Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR); and established databases. The committee did not re-examine the underlying data or methods for those sources but relied on them as established sources of health-effects information.
For such chemical mixtures as burn pit emissions, toxicity and other health-effects data on mixtures themselves are generally scarce or nonexistent. Therefore, the committee sought information on health effects in other populations that were exposed to chemical mixtures that might include at least some of the constituents of burn pit emissions. The committee gave special attention to studies of other military populations, wildland and urban firefighters, municipal incinerator workers, and residents who lived near municipal waste incinerators. Some of those studies provide data on populations that had characteristics that were similar to those of the people at JBB—for example, they were young (in 2008, 62% of active-duty personnel were 18–30 years old), healthy (deployed personnel must meet health standards), predominantly male (only 14–15% of active-duty personnel are women), and exposed to similar pollutants (chemical mixtures produced by burning).
On the basis of its data collection and literature review, the committee summarized key findings on materials burned at JBB and other military burn pit locations, health-effects data on the combustion products detected at JBB, and studies of health effects in non-Balad populations potentially exposed to similar chemicals. The committee commented on its confidence in those findings and on their utility in providing the VA with information for medical followup and future studies. The committee also considered the possible effects of coexposure to local and regional air pollution from sources other than the JBB burn pit.
The committee identified gaps in the information available on possible health effects of exposure to burn pits and discussed design and feasibility issues related to an epidemiologic study of health effects to address the gaps.
USE OF MILITARY BURN PITS
Open-air waste burning has long been used by the military when other waste-disposal options have not been available. Technologic advances in recent military conflicts mean that new items are being burned—plastic bottles and electronics, for example—and the burning of such items presents new health risks.
The uncontrolled burning of waste in pits has been the primary solid-waste management solution in Afghanistan and Iraq from the beginning of the conflicts in 2001 and 2003, respectively. The use of burn pits by the U.S. military in those countries was restricted in 2009. By December 31, 2010, their use in Iraq had gradually been phased out, but it continues in Afghanistan, where 197 burn pits were operating as of January 2011.
The DoD estimates that an average of 8–10 lb of waste is generated each day by each person in theater. On the basis of the average populations of large bases in Iraq and Afghanistan (those with more than 1,000 personnel), an average of about 30–42 tons of solid waste per day might be produced on a base. JBB, with a population that sometimes surpassed 25,000—including U.S. troops, host-nation soldiers, coalition troops, civilians, and contractors—burned perhaps 100–200 tons of waste a day in 2007. In 2009, when three incinerators were operational at JBB, about 10 tons of waste was burned daily in the pit; the burn pit ceased operation as of October 1, 2009. A 2010 Army Institute of Public Health study of burn pits in Iraq and Afghanistan reported that large bases burned waste that consisted generally of 5–6% plastics, 6–7% wood, 3–4% miscellaneous noncombustibles, 1–2% metals, and 81–84% combustible materials (further details on waste composition were not available).
In response to personnel complaints of odor, poor visibility, and health effects attributed to burn pit emissions, the U.S. Army Center for Health Promotion and Preventive Medicine (CHPPM, now the U.S. Army Public Health Command) and the Air Force Institute for Operational Health conducted ambient-air sampling and screening health-risk assessments of burn pit exposures at JBB in 2007 and again in 2009. The assessments were designed to detect potentially harmful inhalation exposures of personnel at JBB to chemicals expected to be released by the burn pit. The CHPPM reports indicated that the risk of acute health effects of all chemicals detected, except coarse particulate matter (PM), was low and that long-term health risks were “acceptable” (that is, for noncancer endpoints a hazard index of less than 1.0; for cancer endpoints a risk ranging from 1 in 10,000 to 1 in 1,000,000 or lower).