Passive Sampling of Ambient, Gaseous Air Pollutants: A Review

摘要

During the past two decades there has been an increase in the interest to use passive air pollutant sampling systems both indoors and outdoors, particularly in the context of human health risk assessment. Currently such efforts are being directed to ecological response assessments also. Excluding the laboratory analysis costs, passive samplers are inexpensive, easy to use and do not require electricity to operate. Therefore, they are very attractive for use in regional scale air quality assessments. passive samplers allow the quantification of cumulative air pollutant exposures, as total or average pollutant concentrations over a sampling duration. Such systems function either by chemical absorption or by physical adsorption of the gaseous pollutant of interest on to the sampling medium. Selection of a passive sampler must be based on its known or tested characteristics of specificity and linearity of response to the chemical being collected. In addition, the effects of wind velocity, radiation, temperature and realtive humidity must be addressed. Because of all these considerations, passive samplers frequently under or overestimate the cumulative exposures, compared to the corresponding data from co-located continuous monitors or active samplers, although such statistical variance can be minimized by taking needed precautions.