Fig. 2
Effects of combined exposure of climate factors and PM2.5 on respiratory disease risk in infants aged six months during the first trimester of pregnancy. (A) Stratified analysis by temperature, defining tertile 1 as < 9.7 °C, tertile 2 as 9.7–17.1 °C, and tertile 3 as > 17.1 °C. (B) Stratified analysis by humidity, categorizing tertile 1 as < 60.8%, tertile 2 as 60.8–69.0%, and tertile 3 as > 69.0%. The straight line with a circle, triangle, and square marks indicate PM2.5 concentrations < 25.7, 25.7–32.9, and > 32.9 µg/m3, respectively. The Y-axis represents the AOR (95% CI) for the combined exposure effect of climate variables and air pollution on respiratory disease risk. Multiple logistic regression models were used to explore the association between respiratory diseases and combined exposure to PM2.5 and climate factors. The models were adjusted for maternal age, education, income, BMI, gestational age, exposure to secondhand smoke, birth weight, sex, and season of birth.
