Environmental exposure to airborne asbestos fibres in a highly urbanized city.

Asbestos fibres, when released into the air, can pose serious health hazards to exposed people. The aim of this study was to determine the concentration of respirable asbestos fibres in a highly urbanized and densely populated town, where asbestos-containing materials have been widely used in building constructions. Their presence and degree of corrosion were the main criterion for location of sampling stations. All air samples were collected applying the recently elaborated sampling strategy. The origin of sampled fibres was additionally proved by SEM analysis. Concentrations of respirable fibres, derived from 2 groups of asbestos minerals (crocidolite and chrysotile) varied from 0.0010-0.0090 f/cm(3). The highest concentrations were observed in the immediate vicinity of the buildings where a large accumulation of damaged asbestos-containing materials was found, compared to sites located from 100-500 m from such buildings, or treated as a "free" from asbestos sources. It was revealed that even a relatively gentle air movement (1 m/s) plays an important role in the spreading of fibres near the asbestos source. The data of spatial distribution of respirable asbestos fibres in the form of a map can be a useful tool for the official bodies to plan necessary asbestos remediation actions.