Time to harmonize national ambient air quality standards

The World Health Organization has developed ambient air quality guidelines at levels considered to be safe or of acceptable risk for human health. These guidelines are meant to support governments in defining national standards. It is unclear how they are followed.; We compiled an inventory of ambient air quality standards for 194 countries worldwide for six air pollutants: PM2.5, PM10, ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide. We conducted literature and internet searches and asked country representatives about national ambient air quality standards.; We found information on 170 countries including 57 countries that did not set any air quality standards. Levels varied greatly by country and by pollutant. Ambient air quality standards for PM2.5, PM10 and SO2 poorly complied with WHO guideline values. The agreement was higher for CO, SO2 (10-min averaging time) and NO2.; Regulatory differences mirror the differences in air quality and the related burden of disease around the globe. Governments worldwide should adopt science based air quality standards and clean air management plans to continuously improve air quality locally, nationally, and globally

Principled Standard Setting Requires Consideration of More Than Science (AEI-Brookings Joint Center for Regulatory Studies, Brief 00-02) Brief Amicus Curiae in Support of Respondents, Browner v. American Trucking Associations, Inc., No. 99-1257, (U.S. September 11, 2000)(with 20 Law Professors, Economists, and Scientists)

Summary of Argument: Throughout this proceeding, EPA has identified no policy or normative criteria to justify its NAAQS standards, thus suggesting that science alone can be used to determine the appropriate air quality standard. Science plays a critical, indeed essential, role in evaluating the risks of possible air quality standards being considered for adoption by EPA. However, science by itself cannot provide the justification for selecting a particular air quality standard. Especially in setting standards for non-threshold pollutants, such as in this case, scientific evidence cannot alone indicate where the standard should be set, since any level above zero will cause some health effects. To provide a principled and consistent basis for justifying the setting of such standards at some level above zero, EPA must articulate other factors -- whether they be costs or other policy criteria -- to guide its decisions on where to set national ambient air quality standards

The Search for an Intelligible Principle: Setting Air Quality Standards under the Clean Air Act

Heather L. Ross weighs in on the controversy surrounding the EPA's setting of National Ambient Air Quality Standards. She forcefully argues that balancing costs and benefits is the only intelligible principle that comports with common sense.

Black carbon as an additional indicator of the adverse health effects of airborne particles compared with PM10 and PM2.5.

Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM(10)) or ≤ 2.5 μm (PM(2.5))] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration

Crossroads for Federal Enforcement of the Clean Air Act

A major goal of the Clean Air Act 1 (hereinafter CAA or Act ) is to protect and enhance the quality of the Nation\u27s air resources. 2 The Act uses a two tiered approach to accomplish this goal. First, the Act focuses on the national attainment and maintenance of National Ambient Air Quality Standards (NAAQS) for criteria pollutants, 3 and second, the Act also sets specific standards for known hazardous air pollutants (HAPS) 4 . The Act emphasizes throughout its text that air quality problems are national in scope and often cross state boundaries. 5 Congress clearly intended that enforcement of programs to improve air quality be a cooperative effort of state and federal governments. 6 Courts also have recognized for decades the necessity of a federal enforcement presence in the effort to improve air quality nationally. As the D.C. Circuit Court noted, EPA ... is the ultimate supervisor, responsible for approving state plans and for stepping in, should a state fail to develop or to enforce an acceptable plan... EPA is to ensure national uniformity where needed, for example, to ensure that states do not compete unfairly for industry by offering air quality standards that are too lax to bring about needed improvement in the air we breathe. 7 An important component of many federal environmental laws is federal enforceability. The federal enforceability 8 of state air quality limitations or controls on sources requires that the Administrator of the EPA, not solely state or local authorities, enforce emission ..