IntroductionUrinary bladder cancer is one of the most frequent occupational tumours, and it can be caused by exposure to several carcinogenic agents 1) .During the early Nineties, it was estimated that up to 24% of bladder cancer in males and about 11% in females were caused by occupational exposure [2][3][4] . Recent analysis have estimated that in Europe about 5-10% of bladder cancers in men and 8% in women could be attributed to occupational exposure 5,6) . Moreover, it has been estimated that about 23% of the European workforce is exposed to occupational carcinogens 7) . The occupations more at risk of exposure to bladder cancer hazards have been identified, in Western Europe, with activities like salt mining, manufacture of carpets, paints, plastics and industrial chemicals, as well as coal gasification, iron and steel founding, aluminium, rubber, magenta and auramine production, shoe and leather manufacture 5) . The most common occupational carcinogens for the bladder are: aromatic amines, polycyclic aromatic hydrocarbons (PAHs), chlorinated solvents, benzene, tar or pitch, and diesel engine exhaust 8) . However, some published studies show uncertainty about jobs and carcinogens involved in occupational bladder cancer risk.Our aim is to estimate the number of blue-collar workers potentially exposed to carcinogens associated with bladder cancer risk in industrial sectors in Italy. We focus on the current relationship between occupations and risk exposures, and our estimate is based on the ISPESL database of Italian enterprises.
Methods and ResultsTo estimate the number of workers potentially exposed, we selected the codes of economic activity (according to the NACE Rev. 1.1 European classification) for which were found statistically significant excess risks of bladder cancer in two recent analyses of pooled data, one for men 5) and the other for women 6) . Since the industrial sectors in these analyses were coded using the ISIC (International Standard Industrial Classification) classification (revision 2), a translation was required. Among