Ambient ultrafine particles and congenital heart defects

Abstract

OPS 56: Ultrafine particles exposure and health effects, Beatrix Theater, August 27, 2019, 4:30 PM - 5:30 PM Background & Aim: Cardiovascular malformations account for nearly one-third of all congenital anomalies, making these the most common type of birth defects. Little is known regarding the role of ambient ultrafine particles (<0.1 μm) (UFPs) on the risk of congenital heart defects. This population-based study examined the association between prenatal exposure to UFPs and congenital heart defects. Methods: A total of 158,743 singleton live births occurring in the City of Toronto, Canada between April 1st 2006 and March 31st 2012 were identified from a birth registry. Associations between exposure to UFPs between the 2nd and 8th week post conception, an important period when the foetal heart begins to form, and congenital heart defects (CHDs) identified at birth were estimated using random-effects logistic regression models. Adjustment was done for personal- and neighborhood-level covariates. We investigated both single- and multi-pollutant models accounting for co-exposures to PM2.5, NO2 and O3. Results: A total of 511 CHDs were identified. In adjusted models, exposure to UFPs during weeks 2 to 8 of pregnancy was associated with ventricular septal defect (Odds Ratio (OR) per interquartile (IQR) increase = 1.31, 95% CI: 1.06 - 1.81) and coarctation of the aorta (OR per IQR increase = 2.42, 95% CI: 1.02 – 6.11). We also found an association between NO2 and tetralogy of Fallot (OR per IQR increase = 2.30, 95% CI: 1.06 – 5.91). Conclusions: This is the first study to evaluate the association between prenatal exposure to UFPs and the risk of CHDs. Exposure to UFPs during a critical period of foetal cardiac development was linked to the risk of specific types of CHDs.