3.3 Relationship between air pollutant exposure in early life and the risk of childhood eczema
Pollutant concentrations were divided according to quartiles and binary logistic regression analysis was performed (Table 4). In the single pollutant model, the results showed that increased O3concentrations during pregnancy were a risk factor for cumulative eczema [1.12(1.06-1.19)], one-year-old eczema [1.10(1.04-1.17)], and two-year-old eczema [1.15(1.02-1.29)]. In the multi-pollutant model, PM2.5, PM2.5-10 and PM10with VIF values >5 were considered to have multicollinearity and were not included in the model at the same time, and after adjusting for other pollutants and six variables that were statistically significant in the univariate analysis: parental allergy, work during pregnancy, monthly household income, maternal primipara, frequent window opening and air purifier use, PM10exposure during pregnancy had a significant effect on cumulative eczema [1.27(1.14-1.41)], 1-year old eczema [1.22(1.09-1.36)], and 2-year-old eczema [1.30(1.04-1.62)]. Dividing PM10into PM2.5 and PM2.5-10, PM2.5-10 remained positively associated with the risk of cumulative eczema [1.31(1.20-1.43)], 1-year old eczema [1.31(1.19-1.44)], and 2-year-old eczema [1.20(1.01-1.44)], while PM2.5 had no significant effect.
Table 4 OR and 95% CI of air pollutant exposure during pregnancy for eczema risk in the binary logistic regression model.