A landmark government health study released last week provides evidence that the diesel engine exhaust that pervades California highways could be causing cancer at a greater rate than previously known.

The study says miners exposed to diesel engine exhaust are three times more likely to contract lung cancer and die, and that a similar increased risk applies to people from smoggy, urban areas such as Southern California who live near freeways or commute to work.

The long-term study, carried out by the National Cancer Institute and the National Institute for Occupational Safety and Health, is described by scientists and advocacy groups as the most thorough study on the topic ever released. The study was published in the current edition of the Journal of the National Cancer Institute.

The data will be examined by the International Agency for Research on Cancer, part of the World Health Organization, at the agency’s meeting in June to decide if diesel exhaust should be re-classified as a known carcinogen. Now, exhaust from diesel trucks, buses, portable generators and off-road construction equipment is classified as a “probable carcinogen.”

In California, studies of exposure to diesel exhaust along freeway corridors and inside cars on truck-congested freeways led the California Air Resources Board in 1998 to classify diesel particulate matter as a toxic air contaminant.

The latest ground-breaking study could lead to even tighter regulations on buses, trucks, locomotives, ships and other sources of black soot emitted into the air and breathed by 16 million Southern Californians.

continue reading New study says diesel emissions can increase risk of cancer three-fold – San Bernardino County Sun.