The Long, Slow Path to Improved Air Quality Standards

The regulatory process can be slow and tortuous. Consider the case of air quality standards. Since 1997, EPA has had separate air quality standards for fine particulates, technically called PM2.5.  These tiny particles can penetrate deep into the lungs, making them a special public health concern.  EPA has revisited the standard twice, in 2006 and …


Air Pollution Levels in China

The Economist commissioned a study of particulate pollution in China, using estimates based on satellite data.  The results are predictably grim: World Health Organisation guidelines suggest that PM2.5 levels above ten micrograms per cubic metre are unsafe. The boffins have found (as the map shows) that almost every Chinese province has levels above that. Indeed, …