The World Health Organization (WHO) has reclassified diesel exhaust fumes as carcinogenic to humans. After a week of meetings in Lyon, France, the International Agency for Research on Cancer ( IARC ), which is part of the WHO, announced the change of status of diesel fumes on June 12.

“There has been mounting concern about the cancer-causing potential of diesel exhaust, particularly based on findings in epidemiological studies of workers exposed in various settings,” reads the WHO statement. Mounting scientific evidence led to the reclassification into the highest grouping for substances linked to cancer, specifically lung cancer, and the widespread exposure to diesel fumes in the world's populations makes it of particular concern.

The new classification deems diesel fumes more dangerous than passive smoking. “The scientific evidence was compelling and the Working Group’s conclusion was unanimous: diesel engine exhaust causes lung cancer in humans. Given the additional health impacts from diesel particulates, exposure to this mixture of chemicals should be reduced worldwide,” said Dr Christopher Portier, Chairman of the IARC working Group.

The report highlights the increased risk faced by workers with greater occupational exposure to diesel fumes and that the problem goes beyond exhaust fumes from diesel powered road vehicles, giving ships, trains and generators as further examples. The WHO acknowledges the efforts to reduce fumes in many countries and speculates that modern higher efficiency, lower pollution engines may reduce the risk of cancer, but adds that there is not enough scientific evidence to determine the impact.

Conversely, the report draws attention to areas where populations are exposed to fumes from older, poorly maintained diesel engines as potentially carrying a higher risk of cancer. Diesel fumes were previously classified as 'probably carcinogenic' in 1988. The WHO uses three levels to classify potentially cancer causing substances: 'possibly carcinogenic,' 'probably carcinogenic' and 'carcinogenic.'

Liam Lever, liam@romania-insider.com

(photo source: sxc.hu)