David A. Butler – författare

Overwhelming evidence exists that exposure to outdoor fine particulate matter (PM2.5) is associated with a range of short-term and chronic health impacts, including asthma exacerbation, acute and chronic bronchitis, heart attacks, increased susceptibility to respiratory infections, and premature death, with the burden of these health effects falling more heavily on underserved and marginalized communities. Although less studied to date, indoor exposure to PM2.5 is also gaining attention as a potential source of adverse health effects, particularly given that Americans spend 90 percent of their lives indoors and indoor PM2.5 levels can exceed outdoor levels.

To better understand the sources of indoor PM2.5, the possible health effects of exposure to indoor PM2.5, and engineering approaches and interventions to reduce those exposure risks, the National Academies of Sciences, Engineering, and Medicine convened a virtual workshop, Indoor Exposure to Fine Particulate Matter and Practical Mitigation Approaches, on April 14, 21, and 28, 2021. The workshop focused on exposures that occur in residential and school buildings and on existing and practical mitigation technologies and approaches. This publication summarizes the presentation and discussion of the workshop.

The U.S. Environmental Protection Agency (EPA) defines PM as a mixture of extremely small particles and liquid droplets comprising a number of components, including "acids (such as nitrates and sulfates), organic chemicals, metals, soil or dust particles, and allergens (such as fragments of pollen and mold spores)". The health effects of outdoor exposure to particulate matter (PM) are the subject of both research attention and regulatory action. Although much less studied to date, indoor exposure to PM is gaining attention as a potential source of adverse health effects. Indoor PM can originate from outdoor particles and also from various indoor sources, including heating, cooking, and smoking. Levels of indoor PM have the potential to exceed outdoor PM levels.

Understanding the major features and subtleties of indoor exposures to particles of outdoor origin can improve our understanding of the exposure–response relationship on which ambient air pollutant standards are based. The EPA''s Indoor Environments Division commissioned the National Academies of Sciences, Engineering, and Medicine to hold a workshop examining the issue of indoor exposure to PM more comprehensively and considering both the health risks and possible intervention strategies. Participants discussed the ailments that are most affected by particulate matter and the attributes of the exposures that are of greatest concern, exposure modifiers, vulnerable populations, exposure assessment, risk management, and gaps in the science. This report summarizes the presentations and discussions from the workshop.

Military operations produce a great deal of trash in an environment where standard waste management practices may be subordinated to more pressing concerns. As a result, ground forces have long relied on incineration in open-air pits as a means of getting rid of refuse. Concerns over possible adverse effects of exposure to smoke from trash burning in the theater were first expressed in the wake of the 1990–1991 Gulf War and stimulated a series of studies that indicated that exposures to smoke from oil-well fires and from other combustion sources, including waste burning, were stressors for troops. In January 2013, Congress directed the Department of Veterans Affairs (VA) to establish and maintain a registry for service members who may have been exposed to toxic airborne chemicals and fumes generated by open burn pits.

Assessment of the Department of Veterans Affairs Airborne Hazards and Open Burn Pit Registry analyzes the initial months of data collected by the registry and offers recommendations on ways to improve the instrument and best use the information it collects. This report assesses the effectiveness of the VA''s information gathering efforts and provides recommendations for addressing the future medical needs of the affected groups, and provides recommendations on collecting, maintaining, and monitoring information collected by the VA''s Airborne Hazards and Open Burn Pit Registry.

On August 18-19, 2022, the National Academy of Engineering (NAE) held a symposium to explore how support of fundamental engineering and engineering education research by the National Science Foundation (NSF) has led to positive societal and economic impacts. The symposium - which was sponsored by the NSF Directorate for Engineering - was held to provide input to the NAE Committee on Extraordinary Engineering Impacts on Society as part of a larger effort to develop clear, compelling narratives for the public about the sources and effects of engineering innovations. Speakers at the symposium shared their personal stories and provided insights on how engineers influence not only technology and the national infrastructure but the economy, population health, manufacturing, disaster resilience, and many other aspects of daily life. This publication summarizes the presentations and discussion of the symposium.