The International Agency for Research on Cancer (IARC), the WHO agency that researches cancer risk, reclassified diesel exhaust fumes from group 2A (probable carcinogens) to group 1 (substances with a definite link to cancer).

‘€œThe (IARC) working group found that diesel exhaust is a cause of lung cancer and also noted a positive association with an increased risk of bladder cancer,’€ the IARC said in a statement.

Diesel fumes contain thousands of particles, including some harmful chemicals that could cause inflammation in the lungs, and over time could lead to cancer.

Since so many people are exposed to diesel fumes – including pedestrians, ship passengers and crew, railroad workers, truck drivers, mechanics, miners and people operating heavy machinery ‘€“ there could be many cases of lung cancer connected to the contaminant, according to the IARC’€™s Kurt Straif.

Given the additional health impacts from diesel particulates, exposure to this mixture of chemicals should be reduced worldwide, the IARC suggested in a statement.

‘€œThis emphasis is needed globally, including among the more vulnerable populations in developing countries where new technology and protective measures may otherwise take years to be adopted,’€ said IARC director Christopher Wild.

The new classification is the result of a week-long discussion between an expert working group in Lyon, France.   They analysed published studies, evidence from animals and limited research in humans.

One of the biggest studies was published in March by the US National Cancer Institute, and analysed 12 300 miners for several decades starting in 1947. Researchers found miners heavily exposed to diesel exhaust had a higher risk of dying from lung cancer.

But lobbyists for the diesel industry argued the study wasn’t credible because researchers didn’t have exact data on how much exposure miners got in the early years of the study; they simply asked them to remember what their exposure was like. A person’s risk for cancer depends on many variables, from genetic makeup to the amount and length of time of exposure to dangerous substances.

A US group that represents diesel engine makers says major technological advances in the last decade have cut emissions from trucks and buses by more than 95% for nitrogen oxides, particulate and sulfur emissions.

This new classification is expected to have economic ramifications for diesel car and truck manufacturers.

Sources: Sapa, AP, Reuters Health