Risk of Incidence of Selected Malignancies and Human Exposure to Polyhalogenated Hydrocarbons

Abstract

ISEE-924 Objective: Findings regarding the carcinogenicity of polyhalogenated hydrocarbons are still inconclusive and even contradictory. We analyzed the incidence of selected malignancies in a population exposed to polychlorinated biphenyls (PCBs) by comparing data available in the Czech National Cancer Registry database for Czech Republic (∼10 million inhabitants), with data from the population of Uherské Hradišťe District (∼146,000 inhabitants). The District Uherské Hradišťe (UH) is recognized as the most heavily PCB-contaminated area in Czech Republic. Material and Methods: Cancer incidence data was analyzed for the 10-year period 1987–1996. The age adjusted world standard ratio (WSR), the over all (total) incidence of malignancies, and the incidence of thyroid, pancreatic, breast, ovarian, bladder, brain, prostate, and testicular tumors found in local populations were compared. Statistical significance was evaluated using two sample paired t-tests of the means in the STATISTICA 6.0 software. Results: The only statistically validated difference, between the UH District and the Czech Republic analyzed database, was a lower incidence of bladder malignancies both in men and women on the same level of significance (P < 0.01). This study does not confirm our previous experience from Eastern Slovakia. In a former study, which was respecting the same protocol in a population heavily exposed to PCBs, there was a lower incidence of breast (P < 0.01) and prostate malignancies (P < 0.03), in the local population (∼112,000 inhabitants), compared with the whole Slovakia (∼5 million inhabitants). Conclusions: Neither PCBs nor polychlorinated dibenzofurans (PCDFs) appear to contribute to the observed lower incidence of bladder cancer in men and women (P < 0.01) in the UH District. However, antiestrogenic and antiandrogenic properties have been described for hydroxylated and methylsulfonyl PCBs metabolites. Acknowledgement: This study is a continuation of the recently finished 5th FP PROJECT: Evaluating human health risk from low-dose and long-term PCB exposure QLK4-2000-00488 PCBRISK and currently supported by CASCADE NoE 6FP EC.