According to the Society of Environmental Journalists:
EPA released an update of its National-Scale Air Toxics Assessment on June 24, 2009.
The results indicate that almost every person in the US lives in an area where the cancer risk exceeds 10 in 1 million after a lifetime of exposure to selected air toxics, well in excess of EPA’s general target of 1 in 1 million. For 2 million people, the risk is far worse, exceeding 100 in 1 million. The average risk is 36 in 1 million.
For noncancer respiratory risks, nearly everyone in the country lives in an area where the hazard index was higher than EPA’s target of 1.0, and the index was 10 or higher for more than 22 million people. The news was better for noncancer neurological risks, but about 350,000 people still live in areas exceeding the EPA target hazard index of 1.0.
For all three types of health effects evaluated, there are large risk differences between census tracts, between counties, between states, and between regions.