Diesel Fumes Now Classified as Carcinogenic
In June 2012, the World Health Organisation’s International Agency for Research on Cancer (IARC) upgraded the classification of diesel engine exhaust from “probably carcinogenic to humans” to “carcinogenic to humans.” International experts have determined that there is sufficient evidence of a link between exposure to fumes from diesel engine exhausts and the incidence of lung cancer. Petrol engine exhaust fumes were also reviewed but the classification remains unchanged from “possibly carcinogenic to humans.”
Studies found the risk of lung cancer for highly exposed workers increased by three times that of low exposure workers and very highly exposed workers had nearly 6 times the risk of associated cancer mortality.
Diesel exhaust is a combination of a number of chemicals and particles, however exhaust as a whole can be classed as exposure to particulate matter, diesel exhaust being primarily composed of very small particles. Whilst many people would associate the black smoke from exhausts as the harmful substance, in diesel exhausts, it is actually the invisible nano particles that are created by diesel engines which can be inspired deep into the lungs which present the most risk for lung cancer.
Workplaces where workers are in close proximity diesel fuelled equipment or in enclosed spaces with diesel fuelled equipment present the greatest risk to worker health.
How to reduce the risk:
There are several actions that employers can take to reduce the exposure such as: limiting operation of diesel fuelled vehicles in enclosed spaces, using extraction systems or other methods of increasing ventilation to indoor or enclosed areas, using low emission engines and fuels.
Whilst there is no Australian exposure standard for diesel exhaust fumes or an indication from IARC on what levels may be safe, it is recommended that exposure to fumes be limited as much as possible. The Australian National Pollutant Inventory has set occupational exposure limits for diesel exhaust (prior to the new carcinogen classification). These limits are 10 mg per m3 of air averaged over an 8 hour shift, and public exposure limits at 8 µg/m3/yr. Workplace exposures should be minimised to reflect that workers are still members of the public and their average yearly exposure should also not exceed these levels. There are also exposure limits for individual exhaust components such as carbon monoxide, benzene, and sulphur dioxide however the IARC has not indicated which chemicals specifically contribute to cancer risk.