People who suffer from airborne respiratory allergies often advised to obtain and rely upon portable HEPA filtered air devices for relief. While this advice may work for some individuals, many allergic people do not experience relief or a lessening of symptoms. For allergic individuals for whom this mitigation strategy is not successful, the manufacturers' claims seem over stated.

The UK Building Research Establishment has carried out measurements of levels of nitrogen dioxide (N02) in 12 homes in the South of England. Two types of detection device were used: the Scintrex LMA-3 continuous N02 analyser and the Palmes passive diffusion tube. NO 2 concentrations were recorded using both devices in the kitchen, living room and a bedroom of each home for a period of a week. Gas cooking was observed to be the most important source of peak concentrations of N02 in the home.

Domestic gas apparatus generate oxides of nitrogen (NOx), which have been classed in recent years as problem products in the context of indoor air quality (IAQ). These, together with carbon monoxide which may also be present in the products of gas combustion, mean that the formulation of regulations for health protection presents complex problems. The present work shows the importance of this matter and presents interesting case studies taken from the Basque Country and our area of influence. It also makes specific recommendations as to how existing regulations should be changed.