GROUNDWATER ASBESTOS POLLUTION FROM NATURALLY OCCURRING ASBESTOS (NOA): A PRELIMINARY STUDY ON THE LANZO VALLEYS AND BALANGERO PLAIN AREA, NW ITALY.

Groundwater or surface water flow into natural rock formations containing asbestos (NOA), e.g. serpentinites and metabasites, may result in water asbestos pollution. In fact, asbestos-bearing rocks weathering is the principal natural cause of fibres water-dispersion. As asbestos constitute a risk to human health, it is crucial, into NOA contexts, to verify the occurrence of mineral fibres in water resources, given their importance for agricultural and industrial activities and as a primary source for drinking water. For this purpose, the Lanzo Valleys and Balangero Plain (NW Italy) were selected as study area where to evaluate the possible occurrence of asbestos in groundwater, to correlate it to the geolithological and hydrogeological characteristics of the context and therefore to evaluate the possible mobility of asbestos in aquifers. The results of this preliminary study show the presence of asbestos in groundwater, generally occurring in very thin fibres which require TEM-EDS analysis. Water chemical characters, particularly dissolved cations, reflect the lithologies which occur in the area; concerning trace metals, only Ni shows a relation with NOA occurrence. In addition, several problems on sampling and analysis procedures are highlighted and discussed. [ABSTRACT FROM AUTHOR]