Indoor air pollution levels from stoves in some kitchens are higher than outdoor levels even in some urban-center hotspots, according to a new study by British scientists.
Researchers from the University of Sheffield's Faculty of Engineering who measured air quality inside and outside three residential buildings found nitrogen dioxide (NO2) levels in the kitchens of some city apartments with gas stoves were three times higher than the concentrations measured outside.
The findings, published online in the Journal of Indoor and Built Environment, suggest many homes may have higher levels of indoor pollution than those typically found even in urban outdoor environments.
"We spend 90 percent of our time indoors and work hard to make our homes warm, secure and comfortable, but we rarely think about the pollution we might be breathing in," said lead researcher Vida Sharifi. "Energy is just one source of indoor pollution, but it is a significant one. And as we make our homes more airtight to reduce heating costs, we are likely to be exposed to higher levels of indoor pollution, with potential impacts on our health."
The study, funded by the Engineering and Physical Sciences Research Council, compared a rural house with two apartments, one in central Sheffield and the other in an urban location next to a busy road. The rural house had an electric stove while both flats used gas appliances. Samples were taken outside and inside the properties, from each kitchen, over a four-week period.
The average pollution concentrations in the kitchens of both apartments were higher than the levels set by the government for outdoor air quality. There are currently no set guidelines for safe levels of pollution in the home.
"Concerns about air quality tend to focus on what we breathe in outdoors, but as we spend most of our time indoors, we need to understand more about air pollution in our homes,” said Sharifi. “There is very little data on emission rates from different appliances or acceptable standards on indoor pollutants.”