The purpose of this study was to estimate exposure of pregnant women in Poland to fine particulate matter [
2.5 µm in diameter (PM
2.5)] and to assess its effect on the birth outcomes. The cohort consisted of 362 pregnant women who gave birth between 34 and 43 weeks of gestation. The enrollment included only nonsmoking women with singleton pregnancies, 18-35 years of age, who were free from chronic diseases such as diabetes and hypertension. PM
2.5 was measured by personal air monitoring over 48 hr during the second trimester of pregnancy. All assessed birth effects were adjusted in multiple linear regression models for potential confounding factors such as the size of mother (maternal height, prepregnancy weight), parity, sex of child, gestational age, season of birth, and self-reported environmental tobacco smoke (ETS). The regression model explained 35% of the variability in birth weight (ß = -200.8,
p = 0.03), and both regression coefficients for PM
2.5 and birth length (ß = -1.44,
p = 0.01) and head circumference (HC; ß = -0.73,
p = 0.02) were significant as well. In all regression models, the effect of ETS was insignificant. Predicted reduction in birth weight at an increase of exposure from 10 to 50 µg/m
3 was 140.3 g. The corresponding predicted reduction of birth length would be 1.0 cm, and of HC, 0.5 cm. The study provides new and convincing epidemiologic evidence that high personal exposure to fine particles is associated with adverse effects on the developing fetus. These results indicate the need to reduce ambient fine particulate concentrations. However, further research should establish possible biologic mechanisms explaining the observed relationship.
Key words: air pollutants, cohort study, fetal growth, pregnancy, prenatal exposure.
Environ Health Perspect 112: 1398-1402 (2004). [Online 21 June 2004]
Address correspondence to W. Jedrychowski, Epidemiology and Preventive Medicine, Medical College, Jagiellonian University, 7A, Kopernika St., Krakow, Poland. Telephone: 48-12-423-1003. Fax: 48-12-422-8795. E-mail: myjedryc@cyf-kr.edu.pl
The study received funding from 5 RO1 ES0165 from the National Institute of Environmental Health Sciences and from the Gladys and Roland Harriman Foundation.
The authors declare they have no competing financial interests.
Received 2 March 2004; accepted 21 June 2004.
