Association of short-term exposure to source-specific PM2.5 with the cardiovascular response during pregnancy in the Shanghai MCPC study

Abstract

Fine particulate matter (PM2.5) has been reported to be associated with the risk of cardiovascular diseases in pregnancy, but few studies have investigated its association with physiological changes in the cardiovascular system; furthermore, the possible effects of source-specific PM2.5 have not been explored. 176 pregnant women were enrolled from the Shanghai Maternal-Child Pairs Cohort (MCPC) in this study to assess the associations between source-specific PM2.5 and changes in the cardiovascular system. Personal PM2.5 exposure measurements and echocardiography examinations were carried out during two follow-up visits (second trimester: 17.3 ± 1.6 weeks and third trimester: 32.3 ± 2.2 weeks) from February 2017 to September 2018. Various chemical components in PM2.5 samples were then determined, including elements, ions, and organic/elemental carbon. Positive matrix factorization (PMF) was used for source apportionment of PM2.5, and linear mixed-effects models were developed to estimate associations between source-specific PM2.5 and the cardiovascular response. Nine pollution factors were identified, namely, secondary sulfate/nitrate, secondary organic carbon (SOC), coal combustion, motor vehicle emissions, residual oil combustion, cosmetics, sea salt, dust and industry emissions. An interquartile range (IQR) increase in residual oil combustion was associated with decreases in cardiac output [−5.25% (95% confidence interval (CI): −9.60, −0.69)] and cardiac index [−5.13% (95% CI: −9.38, −0.70)]. An IQR increase in dust was associated with decreased left ventricular ejection fraction [−0.65% (95% CI: −1.17, −0.11)] and left ventricular fractional shortening [−0.97% (95% CI: −1.69, −0.21)]. In addition, the total PM2.5 mass, cosmetics, and secondary pollution factors (secondary sulfate/nitrate and SOC) were also associated with changes in cardiac structure. The results indicated that short-term exposure to PM2.5 from residual oil combustion and dust appeared to be potential risk factors for decreased left ventricular systolic function in pregnant women. Further research is needed to confirm these preliminary findings.