Burn Pit Exposure Assessment to Support a Cohort Study of US Veterans of the Wars in Iraq and Afghanistan.

OBJECTIVE:For a cohort study of veterans' health conditions, we conducted an exposure assessment for 109 bases in Iraq and Afghanistan and 17 outside transit site bases. METHODS:The Department of Defense records were used to determine burn pit usage and waste disposal methods for each base in each year during the period of 2001 to 2014. RESULTS:In the final cohort of 475,326 veterans, who had more than 80% of their deployment time characterized by our exposure matrix, only 14.5% were found to have no burn pit exposure. The 2009 Department of Defense regulations on burn pits did produce changes in waste segregation, as well as adding incineration and local disposal of waste. CONCLUSION:Most Iraq and Afghanistan veterans were stationed on bases that had burn pits, although the contents disposed of in the burn pits changed over time.