Indoor Exposure to Particulate Matter - the State of the Science

The health effects of outdoor exposure to particulate matter (PM) are well-established and are used to set health-based National Ambient Air Quality Standards (NAAQS). Although much less studied to date, indoor exposure to PM is gaining attention as a potential source of adverse health effects. PM found indoors can be particles of outdoor origin that migrate indoors, or from indoor sources. Indoor PM sources include combustion—cooking, appliances, and like—and occupant activities, notably secondhand smoke. Indoor PM levels have the potential to exceed outdoor levels and NAAQS. In response to a request from the US Environmental Protection Agency, the Institute of Medicine of the National Academies of Sciences, Engineering, and Medicine is conducting a workshop that will address the potential health risks of indoor exposure to particulate matter and the state of scientific understanding regarding them, focusing on PM2.5 and smaller exposures. The workshop will feature invited presentations and discussions regarding the health conditions that are most affected by PM, the attributes of the exposures that are of greatest concern, exposure modifiers, vulnerable populations, exposure assessment, risk management, and gaps in the science. It will take place in February 2016. An Academies report summarizing the workshop will be released in Summer 2016. This presentation summarizes the results of the workshop, reviewing the issues regarding indoor PM exposure and health, and discussing the major unknowns and research needs identified.