3.2 Concentrations of air pollutant exposure in the early life
The exposure to pollutants during pregnancy, 1 year after birth and 2 years after birth of the study subjects was shown in Table 2. Higher levels of pollutant exposure during pregnancy than after birth and higher levels of pollutant exposure in the first year after birth than in the second year after birth (all P -values < 0.001). In Table 3, the pollutant exposure of eczema and non-eczema subjects in different exposure periods was compared. Only pollutant concentrations during pregnancy differed significantly between eczema and non-eczema populations (P <0.001), with only NO2concentrations differing during the other periods. In Figure S1, we showed changes in the concentration of pollutants during pregnancy among subjects at different conception dates. Figure S2 showed the correlation between the pollutants at different exposure periods, with a strong correlation between the pollutants.
Table 2 Exposure concentrations of air pollutants in different stages of early life.