Association of 13 Occupational Carcinogens in Patients With Cancer, Individually and Collectively, 1990-2017

Importance

Occupational exposure to carcinogens has been shown to pose a serious disease burden at the global, regional, and national levels. Based on epidemiologic studies and clinical observations, working environment appears to have important effects on the occurrence of human malignant tumors; however, to date, no systematic articles have been published that specifically investigated cancer burden due to occupational exposure in an individual and collective manner.

Objective

To estimate the degree of exposure and evaluate the cancer burden attributable to occupational carcinogens (OCs) individually and collectively by sex, age, year, and location.

Design, Setting, and Participants

Cross-sectional study including data on 195 countries from the Global Burden of Diseases, Injuries, and Risk Factors Study from January 1, 1990, to December 31, 2017. Data were analyzed from June 24, 2020, to July 20, 2020.

Exposures

Thirteen OCs (ie, arsenic, asbestos, benzene, beryllium, cadmium, chromium, diesel engine exhaust, formaldehyde, nickel, polycyclic aromatic hydrocarbons, silica, sulfuric acid, and trichloroethylene).

Main Outcomes and Measures

The degree and change patterns of exposure as well as the attributable cancer burden, including deaths and disability-adjusted life years (DALYs), by sex, age, year, and location for 13 OCs. The calculation of the population-attributable fraction was based on past exposure in the population and relative risks.

Results

Based on the GBD 2017 study, 13 OCs attributable to 7 cancer types were included. Most summary exposure values for the 13 OCs, particularly those of diesel engine exhaust (35.6% increase; 95% uncertainty interval [UI], 32.4%-38.5%) and trichloroethylene (30.3% increase; 95% UI, 27.3%-33.5%), increased from 1990 to 2017. Only exposure to asbestos decreased by 13.8% (95% UI, −26.7% to 2.2%). In 2017, 319 000 (95% UI, 256 000-382 000) cancer deaths and 6.42 million (95% UI, 5.15 million to 7.76 million) DALYs were associated with OCs combined, accounting for 61.0% (95% UI, 59.6%-62.4%) of the total cancer deaths and 48.3% (46.3% to 50.2%) of the DALYs. Among the 13 OCs, the 3 leading risk factors for cancer burden were asbestos (71.8%), silica (15.4%), and diesel engine exhaust (5.6%). For most OCs, the attributed cancer outcome was tracheal, bronchial, and lung cancer, which accounted for 89.0% of attributable cancer deaths. China (61 644 cancer deaths), the US (42 848), and Japan (20 748) accounted for the largest number of attributable cancer deaths in 2017; for DALYs, China (1.47 million), the US (0.71 million), and India (0.37 million) were the 3 leading countries.

Conclusions and Relevance

Results of this study suggest that although OC exposure levels have decreased, the overall cancer burden is continuously increasing.