Fig. 3
Effects of combined exposure of climate factors and NO2 on respiratory disease risk in infants aged six months during the first trimester of pregnancy. (A) Stratified analysis by temperature, with tertile 1 defined as < 9.7 °C, tertile 2 as 9.7–17.1 °C, and tertile 3 as > 17.1 °C. (B) Stratified analysis by humidity, where tertile 1 is < 60.8%, tertile 2 is 60.8–69.0%, and tertile 3 is > 69.0%. The straight line with a circle mark indicates NO2 < 19.4 ppb, the triangle mark indicates 19.4–23.5 ppb, and the square mark indicates > 23.5 ppb. The Y-axis depicts 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 NO2 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.
