Industrial air emissions, and proximity to major industrial emitters, are associated with anti-citrullinated protein antibodies

Objective: To determine the association of anti-citrullinated antibodies (ACPA) with the ambient air pollutants fine particulate matter (PM2.5) and sulfur dioxide (SO2). Methods: The CARTaGENE first-wave cohort includes 20,000 general population subjects from Quebec (Canada). On a sample of unselected 1586 subjects, we determined serum, ACPA and performed multivariable logistic regression, for the outcome of positive ACPA, assessing for independent effects of our air pollution variables, adjusting for age, sex, smoking, and French Canadian origin. Two models assessed distance to main industrial emitters of PM2.5, and of SO2, and two models assessed tons of SO2 and of PM2.5 annual emissions. We also assessed associations with PM2.5 regional ambient concentrations estimated with satellite imagery. Results: Adjusted analyses suggested a positive association between annual industrial PM2.5 and SO2 emissions and the presence of ACPA antibodies (OR: 1.02, 95%CI 1.00-1.04 per 10 t of PM2.5 and 100 t of SO2). The data were also consistent with a negative association between the presence of ACPA, and distance to a major industrial emitter of both PM2.5 and SO2. We found no association with PM2.5 estimates of ambient levels. Conclusions: These analyses suggest that exposure to industrial emissions of air pollutants is related to ACPA positivity.