NATURAL RADIOACTIVITY, HARMFUL ELEMENT DISTRIBUTION AND CANCER MORTALITY IN THE CAMPANIA REGION (ITALY)

In the Campania region (southern Italy), studies on the distribution of metallic harmful elements and radioactivity have been carried out, both on stream sediments, at a regional scale, and on soils, at a local scale (urban areas). Lima et al. (Appl. Geochem, 20, 611-625, 2005) demonstrated that high U, Th and K values in stream sediments correspond well with the occurrence of volcanic rocks in the central-western part of the region, whereas low values characterize sedimentary deposits in the rest of the region. Gamma-ray spectrometry maps produced for ⁴⁰K, more useful than ²³⁸U and ²³²Th, show particularly high radioactivity levels which corresponds with all the eruptive centers (Roccamonfina, Campi Flegrei and Somma–Vesuvius, including the fissure sources of Campania Ignimbrites). In these areas, concentrations of harmful elements, such as Pb, Zn, Cd, Cu, etc., are generally above the regional average, as well (Albanese et al., J. Geochem. Expl. in press on-line, 2006).

The atlas of cancer mortality for the Campania residents during the period 1982–2001 shows that especially in the north-western sector of the region, the standardized mortality ratio (SMR) on the overall regional population for all neoplasms, expressed as a percentage, is always above 110 (Pizzuti et al., Reg. Camp. – Oss. Epid. Reg., 119 pp., 2006). These higher risk areas roughly correspond to the zones where radioactivity and harmful element concentrations are higher than the rest of the regional territory, implying that the naturally occurring radioelements and the intense anthropogenic pressure on the environment could be possible causes of increased cancer risk. Since SMR is higher mostly in the provincial area of Naples, where a detailed geochemical soil survey has been carried out (Cicchella et al., Geochem.: Explor., Environ., Analysis 5, 29–40, 2005), further studies are in progress to relate SMR to harmful element distribution in the soils of the area. Knowledge of the epidemiology integrated with a detailed elemental study of soil will be important to assess the risks related to various potential causes.