Congenital anomalies in a high environmental risk area. A case control study in Brindisi (Southern Italy)

Maternal exposure to ambient pollution has been increasingly linked to the risk of congenital anomalies (CAs) in fetus and newborns. Recently, a descriptive study (Gianicolo et al., 2012) revealed an increased prevalence of total CAs and in particular, congenital heart diseases (CHDs) and ventricular septal defects (VSDs) in Brindisi, both at local level and in comparison with the pool of EUROCAT registries. Due to the presence of many sources of pollution near the urban area, in the 1980s, Brindisi and surrounding municipalities were identifi ed by the Italian Ministry of Environment as an "area at high risk of environmental crisis". Epidemiological studies have revealed several critical situations in terms of increasing rates of mortality and morbidity directly or potentially associated with environmental and occupational exposure to pollutants. This population-based case-control study investigated the association of maternal exposure to air pollutants sulfur dioxide (SO2) and total suspended particulate matter (TSP) with the risk of CA. Cases were newborns to mothers residing in Brindisi between 2001 and 2010, up to 28 days of age, and discharged with a diagnosis of CA. Cases and controls were individually matched according to sex, socioeconomic status of the census area of residence of the mother, and year of conception. Four controls were extracted for each case. Concentration data from monitoring stations data were used to estimate air pollution exposure. Each case and control were assigned pollutant concentration values (weeks 3-8 of pregnancy). Exposure as both continuous and categorical variable was considered and a conditional logistic regression model was constructed to quantify the odds ratios of exposure to air pollutants and the occurrence of total CAs, CHDs and VSDs. We found exposure to SO2 to be associated with CHDs and VSDs. Findings for TSP were less consistent.