[Respirable mineral fibers in atmospheric air of Wrocław].

Serpentine asbestos from the Naslawice mine, which contains mineral impurities of the serpentinite group--chrysotile and antigortie, has been used to built school sports grounds as well as roads and playgrounds within residential areas. The study was aimed to measure concentrations of respirable mineral fibres in the atmospheric air at the time children were playing on one of the playgrounds as well as at four other sites of Wroclaw. Air samples were collected using individual dosimeters and distributions of length and concentration of fibres were measured by means of a laser fiber monitor FM7400. X-ray diffraction and infrared spectrometry were used to determine the mineral composition of raw material collected from the playground. Morphology of particles of dust from the atmospheric air was analysed by means of electronic microscopy. It was found that the concentration of mineral fibres in the air in question depended on the number of children playing, namely when 7 children were playing the concentration value was equal to 165 fibres/litre and 549 fibres/litre with the number of 20 children. The concentration of fibres in a flat in the vicinity of the playground covered with serpentinite was about 11 times higher than at a street crossing with heavy traffic of motor vehicles. Antigorite and chrysotile were found in samples of raw material used to cover the playground. Numerous particles of fibrous structure were observed in the electronic microscopy image of air dust samples collected from the playground.