"Precision Castparts, DuPont, Biomet, the Bayer Group and Dow Chemicals are the top five corporate air polluters in the US, say researchers at the Political Economy Research Institute (PERI) at the University of Massachusetts Amherst.
ExxonMobil ranks No. 6, with BASF, LyondellBasell Industries, Renco Group and General Electric rounding out the top 10 in the fifth edition of the Toxic 100 Air Polluters.
The list assess how many pounds of pollutants big firms release as well as the toxicity of chemicals, transport factors such as prevailing winds and height of smokestacks, and the number of people exposed. For example, the No. 1 firm, Precision Castparts, has a toxic score — pounds released multiplied by toxicity multiplied by population exposure) of 16.6 million and releases .11 millions of pounds of toxic pollutants (see chart). No. 2 DuPont, meanwhile, has a toxic score of 7.1 million with 10.94 millions of pounds of toxic air releases, according to the index.
The Toxic 100 Air Polluters index is based on air releases of hundreds of chemicals from 10s of thousands of industrial facilities across the US."