It Starts at the Beginning: Effect of Particulate Matter In Utero

Details

• Personal Author:
  Goss CH ; Sack C ; Goss CH ; Sack C
• Description:
  There is convincing evidence that exposure to ambient air pollution is associated with increased asthma symptoms, exacerbations, and a decline in lung function in children. Recent studies suggest this relationship may begin in utero, when cells are particularly sensitive to the oxidative damage caused by environmental toxins. The timing of exposure during gestation may be crucial in determining specific effects on immune system development and the different stages of fetal lung maturation. ... In this issue of the Journal, Hsu and colleagues (pp. 1052-1059) present a well-designed prospective cohort study of 736 full-term children born in Boston, Massachusetts, to assess whether in utero exposure to ambient air pollution is associated with the development of asthma. In contrast to other studies, the authors were able to address the effect of exposure timing by estimating weekly maternal levels of particulate matter with diameter ≤2.5 microg (PM2.5), a major component of traffic-related air pollution, throughout gestation. For exposure assessment, they used a well-validated satellite-based model with land use regression and spatial temporal resolution. Their final statistical models adjusted for a number of potential confounders, including measurements of socioeconomic status, allergen exposures, and household crowding. ... Although Hsu and colleagues used sophisticated models of pollution exposure with fine temporal resolution, postnatal exposure to air pollution correlates strongly with prenatal levels, and it may be difficult to disentangle these interrelated effects. Controlled exposure studies in mice have found that although pre and postnatal PM2.5 exposure leads to significant alteration of alveolar structure and lung elastic properties, prenatal exposure alone did not alter lung function. These data appear to conflict with the findings of the study by Hsu. In animal studies, one can exactly control the timing and exposure, whereas in human observations, we can merely try to capture as best as possible both the timing and dose of exposure. In contrast to animal exposure studies, humans are born into the same environment as they develop, and they will continue to be exposed to similar pollutants. Overall, this study adds significantly to the body of literature that documents the adverse effects of these early gestational exposures. When trying to weigh the strengths of associations noted in observational studies, one should evaluate the presence of biologic plausibility, size of the effect (the larger the effect, the more likely it could represent a true association), temporal relationship (the risk factor was determined prior to the determination of the outcome), and the relation to other existing literature. In this case, the authors present a compelling biologic model, appropriate temporal association, and supporting existing literature. These data support the potential to mitigate against harmful exposures in utero by knowing the time at which the fetus may be at highest risk. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Air Pollution Asthma Asthma, Occupational Environmental Exposure Environmental Pollution Occupational Health Particulate Matter Pregnancy Safety
• Keywords:
  Air Pollutants Air Pollution Environmental Pollution In Utero Exposure Particulates Prenatal Exposure
• ISSN:
  1073-449X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Volume:
  192
• Issue:
  9
• NIOSHTIC Number:
  nn:20063681
• Citation:
  Am J Respir Crit Care Med 2015 Nov; 192(9):1025-1026
• 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:d720345dca7f45a469511b7ef77a124f4c8a64a0c592e0f4031d0e299c6b1313b2b28a3eb11cdd3f16b3c15b606fe173939e1cd781d5945c1021dba378858b93
• Download URL:
  https://stacks.cdc.gov/view/cdc/222242/cdc_222242_DS1.pdf
• File Type:
  [PDF - 441.29 KB ]