Emission of Nitrogen Dioxide from Butane Gas Heaters and Stoves Indoors

Levels of indoor nitrogen dioxide (NO₂) in a home equipped with butane gas stove and heaters are reported between the months of February and July 2003. Diffusion passive sampling was used for the simultaneous measurements of indoor and outdoor NO₂ concentrations. The overall average indoor NO₂ concentrations were 15.6 and 22.3 μg m^-3 for the living room and kitchen, respectively, while that for outdoors was 17.9 μg m^-3. In order to assess the input of indoor combustion to exchanged outdoor levels of NO₂, the ratios of the living room and kitchen NO₂ values to their corresponding outdoor levels were found to be higher in winter than in spring and summer. An I/O ratio as high as 2.1 detected in winter was attributed to the excess use of butane gas heaters in both the kitchen and the living room. Other sources and fates of indoor NO₂ are also evaluated. This study will have significant effects on estimating health risks related to the used of butane gas heaters in residential homes.