Association of prenatal PM1, PM2.5, and PM10 exposure with early childhood hemoglobin levels and anemia: Identification of susceptibility windows

The effects of exposure to particulate matter (PM) during different gestational periods on childhood anemia remain unexplored. This study included 1235 mother-offspring pairs derived from the pediatric subcohort of the Fujian Birth Cohort Study. Maternal exposure to PM 1 , PM 2.5 , and PM 10 was estimated using the ChinaHighAirPollutants dataset for four periods: the entire pregnancy and each of the three trimesters. We employed linear and logistic regression models to assess the effects of PM exposure on hemoglobin levels and anemia incidence, respectively. Additionally, distributed lag models were performed to detect the sensitive windows. PM exposure was associated with reductions in hemoglobin levels throughout the entire pregnancy, particularly during the first and second trimesters. During the entire pregnancy, each 1 μg/m 3 increment in PM 1 , PM 2.5 , and PM 10 exposure was linked to a decrease in hemoglobin levels of 1.02 (95% CI: −1.52, −0.53), 0.87 (95% CI: −1.28, −0.46), and 0.37 (95% CI: −0.56, −0.19), respectively. Regarding anemia risk, in the first trimester, each unit increase in PM 1 , PM 2.5 , and PM 10 increased the odds of developing anemia with ORs of 1.23, 1.16, and 1.09. DLMs showed that the sensitive window for PM exposure was early-mid pregnancy for hemoglobin levels but was limited to the first trimester for anemia risk.