Global, regional, and national burden of preterm birth attributable to ambient and household PM2.5 from 1990 to 2019: Worsening or improving?

ABSTRACT

BACKGROUND: Maternal exposure to fine particular matter (PM2.5) during pregnancy, including ambient and household PM2.5, has been linked with increased risk of preterm birth (PTB). However, the global spatio-temporal distribution of PTB-related deaths and disability-adjusted life years (DALYs) attributable to PM2.5 is not well documented. We estimated the global, regional, and national patterns and trends of PTB burden attributable to both ambient and household PM2.5 from 1990 to 2019. METHODS: Based on the Global Burden of Disease Study (GBD) 2019 database, we obtained the numbers of deaths and DALYs as well as age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) of PTB attributable to total, ambient, and household PM2.5 by socio-demographic index (SDI) and sex during 1990-2019. The average annual percentage changes (AAPCs) were calculated to assess the temporal trends of attributable burdens. RESULTS: In 2019, 126,752 deaths and 11.3 million DALYs related to PTB worldwide (two-thirds in Western Sub-Saharan Africa and South Asia) could be caused by excess PM2.5 above the theoretical minimum-risk exposure level (TMREL), of which 39 % and 61 % were attributable to ambient PM2.5 and household PM2.5, respectively. From 1990 to 2019, the global ASMR due to ambient PM2.5 increased slightly by 7.08 % whereas that due to household PM2.5 decreased substantially by 58.81 %, although the latter still dominated the attributable PTB burden, especially in low and low-middle SDI regions. Similar results were also observed for ASDRs. In addition, PTB burden due to PM2.5 was higher in male infants and in lower SDI regions. CONCLUSIONS: Globally in 2019, PM2.5 remains a great concern on the PTB burden, especially in Western Sub-Saharan Africa and South Asia. Between 1990 and 2019, age-standardized burden of PTB due to ambient PM2.5 increased globally, while that due to household PM2.5 decreased markedly but still dominated in low and low-middle SDI regions.