Winning Entry of the Green Estate Photo Competition with Yue Tin Court in the background.
	Air Emissions & Air Quality Pollutants in exhaust emissions from generators in our housing blocks may affect residents' health, whereas odours (especially from restaurants) could cause nuisance. In designing new housing blocks and commercial centres we take considerable care to ensure that emission sources are located correctly and that dispersion of pollutants and odours is good. For instance: The chimney for the emergency generator in each block is positioned so that emissions are dispersed away from living areas; no complaints have been received in the past year. New domestic blocks have their generators installed on the roof top of buildings instead of on the ground floors. Our car parks are designed to prevent accumulation of harmful air pollutants, according to a design guideline prepared in 1997. We have reviewed the existing design of exhaust systems for restaurants and fast food shops to avoid nuisance to nearby domestic tenants, and have issued design guidance. Further activities we have planned are: We intend to study the indoor air quality performance of some existing commercial centres.The results will be used to improve the design of new commercial centres. Ozone Depleting Chemicals We have completely replaced halogen gas fire extinguishers with carbon dioxide or dry powder extinguishers. In addition, we no longer use air conditioning units whose thermal insulation involves ozone depleting chlorofluorocarbon (CFC) during its manufacturing. Furthermore, we have stopped using CFC refrigerant in chillers. Only two chillers containing CFC remain. Work to retrofit them with ozone friendly refrigerant is now in progress and will be finished in the coming year. Also, we are conducting research in the market so that we can adopt CFC and hydrochlorofluorocarbon (HCFC)-free thermal roof insulation materials. We expect to specify these alternative materials in tenders from December 2001. Measuring in-door radon levels in public housing estates. Radon Radon gas is a potential health hazard given that the geology of Hong Kong is predominately granite - the typical type of rock emitting the gas. In 1994, a consultancy study was undertaken in collaboration with the Environmental Protection Department to measure the indoor radon levels in 48 public housing estates. The study found that the level of radon present in most housing estates was low and concluded that this gas did not constitute a health hazard to residents. To ensure there are no on-going problems, another radon survey was carried out in 1998 and the conclusions were similar. In 2000, we conducted another survey on 100 flats in 25 estates. This time we also investigated if there are any links between factors such as level of furnishings in flats and radon levels. Our results show no rising trend in radon levels since previous years. Radon levels in all occupied flats were within the safe limits. In uninhabited vacant flats, radon levels were higher due to prolonged lack of ventilation. For this reason, we recommended good ventilation of flats as good practice for air circulation. < Previous PageNext Page >Back to Top 2001 Housing Authority. All rights reserved.