Air Pollution Levels and Children’s Lung Health: How Low Do We Need to Go?

Details

• Personal Author:
  Kaufman JD ; Sack CS
• Description:
  During the 25 years since the last amendment to the Clean Air Act, ambient air pollution concentrations in the United States have decreased significantly. These reductions represent a major public health success of the regulations resulting from this law. This poses a question: Have we reached or are we approaching a point at which health effects are no longer attributable to the primary air pollutants? The existing body of evidence regarding respiratory health effects of air pollutants has largely been based on research conducted at higher concentrations than those now experienced in the United States. Respiratory health effects of air pollutants occur throughout the lifespan, although children are considered an especially susceptible population. Children are exposed to a higher burden of pollutants because of their greater ventilatory rate and propensity to spend more time outdoors, engaged in physical activity. They are also exposed at a vulnerable stage, when the immune and metabolic systems are less mature and the lungs are rapidly developing. ... In this issue of the Journal, Rice and colleagues (pp. 881-888) present an analysis within a well-designed prospective cohort to assess whether long-term ambient air pollution adversely affects lung function, even after policy changes that resulted in improvements in air quality. In contrast to other studies, the authors were able to characterize the cohort and potential confounders from birth, they used advanced modeling of exposures to air pollution within a city and over time, and they used robust measurements of lung function by including both pre- and post-bronchodilator spirometry. Their study suggests that even pollutant concentrations that are below current U.S. Environmental Protection Agency standards (12 microg/m3 annual average) are associated with a decrease in spirometric measures. The findings of Rice and colleagues provide compelling additional evidence that it is timely to reevaluate the effects of lower levels of air pollutants on human health. Although carefully conducted, there are limitations to the work that should be noted, in addition to the usual caveats regarding observational rather than experimental designs and the risk for residual confounding. The study was performed in a relatively homogenous population in Boston, and the findings may not be generalizable to a population in which other determinants of lung function may predominate. The outcome of lung function is only measured once in study participants, so the time course of effects is unknown, and it is uncertain whether these changes represent a reversible effect versus a permanent change in lung development that leads to a lower adult maximum in lung function. These important findings are from a novel study combining modern modeling of exposures to air pollution with robust measurements of lung function, conducted in a community with pollutant levels now lower than Environmental Protection Agency standards. This adds to the urgency for more work to understand the effects of these low-level exposures on human health. Is there a safe level of exposure to air pollutants? These findings appear even as communities in rapidly developing economies such as China and India are experiencing increasing and dramatic high levels of air pollutant exposure, with some locations reporting concentrations more than an order of magnitude greater than those observed in this study in Boston. Taken together, the questions about the "shape" of the relationship between exposure and health are urgent and important, with implications for research and public policy. It appears that benefits of pollution control accrue at all levels of exposure, and we do not yet know the levels that will avoid important impacts on health. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Air Pollution Environmental Exposure Environmental Pollution Lung Occupational Health Particulate Matter Respiratory System Safety
• Keywords:
  Air Pollutants Air Pollution Children Environmental Pollution Health Effects Lung Function Particulates Respiratory Health
• ISSN:
  1073-449X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  193
• Issue:
  8
• NIOSHTIC Number:
  nn:20063682
• Citation:
  Am J Respir Crit Care Med 2016 Apr; 193(8):819-820
• Federal Fiscal Year:
  2016
• Performing Organization:
  University of Washington
• Peer Reviewed:
  False
• Start Date:
  20050701
• Source Full Name:
  American Journal of Respiratory and Critical Care Medicine
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:17d03737b7c5c0689ea03def54fc5b364c16573baa6ad13b66ce193e7325eb8078c2193df6cb1a88a6b936432fd7b371054cc21d952afa4717f59613bb1bf668
• Download URL:
  https://stacks.cdc.gov/view/cdc/222243/cdc_222243_DS1.pdf
• File Type:
  [PDF - 430.63 KB ]