Residential exposure to overhead high-voltage lines and the risk of testicular cancer: results of a population-based case–control study in Hamburg (Germany)
Background: In a population-based case–control study we examined the association between residential exposure to overhead high-voltage lines and testicular cancer. Methods: We recorded the residential biography of cases with testicular cancer identified by the Hamburg Cancer Registry and of controls that were randomly selected from the mandatory registry of residents in Hamburg. The study included 145 incident cases between 15 and 69 years of age, diagnosed between 1995 and 1997, and 313 controls, matched for age in 5-year strata. In model A, exposure was defined by distance (ever vs never). Model B took into account residence time and the inverse distance from the nearest high-voltage line. It distinguished between low and high exposure, the never exposed persons serving as a reference group. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated by unconditional logistic regression. For men below the age of 40 years and men aged 40 years and over separate analyses were carried out. Results: Within a corridor of 100 m the prevalence of exposure to high-voltage lines in Hamburg was 6.9% in cases and 5.8% in controls (OR=1.3, 95% CI=0.56–2.80). In the more complex model B we found an OR of 1.2 (95% CI=0.60–2.47) for low exposure and 1.7 (95% CI=0.91–3.32) for high exposure. Younger men show slightly increased risks in both models. Conclusions: In all, residential exposure to high-voltage lines did not seem to be a major risk factor for testicular cancer in our study. Yet, the fact that risks for men below the age of 40 years were slightly increased in both exposure models deserves further attention.