Ambient Air Pollution and Cardiac Malformations; A Register-Based Spatio-temporal Analysis

ISEE-0120 Objective: To investigate the association between maternal exposure to ambient air pollution and the occurrence of congenital heart disease (CHD). Methods: This case-control study used registry-based data on all CHD cases arising in the population of the Northeast England (1985–2003). Exposure assessment and risk analysis were performed as two sub-studies. Sub-study I used exposure data on PM10, SO2, NO2, NO, CO, and ozone obtained from six automatic monitors for the period 1993–2003. Each study participant was assigned weekly average of pollutant levels measured by the closest operational monitor to the maternal residential postcode. Sub-study II used data on black smoke (BS) and SO2 obtained from 56 non-automatic monitors for the period 1985–1996. A two-stage spatiotemporal modeling approach was used to predict ambient pollutant levels at maternal residential postcodes for each week of their pregnancy. Controls were matched to cases by year of birth with a control/case ratio of four to one. Single and multiple pollutant logistic regression models were used to quantify the adjusted odds ratios of exposure to air pollution and occurrence of each ICD-10 class of CHD and for the five most frequent individual CHD. Adjustment was performed for the year of birth, socioeconomic status, sex, season of conception, degree of urbanity. In sub-study II, a further analysis was carried out by using 1000 simulated exposure scenarios. Results: In sub-study I, ventricular septal defect and congenital malformations of cardiac septa were found to be associated with exposure to CO and NO. Increased risk of congenital pulmonary stenosis and tetralogy of Fallot were detected due to exposure to CO and NO respectively. Sub-study II detected a weak association between maternal exposure to BS and congenital malformations of cardiac chambers and connections. Conclusion: This study has demonstrated that maternal exposure to ambient air pollution increases the risk of specific CHD.