According to new data from the Environmental Protection Agency which has analyzed toxic air pollutants, although the average national cancer risk has declined since the last analysis was conducted, millions of people living across the country are exposed to high levels of toxic air pollutants.

Called the National-Scale Air Toxics Assessment, or NATA, the study analysis is based on emissions from 2002, the latest year for which the EPA had detailed estimates of pollution from across the nation. Based on the study results the EPA identifies the areas of the country where the residents face the greatest health threat from air pollution.

According to the report millions of people living in 600 neighborhoods across the country are breathing high concentrations of toxic air pollutants which put them at a greater risk of contracting cancer with New York, Oregon and California facing the highest risk. Surprisingly apart from major cities facing air pollution there were some counties in rural areas of Mississippi and Kentucky, where air pollution was even worse. Industrial areas tend to have the greatest risk.

The report said almost 2.2 million people lived in these neighborhoods with 847,000 in New York City where the air levels of 80 cancer-causing substances released by automobiles, factories and other sources in these areas exceed a 100 in 1 million cancer risk.

The worst single neighborhood was between two freeways in Cerritos, Calif., outside Los Angeles where, the EPA estimated an excess cancer risk of more than 1,200 in 1 million, which was 34 times the national average.

In 2006, data covered 1999 emissions and the average cancer risk was 41.5 in 1 million which was higher than the current average of 36 in 1 million which covers pollution released in 2002.

John Walke, clean air director for the Natural Resources Defense Council said, the assessment "shows we have a problem we should expect government to solve by reducing toxic air pollution, because it makes a lot of people sick."