Personal and indoor/outdoor nitrogen dioxide exposure assessments of 23 homes in Taiwan.

Indoor and outdoor nitrogen dioxide (NO2) concentrations of 23 homes from two areas in Taiwan, the city of Taipei and a rural village in central Taiwan, were measured concurrently from December 1987 to January 1988. NO2 measurements were carried out by Palmes tube for one week and filter badges for two days. In Taipei, the mean NO2 concentrations outdoors, in the kitchens, in the livingrooms, and in the bedrooms were 40.1 ppb, 34.4 ppb, 32.1 ppb, and 29.7 ppb for one week, and were 25.7 ppb, 25.6 ppb, 22.6 ppb, and 20.5 ppb for two days. In the village of central Taiwan, the corresponding concentrations were 23.5 ppb, 24.5 ppb, 20.4 ppb, and 17.5 ppb for one week, and 20.3 ppb, 24.7 ppb, 18.8 ppb, and 15.4 ppb for two days. The NO2 concentrations of all microenvironments in Taipei were significantly higher than those in the village of central Taiwan. The outdoor NO2 concentrations were significantly higher than the indoor NO2 concentrations in Taipei. The NO2 measurements in the kitchens were higher than all other measurements indoors and outdoors in the village of central Taiwan. The houses which used natural gas as cooking fuel had slightly higher indoor NO2 concentrations than the houses which used LPG as cooking fuel in Taipei city. Cement houses had slightly higher indoor NO2 concentrations than brick houses. The mean of housewives' exposures was 30.8 ppb in Taipei and 19.9 ppb in the village of central Taiwan. The explanation power of the housewife's exposure to NO2 was 72% by the time weighted-average model and 70% by the simple linear regression model.