Perinatal and infant mortality and low birth weight among residents near cokeworks in Great Britain

With growing evidence of the adverse health effects of air pollution-especially fine particulates-investigators must concentrate on the fetus, neonate, and infant as potentially vulnerable groups. Cokeworks are a major source of smoke and sulfur dioxide. In the current study, the authors investigated whether populations residing near cokeworks had a higher risk of adverse perinatal and infant outcomes. Zones of 7.5-km radius around 22 cokeworks in Great Britain were studied, within which the authors assumed that exposure declined from highest levels within 2 km to background levels. Routinely recorded birth and death data for Great Britain during the period 1981-1992 were analyzed. Each individual record had a postcode that referred to a small geographical area of typically 15-17 addresses. The authors calculated expected numbers on the basis of regional rates, stratified by year, sex, and a small-area socioeconomic deprivation score. For all cokeworks combined, the observed/expected ratio (95% confidence intervals within parentheses) within 2 km of cokeworks was 1.00 (0.95, 1.06) for low-birth-weight (i.e., < 2,500 g) infants; 0.94 (0.78, 1.12) for still births; 0.95 (0.83, 1.09) for infant mortality; 0.86 (0.72, 1.03) for neonatal mortality; 1.10 (0.90, 1.33) for postneonatal mortality; 0.79 (0.30, 1.46) for respiratory postneonatal mortality; and 1.07 (0.77, 1.43) for postneonatal Sudden Infant Death Syndrome. Respiratory postneonatal mortality was low throughout the entire 0-7.5-km study area (observed/expected = 0.74 [0.61, 0.88]). There was no statistically significant decline in risk with distance from cokeworks for any of the outcomes studied. The authors concluded that there was no evidence of an increased risk of low birth weight, stillbirths, and/or neonatal mortality near cokeworks, and there was no strong evidence for any association between residence near cokeworks and postneonatal mortality. One must remember, however, the limited statistical power of the study to detect small risks.