Based on that report, the Volume 11 committee focused on several specific pollutant categories. The following section explores the literature pertaining to the reproductive, developmental, and transgenerational effects of PM, PAHs, and PCDDs/PCDFs. Given the overlap between VOCs and solvents, relevant VOCs are discussed in the chapter on solvents.
The Volume 3 committee reviewed the literature on combustion products through 2004. It approached its task by identifying the most common components in combustion emissions, including PM, sulfur dioxide (SO2), ozone (O3), nitrogen oxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), hydrogen sulfide (H2S), and VOCs and then assessing the possible health effects associated with each of these agents. The Volume 3 committee considered preterm birth, low birth weight, very low birth weight, intrauterine growth retardation, birth defects, and childhood cancers as relevant outcomes. These outcomes were assessed in epidemiologic studies of ambient air pollution—frequently conducted in or near heavily polluted cities—or in case-control studies based on residence or parental occupation. Generally, these studies were limited by a lack of control for other risk factors, such as smoking, and the use of overly broad exposure classifications. The Volume 3 committee concluded that there was:
- inadequate/insufficient evidence of an association between parental combustion product exposure and any childhood cancers or any birth defects,
- limited/suggestive evidence of an association between combustion product exposure during pregnancy and preterm birth,
- limited/suggestive evidence of an association between combustion product exposure during pregnancy and low birth weight or intrauterine growth retardation, and
- insufficient/inadequate evidence of an association at any specific time during pregnancy (e.g., first trimester) and preterm birth, low birth weight, or intrauterine growth retardation (IOM, 2005).
The 2011 IOM report Long-Term Health Consequences of Exposure to Burn Pits in Iraq and Afghanistan examined the epidemiologic literature on firefighters and people living or working near incinerators and health endpoints identified by authoritative reviews (e.g., the Environmental Protection Agency [EPA], the Agency for Toxic Substances and Disease Registry [ATSDR], the National Institute for Occupational Safety and Health, and the Hazardous Substances Database) of the 56 chemicals that were measured above the detection limit in burn pit environmental sampling data. Because data on the health of veterans or active-duty service members who were exposed to burn pits were scant, the committee reviewed studies of firefighters and incinerator workers because of their relatively similar exposure to combustion products. That committee found that there were known reproductive and developmental toxicants among the burn pit chemicals and that they should be further studied. The literature at the time included no “key” studies on reproductive or developmental outcomes, and “supporting” studies presented mixed results or showed no elevated risks. Thus, that committee concluded that there was “inadequate/insufficient evidence to determine whether an association exists between parental exposure to combustion products and adverse effects in their children and other adverse reproductive and perinatal outcomes in veterans, firefighters, or people living/working near incinerators” (IOM, 2011, p. 88).