Table 8.
Comparisons Between This Study and Previous Studies Investigating the Effects of Air Pollution Exposure on Congenital Heart Defects.
| Study location (time period) | Study design (No. of births) | Pollutants studied | Exposure window | Air pollutant exposure estimation methods | Regression models (No. of confounders) | Main results related to congenital heart defects | Study |
|---|---|---|---|---|---|---|---|
| Lanzhou, China (2009–2012) | Cohort (8969) | PM10, NO2, SO2 | week 3–8; 1st trimester; entire pregnancy | Inverse distance weighting to estimate levels at work and residence. Accounted for residential mobility. | Logistic regression (12) | Significant associations for: PM10 exposures during 1st trimester and entire pregnancy and pooled cases; NO2 exposures during entire pregnancy with pooled cases. | This study |
| Southern California, US (1987–1993) | Case-control (14,198) | CO, NO2, O3, PM10 | 1st, 2nd, and 3rd month; 2nd and 3rd trimester; 3-month period prior to conception | Assigned most relevant monitor to each zip code of maternal residence | Logistic regression (10) | Does-response patterns for: 2nd-month CO and ventricular septal defects; 2nd month O3 exposure and aortic artery and valve defects, pulmonary artery and valve anomalies, and conotruncal defects. | Ritz et al. (2002) |
| Texas, US (1997–2000) | Population-based case-control (7381) | CO, NO2, O3, PM10 | week 3–8 | Closest monitor | Logistic regression (14) | Significant associations for: CO and tetralogy of Fallot; PM10 and isolated atrial septal defects; SO2 and isolated ventricular septal defects. | Gilboa et al. (2005) |
| Georgia, US (1986–2003) | Cohort (715,500) | CO, NO2, O3, PM10, SO2 | week 3–7 | Central monitoring station | Poisson generalized linear models (2) | Significant association for PM10 and patent ductus arteriosus. | Strickland et al. (2009) |
| Brisbane, Australia (1998–2004) | Case-control (150,308) | CO, NO2, O3, PM10, SO2 | week 3–8 | Closest monitor | Conditional logistic regression (7) | No association between air pollution and cardiac defects. | Hansen et al. (2009) |
| Northern Health Region, UK (1985–1990) | Case-control (245,825) | Black smoke, SO2 | 1st trimester | Average from monitors within 10 km of residence | Logistic regression (3) | Significant negative association for SO2 and congenital heart disease. | Rankin et al. (2009) |
| Northeast England, UK (1985–1996) | Case-control (12,688) | Black smoke, SO2 | week 3–8 | Estimation of weekly exposure using 2-stage spatiotemporal model | Logistic regression (5) | Significant association for BS and congenital malformations of cardiac chambers and connections. | Dadvand et al. (2010) |
| Northeast England, UK (1993–2003) | Case-control (19,036) | CO, NO2, O3, PM10, SO2, NO | week 3–8 | Closest monitor to residential postcode | Logistic regression (5) | Significant associations for: CO and NO and ventricular septal defect and cardiac septa malformations; CO and congenital pulmonary valve stenosis; NO and pooled cases. | Dadvand et al. (2011) |
| UK (1991–1999) | Case-control (759,993) | NO2, PM10, SO2 | 20 weeks | Annual mean at census ward level | Poisson regression (3) | Significant association for SO2 and tetralogy of Fallot. | Dolk et al. (2009) |
| Tel-Aviv region, Israel (2000–2006) | Case-control (135,527) | CO, NO2, O3, PM10, PM2.5, SO2 | week 3–8 | Weekly estimates based on inverse distance weighting | Logistic regression (8) | Significant association for PM10 and pooled cases. Significant inverse association for PM2.5 and isolated patent ductus arteriosus. | Agay-Shay et al. (2013) |
| San Joaquin Valley, CA, US (1997–2006) | Population-based case-control (1,671) | CO, NO, NO2, PM10, PM2.5, O3 | first 2 months | Inverse distance-squared weighting; traffic density indicators representing traffic counts within 300m of early pregnancy residence. Accounted for residential mobility. | Logistic regression (3) | Significant associations for: PM10 with pulmonary valve stenosis and perimembranous ventricular septal defects; PM2.5 and transposition of the great arteries; traffic density with muscular ventricular septal defects and perimembranous ventricular septal defects. Inverse associations for: PM2.5 and perimembranous ventricular septal defects; CO and secundum atrial septal defects. | Padula et al. (2013) |
| Barcelona, Spain (1994–2006) | Case control (5,238) | NOx, NO2, PM10, PM2.5, PM10–2.5, PM2.5 absorbance | week 3–8 | Land use regression models. | Logistic regression (4) | Significant association for NO2 and coarctation of the aorta. | Schembari et al. (2014) |
| Nine states, US (1997–2006) | Case control (7,960) | CO, NO2, O3, SO2, fine and coarse PM | week 2–8 | Closet monitor within 50 km to residence | Hierarchical regression (3) | Positive associations for: NO2 and coarctation of the aorta and pulmonary valve stenosis; fine PM and hypoplastic left heart syndrome. Negative association for fine PM and atrial septal defects. | Stingone et al. (2014) |
| Texas (2002–2006) | Population-based case-control (1,423,483) | PM2.5, O3 | 1st trimester | Hierachical Bayesian model combining data from air monitors with modeled air pollution estimates from CMAQ. Accounted for residential mobility for NBDPS database. | Logistic regression (5) | Significant inverse association for O3 and septal heart defects. | Vinikoor-Imler et al. (2015) |