RESUMEN
Background: Indoor air pollution could play an important role in the susceptibility to respiratory diseases of vulnerable individuals, such as elders and infants. Aim: To evaluate indoor air pollution in a low income population of South East Santiago. Subjects and methods: A domiciliary survey of contaminant sources was carried out in the houses of a cohort of 522 children less than one year old. Using a case-control design, 121 children consulting for respiratory diseases were considered as cases and 131 healthy infants of the same age and sex were considered as controls. In the houses of both groups, active monitors for particulate matter (PM10) and passive monitors for NO2 were installed. Results: Forty two percent of fathers and 30 percent of mothers were smokers, and in two thirds of the families there was at least one smoker. Eighty five percent used portable heaters in winter. Of these, 77 percent used kerosene as fuel. Only 27 percent had water heating appliances. The rest heated water on the kitchen stove or on bonfires. Most kitchen stoves used liquid gas as fuel. Twenty four hour PM10 was 109 ñ 3.2 µg/m3. Mean indoor and outdoor NO2 in 24 h was 108 ñ 76.3 and 84 ñ 53.6 µg/m3 respectively. Indoor NO2 levels were related to the use of heating devices and smoking. No differences in PM10 and NO2 levels were observed between cases and controls. Conclusions: There is a clear relationship between indoor pollution and contaminating sources. Indoor NO2 levels are higher than outdoors