Global preterm births attributable to BTEX (benzene, toluene, ethylbenzene, and xylene) exposure

Epidemiological studies have shown that long-term exposure to toxic volatile organic compounds, such as benzene, toluene, ethylbenzene, and xylene (BTEX), is associated with preterm births (PTB). However, global PTB attributable to long-term BTEX exposure has not been reported in the literature yet. In this study, we employed a global chemical transport model, GEOS-Chem (Goddard Earth Observing System coupled with chemistry), in conjunction with an epidemiological model, to quantify the global country-specific PTB associated with long-term BTEX exposure at the horizontal resolution of 1 km x 1 km for the year 2015. Model simulated surface annual mean BTEX concentrations in GEOS-Chemhave been thoroughly evaluated against global in-situ observations, which demonstrated that model simulated BTEX concentrations fairly agreed with observations but tended to be underestimated in India. Our study found that the global annual total PTB attributable to BTEXwas 2.01 million [95% confidence interval (95CI): 1.16-2.70 million] in 2015, with largest contributions from India (28.3%), followed by China (27.5%), Pakistan (6.2%), Indonesia (4.2%), Bangladesh (3.7%) and United States (2.3%). The global annual total PTB due to BTEX exposure accounted for 19.6%(95CI: 11.3-26.4%) relative to the global annual total all-cause PTB (10.24 million) in 2015. Our study has significant implications on air pollution mitigation policy associated with country-specific anthropogenic BTEX emission reductions to achieve the benefit of human health.

Automated summary

Epidemiological studies have shown that long-term exposure to toxic volatile organic compounds, known as BTEX, is associated with preterm births. This study used a global chemical transport model and an epidemiological model to quantify the country-specific preterm birth rate attributable to long-term BTEX exposure in 2015. The study found that there were 2.01 million preterm births globally due to BTEX exposure, with the largest contributions from India.