions focused on two situations.

What is an appropriate regulatory response to the enormous growth of pesticide use in developing countries? The question falls within the broader issue of how developing countries deal with the consequences of their application of technological packages to agricultural production. As developing countries step up efforts to improve agricultural production, there are rising concerns about the social and economic costs of their agricultural development in terms of the negative health and environmental impact that pesticides are or are likely to cause.

In late 1999, the U.S. Occupational Safety and Health Administration (OSHA) proposed an expansive ergonomics standard. Its genesis, however, goes back to 1979, when OSHA hired its first ergonomist. Now, more than 20 years later, OSHA is moving forward with a proposed standard that is both extremely far-reaching and, in many ways, unique among health and safety requirements. The proposal, however, suffers from a number of serious deficiencies, including inherent ambiguities within the regulatory language itself.

Editors' Summary: On June 29, 1998, EPA published its PCB Mega Rule, a comprehensive revision of TSCA regulations that govern the remediation and disposal of PCB-contaminated material. The PCB Mega Rule affords the regulated community the option of remediating such material under self-implementing provisions or developing risk-based site-specific remedial measures that generally require Agency approval.

Editors' Summary: After TSCA was enacted in 1976, some commentators described it as the most powerful of all the environmental laws. Congress intended it to provide for the comprehensive and direct control of commercial chemicals' potential health or environmental effects in a true cradle-to-grave tracking system. Indeed, it was the single law addressing toxic substances that could cover all areas of environmental regulation, supplementing sections of existing toxic substances laws. In the 17 years since its enactment, however, TSCA has not fulfilled these goals or expectations.