Indoor Air Quality of Institutional Buildings and Residential Houses in Yokohama

Abstract

Indoor air quality is a significant concern, because when the hours spent sleeping, working in offices or at school are added up, people on average spend the vast majority of their time indoors where they are repeatedly exposed to indoor air pollutants. In this study, gaseous chemical compounds in institutional and residential buildings were measured in order to evaluate chemical exposure to office worker. Gaseous chemical compounds were measured in indoor and outdoor air of 18 institutional buildings and 77 residential houses throughout Yokohama in winter and summer. Four kinds of diffusive samplers were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenylhydrazine and trans-1,2-bis (2-pyridyl) ethylene coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid impregnated silica for basic gases. As results of this study, there were no institutional buildings exceeding Ministry of Health, Labour and Welfare, Japan (MHLW) guidelines in winter and summer. However, in residential houses, 19% houses in summer and 15% houses in winter exceeded guidelines by MHLW. Total gaseous chemical compounds of institutional buildings is about half of residential houses in both summer and winter. Almost all compounds in residential indoor air were present at higher levels in summer than in winter. However, the nitrogen dioxide concentrations in residential indoor air particularly increased only during winter and was well correlated with the formic acid concentration (correlation coefficient=0.958).