BACKGROUND: Prior studies have indicated associations between ingestion of inorganic arsenic and ischemic heart disease, non-malignant respiratory disease, and lung, skin, bladder and kidney cancers. In contrast, inhaled arsenic has been consistently associated only with lung cancer. Evidence for health effects of inhaled arsenic derives mainly from occupational studies that are subject to unique biases that may attenuate or obscure such associations.

OBJECTIVES: Estimate the excess mortality from respiratory cancers, heart disease, and other causes due to occupational arsenic exposure while controlling for confounding using the parametric g-formula.

METHODS: Using a cohort of 8,014 male copper smelter workers hired between 1938 and 1955 and followed through 1990, we estimated the impacts of hypothetical workplace interventions on arsenic exposure on risk of mortality from all causes, heart disease and lung cancer using the parametric g-formula.

RESULTS: We estimate that eliminating arsenic exposure at work would have prevented 22 deaths by age 70 per 1000 workers (95% Confidence intervals: 10, 35). Of those 22 excess deaths, we estimate that 7.2 (95% CI: -1.2, 15) would be due to heart disease, 4.0 (95% CI: -0.8, 8.2) to respiratory cancers, and 11 (0.0, 23) to other causes.

CONCLUSIONS: Our analyses suggest that the excess deaths from causes other than respiratory cancers comprise the majority of the excess deaths caused by inhaled arsenic exposure. Healthy worker survivor bias may have masked such associations in prior analyses. These results emphasize the need for consideration of all exposure routes for upcoming risk assessment by the United States Environmental Protection Agency.

Keil, 2016, 3445650

Study evaluation