The diesel-cancer link established

Concern about lung cancers caused by diesel exhaust is old. The International Agency for Research on Cancer (IARC) classifies diesel engine exhausts as "probably carcinogenic to humans," the middle classification between known human carcinogens and possible human carcinogens. But a conclusive study done in the US was suppressed by the automobile lobby. It has finally been published.

US government agencies began considering regulation of worker exposure to diesel particulates, especially in the mining industry where operation of diesel machinery in the confined spaces underground results in some of the highest exposures. The existing data was challenged.

So in 1992, the National Cancer Institute began developing a study (the Diesel Exhaust in Miners Study) intended to finally review a large enough population with enough quantitative exposure data. The Diesel Coalition of the Methane Awareness Resource Group (MARG), an organization representing the mining industry, successfully derailed publication of the study data and results for a decade and a half.

Finally in early part of this century, the study resurfaced. The Diesel Exhaust in Miners Study reviewed the cases of 12,315 workers at eight non-metal mining facilities,the largest population ever studied. Researchers looked at the available data from two angles: a Cohort Mortality Study with Emphasis on Lung Cancer, and a Nested Case-Control Study of Lung Cancer and Diesel Exhaust.

It has confirmed the link between working in mines and getting lung cancer, strengthening the suspicion that diesel exhaust could be causing cancer. Cause for city-zens to be alarmed? Yes. With more private vehicles plying on the highly-subsidised diesel, imagine the exposure to exhaust for every city resident.