Insufficiency of natural ventilation against NOx concentrations caused by domestic gas cookers.

Spanish regulations, like those of other countries, lay down various criteria for the permanent ventilation opening which must exist in premises containing gaspowered domestic food cookers. There is growing concern as to the effects of NOx on the health of weaker people such as children old people and those suffering from respiratory ailments, who spend most time at home. The paper shows the results obtained and the solutions proposed in our investigation of more than 70 dwellings in the Basque Country, Cantabria and Burgos in northern Spain, using approved and calibrated measuring devices. The investigation shows that regulations are often breached, and also that peaks of NOx concentration can occur relatively quickly even when the amount of these pollutants emitted by cookers is below the limits approved by renowned research institutions. As might be expected, the problem of dissemination is also present, causing pollutants to be carried into other parts of the home. This shows that ventilation criteria in these cases should be based on C02 levels, as they usually are, but on NOx levels. Independently of the above, in some cases inadmissible CO levels were found (for known reasons) which are not prevented either by the present regulations. The paper also gives some results from dwellings with extractor devices, which have proved inadequate in some cases. The relevant authorities in our area have been informed. Part of this work has been published in specialist journals and reported in lectures to professional associations, with proposals for  solutions to prevent damage to health and adverse economic effects.