IMPROVING INDOOR AIR IN NEW ZEALAND HOMES: THE RESPIRATORY HEALTH EFFECTS OF NITROGEN DIOXIDE EXPOSURE

Many homes in New Zealand are poorly constructed and maintained for the climate with inadequateheating resulting in winter temperatures that frequently fall below the World Health Organisationrecommended level of 18C. Approximately 30% of New Zealand homes are heated by unfluedportable gas heaters. To investigate the link between the indoor air environment and respiratory healtheffects in children, we studied 409 households that used unflued gas heaters or electric heating andhad an asthmatic child. The study explores differences in childrens respiratory health before and aftertheir home received a new form of heating and insulation if required. In 2006, houses were randomlyassigned to the intervention or control group; those in the intervention group (n=195) receivedimproved heating systems prior to the 2006 winter. NO2 and temperature measures were taken ineach of the homes along with objective and subjective health measures. NO2 was significantly relatedto an increase in wheezing, coughing, reliever use, and lower respiratory symptoms, and a decreasein FEV1 readings.