A new study has estimated the proportion of lung cancers in Canada which occupational diesel engine exhaust fumes are responsible for[i]. The number of workers exposed to diesel engine exhaust fumes, between 1961 and 2001, were estimated using data from the Canadian Census and Labour Force Survey data, while the risks of lung cancer were calculated by pooling results from studies in the literature. The proportions of lung cancer due to occupational diesel fumes were calculated and assessed with respect to 2011 lung cancer statistics.
The analysis led to an estimate that 2.4% of lung cancers in Canada were attributable to occupational diesel engine exhaust exposure. This corresponded to approximately 560 (range 380 to 1570) new cases and 460 (range 310 to 1270) deaths in 2011. Overall, 1.6 million individuals alive in 2011 were occupationally exposed to diesel fumes between 1961 and 2001, 97% of whom were male. The occupations with the highest burden were underground miners, truck drivers and mechanics. Half of the attributable lung cancers were found in workers exposed to low levels of diesel fumes.
In 2012, the proportion of lung cancer deaths in the UK, onset by occupational diesel exhaust exposure, was estimated to be 1.84%. This corresponded to 695 (range 313 to 1269) new cases and 605 (range 272 to 1107) deaths[ii].
The attributable fraction derived from the Canadian study differs slightly from the study conducted in the UK. Differences in the number of diesel-related lung cancers, recorded in Canada and the UK, are down to variation in the number and proportion of workers occupying affected industries and job roles, variation in workplace practice, and variation in exposure prevention methods employed. Moreover, exposure to other lung cancer-causing agents, such as cigarette smoke, may have skewed the percentage of diesel fume-related lung cancer deaths.
The latest Canadian study was the first to quantify the burden of lung cancer attributable to occupational diesel exhaust fumes in the country. The authors concluded that their findings underscore a large potential for prevention and a significant public health risk.
[i] Kim, J. et al. Burden of lung cancer attributable to occupational diesel engine exhaust exposure in Canada. Occup Environ Med oemed-2017-104950 (2018). doi:10.1136/oemed-2017-104950 (Accessed 30 April 2018)