Increased risk of bladder cancer in critical areas at high pressure of pollution of the Campania region in Italy: A systematic review

During the past three decades, large areas of the Naples and the Caserta provinces of the Campania region in Italy have been extensively contaminated by the widespread burial and open-air dumping and incineration of industrial toxic waste.On the basis of the finding that the incidence of bladder cancer appears remarkably high in the Naples province with respect to the rest of Europe and of a potential causative role of environmental contaminants, we sought associations between exposure to toxic agents and increased mortality/incidence of bladder cancer by performing a systematic search of epidemiology and human biomonitoring studies conducted in the provinces of Naples and Caserta.The data show that the incidence of bladder cancer is higher than expected on the basis of regional data in the province of Naples and in certain areas of the province of Caserta, even after accounting for social deprivation, with two clusters of increased mortality rate located in the north-western part of Naples province and in the south-eastern part of the Caserta province.The biomonitoring studies conducted focused on the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs), which are generated by the uncontrolled combustion of refuse abandoned in the territory and have been shown to enter the food chain. While the average values of PCDD/F and PCBs reported in blood serum and human milk of the area population are in accordance with those expected on the basis of studies conducted at a national and international level, five municipalities assessed in the province of Naples, that is Brusciano, Caivano, Giugliano, Mugnano, and Qualiano–Villaricca were clearly characterized by the presence of arsenic, with 62% samples showing serum arsenic levels higher than the 95th percentile of the national distribution. The potential negative synergism of social deprivation, environmental pressure and arsenic contamination may account for the higher than expected bladder cancer incidence and mortality in certain areas of the Campania region and remains to be elucidated via the conduction of ad hoc population-based studies.