Exposure of Primary School Children and their Mothers to Nitrogen Dioxide in Sapporo City: Comparisons of groups clustered by maternal daily behavior and habits.

Abstract

Exposure of primary school children and their mothers to No₂ was investigated in two schools in the city of Sapporo. One school was located in the city center and another in a suburb of the city. The school children and mothers were requested to put on NO₂ filter badges for 24 hours and to record activity during that period. They were also requested to fill out ATS-DLD questionnaires. The surveys were repeated twice, in the summer of 1986 and in the winter 1987, due to possible seasonal variation.
Average NO₂ exposure levels of both school children and mothers were lower in the summer than the corresponding averages in the winter. The average of the children was lower than that of mothers in both summer and winter. Averages of the children of the city-center school were higher than those of children in the school in the suburb in both summer and winter. These differences were not observed in mothers' averages. To examine the relationship between NO₂ exposure levels and maternal daily behavior and habits, the subjects were classified into three clusters by employment status, living area, smoking habits, type of heating appliance, and use of fans during cooking. While average NO₂ exposure levels of children were similar among the three clusters, the average of the mothers of the third cluster was the highest among the clusters in either summer or winter. The third cluster was characterized by the highest rate of employment among the clusters, spending less time in their kitchens and not using fans regularly.
These observations indicated that factors associated with NO₂ exposure were different between children and mothers and that mothers engaged in occupations were at higher risk of NO₂ exposure.