Indoor Nitrogen Dioxide Exposure and Children’s Pulmonary Function

Elevated concentrations of nitrogen dioxide (NO₂) are produced in the home by the use of unvented gas appliances. In studies on potential health effects of Indoor exposure to NO₂, exposure has mostly been estimated from the presence or absence of sources like gas cookers in the home. This leads to misclassification of exposure, as NO₂ concentrations in the home depend also on source use, ventilation habits, time budgets, etc. The availability of cheap, passive monitoring devices has made it possible to measure Indoor concentrations of NO₂ directly in health effects studies, albeit with averaging times of one to several days. So far, it has not been evaluated whether this increases the sensitivity of a study to detect health effects of NO₂. In this paper, a comparison is made between NO₂ sources and weekly average indoor NO₂ measurements, as predictors of pulmonary function in a study among children aged 6–12 years.

The relationship between exposure and lung functions was found to be generally non-significant in this study. The results further suggested that in this study, measuring Indoor NO₂ concentrations with passive monitors offered no advantage over the simple use of source presence as exposure variable.     

Indoor NO2 pollution and personal exposure to NO2 in two areas with different outdoor NO2 pollution

Indoor NO₂ concentrations were measured in the kitchen, the living room and bedroom of 612 houses in two different areas in the Netherlands. In a group of housewives living in these homes, personal exposure to NO₂ was measured. NO₂ concentrations indoors were dependent on the presence or absence of (un)vented gas appliances. Personal NO₂ exposure was only different between the two areas in the group with the lowest indoor concentrations. In this study, it was determined that gas appliances inside the house are the most important factor with respect to NO₂ exposure and that outside NO₂ concentration played a secondary role, except in situations where gas appliances were absent.     

Indoor carbon monoxide pollution in The Netherlands

Most houses in the Netherlands are equipped with gas-fired heaters and cooking appliances,since large amounts of natural gas are available within the country since the mid-1960's. Carbon monoxide poisoning due to coal fires has virtually ceased to exist when coal-fired heaters were replaced by gas heaters. However, such poisonings still occur, although to a lesser extent, due to the use of instantaneous water heaters (geisers) that are gas fired. An investigation was carried out to establish the CO production potential of geisers under normal conditions of use. The study involved 254 houses; the results indicated that 17% of the geisers produced a CO level of more than 50 μL/L in the kitchens where they were located, after 15 min of operation. Presence of a flue, burner type, and maintenance system proved to be the main controlling factors.     

Indoor nitrogen dioxide exposure and children's pulmonary function

Elevated concentrations of nitrogen dioxide (NO2) are produced in the home by the use of unvented gas appliances. In studies on potential health effects of indoor exposure to NO2, exposure has mostly been estimated from the presence or absence of sources like gas cookers in the home. This leads to misclassification of exposure, as NO2 concentrations in the home depend also on source use, ventilation habits, time budgets, etc. The availability of cheap, passive monitoring devices has made it possible to measure indoor concentrations of NO2 directly in health effects studies, albeit with averaging times of one to several days. So far, it has not been evaluated whether this increases the sensitivity of a study to detect health effects of NO2. In this paper, a comparison is made between NO2 sources and weekly average indoor NO2 measurements, as predictors of pulmonary function in a study among children aged 6-12 years. The relationship between exposure and lung functions was found to be generally non-significant in this study. The results further suggested that in this study, measuring indoor NO2 concentrations with passive monitors offered no advantage over the simple use of source presence as exposure variable.