CARCINOGENS IN THE INDOOR AIR OF HONG-KONG HOMES - LEVELS, SOURCES, AND VENTILATION EFFECTS ON 7 POLYNUCLEAR AROMATIC-HYDROCARBONS

The concentration of carcinogens in the airborne dust of 33 homes in H ong Kong was studied to identify the sources and measure the amounts o f 7 polynuclear aromatic hydrocarbons (PAH) including benzo(a)pyrene. The 24 hr samples were collected from kitchens and living rooms of wor king class homes and analyzed by HPLC. The mean levels of PAH in air a nd dust were comparatively low, with cooking fires and incense associa ted with significant increases, and window ventilating fans with signi ficant decreases in PAH concentrations. Perceived pollution sources li ke water heaters, cigarette smoke, and stir-fry cooking, led to reduce d airborne PAH levels because human responses to these emission source s were to increase natural and mechanical ventilation. The data indica ted that compensation behaviours can over-ride the effects of emission sources, and help explain why measures of increased ventilation from open windows and doors were generally associated with higher PAH level s. The results of this study show that indoor air quality in homes var ies with cultural practices, behavioural responses, and climate.