Home environmental characteristics of participating parents (n = 4530).

aSubject's home located within a distance of 200 meters of a main road or highway.
bSubject's home has been redecorated/renovated since 1 year before pregnancy.
cSubject's home has acquired new furniture since 1 year before pregnancy.
dSubject has reported any of the four dampness signs at home: mold spots, damp stains, water damage or window pane condensation during winter in child's bedroom.
eSubject has seen cockroaches/rats/mosquitoes/flies in home.
fSubject has used mosquito-repellent incense/incense in home.
*p<0.05;
**p<0.01;
***p<0.001.