Lung cancer risks associated with occupational exposure to pairs of five lung carcinogens

Scientists from the International Agency for Research on Cancer (IARC) and partner institutions have found that whereas occupational co-exposure to some known lung carcinogens increased workers’ risk of developing lung cancer in a way that is generally in line with the combined increased risk of the individual agents, some co-exposures created a synergistic effect that increased the risk by more than this combination. The results were published in the journal Environmental Health Perspectives.

The project partners analysed data from 16 900 lung cancer cases and 20 900 control subjects, collected over 15 years by scientists at IARC, in Canada, and in 13 countries in Europe. The researchers estimated the effect that exposure to two carcinogens would have on lung cancer risk. They did this for each possible pairing from a group of five major occupational lung carcinogens: asbestos, respirable crystalline silica, nickel, chromium(VI), and polycyclic aromatic hydrocarbons (PAHs), while also taking cigarette smoking into account.

A stronger effect than the sum of the individual risks was observed for lung adenocarcinoma for chromium(VI)–silica exposure among men, and for small cell lung cancer for silica and joint exposures with asbestos, PAHs, or chromium(VI) among women.

These results underline the importance of eliminating or reducing exposures to carcinogens in workplaces and in the general environment.

Olsson A, Bouaoun L, Schüz J, Vermeulen R, Behrens T, Ge C, et al.
Lung cancer risks associated with occupational exposure to pairs of five lung carcinogens: results from a pooled analysis of case-control studies (SYNERGY)
Environ Health Perspect, Published online 18 January 2024;
https://doi.org/10.1289/EHP13380

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