THE RELATIONSHIP BETWEEN SELECTED CAUSES OF POSTNEONATAL INFANT-MORTALITY AND PARTICULATE AIR-POLLUTION IN THE UNITED-STATES

Recent studies have found associations between particulate air polluti on and total and adult mortality. The relationship between particulate air pollution and mortality among infants has not been examined in th e United States, This study evaluates the relationship between postneo natal infant mortality and particulate matter in the United States. Ou r study involved analysis of cohorts consisting of approximately 4 mil lion infants born between 1989 and 1991 in states that report relevant covariates; this included 86 metropolitan statistical areas (MSAs) in the United States. Data from the National Center for Health Statistic s-linked birth/infant death records were combined at the MSA level wit h measurements of particulate matter 10 mu m or less (PM10) from the E PA's Aerometric Database, Infants were categorized as having high, med ium, or low exposures based on tertiles of PM10, Total and cause-speci fic postneonatal mortality rates were examined using logistic :regress ion to control for demographic and environmental factors. Overall post neonatal mortality rates were 3.1 among infants with low PM10, exposur es, 3.5 among infants with medium PM10 exposures, and 3.7 among highly exposed infants. After adjustment for other covariates, the odds rati o (QR) and 95% confidence intervals (CI) for total postneonatal mortal ity for the high exposure versus the low exposure group was 1.10 (1.04 , 1.16). In normal birth weight infants, high PM10 exposure was associ ated with respiratory causes [OR = 1.40, (1.05, 1.85)] and sudden infa nt death syndrome [OR = 1.26, (1.14, 1.39)]. For low birth weight babi es, high PM10 exposure was associated, but not significantly, with mor tality from respiratory causes [OR = 1.18, (0.86, 1.61)]. This study s uggests that particulate matter is associated with risk of postneonata l mortality. Continued attention should be paid to air quality to ensu re optimal health of infants in the United States.