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A TIME SERIES ANALYSIS OF AIR POLLUTION AND PRE-TERM BIRTH IN PENNSYLVANIA, 1997-2001
Citation:
Sagiv, S., P Mendola, D. Loomis, A. H. Herring, L Neas, D. A. Savitz, AND C. Poole. A TIME SERIES ANALYSIS OF AIR POLLUTION AND PRE-TERM BIRTH IN PENNSYLVANIA, 1997-2001. ENVIRONMENTAL HEALTH PERSPECTIVES. National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, NC, 113(5):602-06, (2005).
Impact/Purpose:
to investigate the effect of ambient outdoor particulate matter on risk for preterm delivery
Description:
Background: Preterm delivery can lead to serious infant health outcomes including death and life-long disability. Small increases in preterm delivery risk in relation to air pollution have been reported, but prior investigations may have inadequately controlled for individual factors, such as maternal smoking.
Methods: We conducted a time-series analysis, which controls for these individual factors by design, to investigate the effect of ambient outdoor particulate matter with diameter of 10 micrometers or less (PM10) and sulfur dioxide (SO2) on risk for preterm delivery. Daily counts of preterm births were obtained from birth records in four Pennsylvania counties from 1997 through 2001.
Results: We observed increased risk for preterm delivery with exposure to PM10 and SO2 in the six weeks before birth (Risk Ratio=1.10; 95% CI: 1.01, 1.19 per 50 ug/m3 increase in PM10 and RR =1.20, 95% CI: 1.04, 1.39 per 15 ppb SO2 increase, respectively), adjusting for long-term seasonal trends, co-pollutants, and offsetting by the number of live births in the population. An acute effect on preterm delivery was observed with exposure to PM10 two days before birth (RR =1.11, 95% CI: 1.00, 1.22), adjusting for covariates, as well as temperature, dew point temperature and day of the week.
Conclusions: These findings provide evidence of a small increase in preterm birth risk with exposure to PM10 and SO2 in the six-weeks preceding birth and with PM10 two days before birth. Results from this time-series analysis of air pollution and preterm delivery are consistent with prior investigations using conventional analyses.
MESH heading key words: infant, premature, pregnancy, air pollution, epidemiology