Preliminary incidence analysis in skin basalioma patients exposed to arsenic in environmental and occupational settings

The subject of our analysis was a database of 404 skin basalioma cases collected within 15 years (3 five-year intervals) in a region polluted by emissions from the burning of coal with high arsenic content ranging between 900 and 1,500 g per metric ton of dry coal. The standardized incidence of skin basaliomas (each confirmed histologically) in a district with a population of similar to 125,000 in non-occupational settings ranged from 39.66 to 39.88 per 100,000 (study base 961,960 man/year) while relevant data for occupational settings (male workers of a power-plant burning arsenic-rich coal! ranged from 175.44 to 493.31 per 100,000 (study base 21,360 man/year). Exposure assessment was based on biological monitoring. Determination of arsenic was done in groups of 10-year-old boys tin non-occupational settings) by analyzing hair and urine samples at different localities situated up to a distance of 30 km from the local power-plant. The results obtained seemed to suggest that arsenic is probably a promoter rather than a true carcinogen-at least in connection with arsenic-exposure-related skin basalioma incidence. The non-threshold concept of arsenic carcinogenicity seems not to be supported by the results of our database analysis.