Content area
Full text
Introduction
A growing body of epidemiological literature has suggested an association between ambient particulate matter (PM) exposure and fetal anomalies, particularly cardiovascular malformations. Evidence has indicated associations between in utero exposure to PM with an aerodynamic diameter ≤10μm (PM10) and the prevalence of fetal cardiovascular malformations, that is to say, associations between PM10 and ventricular septal defects, pulmonary valve stenosis (Padula et al. 2013), patent ductus arteriosus (Strickland et al. 2009), and multiple congenital heart defects (Agay-Shay et al. 2013). A meta-analysis of air pollutant–anomaly combinations found that PM10 exposure was related to an increased risk of atrial septal defects (Vrijheid et al. 2011). Evidence from a line of studies, however, failed to demonstrate an association between PM10 and fetal cardiovascular malformations (Ritz et al. 2002; Schembari et al. 2014; Stingone et al. 2014), and no definite link was indicated between ambient total suspended particles and congenital heart diseases in a study performed in Brindisi, Italy (Gianicolo et al. 2014). An inverse association was reported between PM10 and ventricular septal defects (Hansen et al. 2009) and between fine particulate matter (PM2.5; with an aerodynamic diameter ≤ 2.5 μm) and atrial septal defects (Stingone et al. 2014), ventricular septal defects (Padula et al. 2013), and isolated patent ductus arteriosus (Agay-Shay et al. 2013). These inconsistent results may be attributed to heterogeneity in the sources, components, and exposure levels of PM, to the methods used, and to differences in demography, topography, meteorology, socioeconomic status, and individual lifestyle of the population surveyed (Gorini et al. 2014).
China has been experiencing exceptionally high levels of air pollution in recent years. A few metropolitan areas are among the most polluted in the world, with daily levels of PM10 averaged at 144.6 μg/m[3] during 2004–2008 in Beijing (Guo et al. 2013) and 216–293 μg/m[3] in autumn in Shanghai (Zhou et al. 2012). Annual levels of PM10 have exceeded 100 μg/m[3] in approximately one-third of the cities covered by the China National Ambient Air Quality Surveillance Network (Yang et al. 2011). PM10 is the only inhalable particulate matter that had been continuously monitored before 2012 within major cities in China. In Fuzhou, the capital city of Fujian Province, daily ambient PM10 levels vary between ∼60–80 μg/m[3]. These values may represent average levels...