3.4 Identification of critical windows for
PM2.5-10 and O3 exposure to childhood
eczema
In the DLM with eczema at 2 years of age as an outcome, the exposure
period was the entire life course before the date of eczema onset at 2
years of age. Finding the sensitive window during pregnancy and after
birth separately through DLM. PM10,
PM2.5-10 and O3 exposure was divided by
weeks. There was no significant sensitivity window for
PM10 and PM2.5-10 exposure during
pregnancy, but 0-23 weeks postnatal for PM10 and 3-13
weeks postnatal for PM2.5-10 were critical risk windows
for eczema at 2 years of age. O3 exposure at 32-42 weeks
of pregnancy, 0-10 weeks and 91-105 weeks postnatal were critical risk
windows (Figure 3).