Airborne dioxins, furans and polycyclic aromatic hydrocarbons exposure to military personnel in Iraq

Objectives: The objective was to utilize the ambient concentrations of polycyclic aromatic hydrocarbon (PAH), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) measured at Joint Base Balard in Iraq in 2007 to identify the spatial patterns of exposure to these species and to identify and apportion the likely sources. Methods: The ratios of the measured species were compared to literature data for open burning of simulated military wastes and other likely sources. Using the multiple site measurements on specific days, contour maps have been drawn using inverse distance weighting (IDW). Positive Matrix Factorization (PMF) was applied to the data to obtain the chemical profiles and contribution time series of the PAHs, PCDDs, and PCDFs. Conditional probability function (CPF) analyses were performed to assess the source directionality relative to the monitoring sites Results: These analyses point to multiple sources of the PAH and PCDD/PCDF compounds including the burn pit (primarily a source of PCDD/PCDFs), the transportation field (primarily as source of PAHs) and other sources of PAHs that might include aircraft (fixed wing and helicopter), space heating, and diesel power generation. These three source types were identified and apportioned. The CPF plots were consistent with the assigned source types. Conclusions: The ambient PAH and PCDD/PCDF concentration data provided insights into the identities and locations of their multiple sources. The PCDDs and PCDFs originated primarily from the burn pit and were highly focused in that area. Higher molecular weight PAHs were associated with vehicle emissions while the aircraft emissions were enriched in low molecular weight PAHs.