Ischemic heart disease mortality and PM(3.5) in a cohort of autoworkers.

BACKGROUND

Increased risk of ischemic heart disease (IHD) has been associated with particulate matter (PM) from air pollution. Yet evidence of increased risk associated with higher workplace exposures is scant.

METHODS

We examined the exposure-response relationship between IHD mortality and PM(3.5) (<3.5 µm diameter) from current and cumulative exposure to straight metalworking fluid in a cohort of 39,412 autoworkers followed from 1941 to 1995. Age, calendar year of follow up, sex, race, and plant were included in each model.

RESULTS

To address the decrease in polycyclic-aromatic hydrocarbon (PAH) content in the straight metalworking fluid over time, analyses were stratified by calendar time. Increased risk of IHD mortality was associated with current exposure to PM(3.5) before 1971 and with cumulative exposure to PM(3.5) after 1971.

CONCLUSIONS

Results provide modest evidence that occupational exposure to fine PM from straight fluids, especially fluid with higher PAH, may increase the risk of IHD mortality.