title: Prostate cancer and industrial pollution Risk around putative focus in a multi-source scenario.
abstract: BACKGROUND
  Prostate cancer is the second most common type of cancer among men but its aetiology is still largely unknown. Different studies have proposed several risk factors such as ethnic origin, age, genetic factors, hormonal factors, diet and insulin-like growth factor, but the spatial distribution of the disease suggests that other environmental factors are involved. This paper studies the spatial distribution of prostate cancer mortality in an industrialized area using distances from each of a number of industrial facilities as indirect measures of exposure to industrial pollution.
  
  
  METHODS
  We studied the Gran Bilbao area (Spain) with a population of 791,519 inhabitants distributed in 657 census tracts. There were 20 industrial facilities within the area, 8 of them in the central axis of the region. We analysed prostate cancer mortality during the period 1996-2003. There were 883 deaths giving a crude rate of 14 per 100,000 inhabitants. We extended the standard Poisson regression model by the inclusion of a multiplicative non-linear function to model the effect of distance from an industrial facility. The function's shape combined an elevated risk close to the source with a neutral effect at large distance. We also included socio-demographic covariates in the model to control potential confounding.
  
  
  RESULTS
  We aggregated the industrial facilities by sector: metal, mineral, chemical and other activities. Results relating to metal industries showed a significantly elevated risk by a factor of approximately 1.4 in the immediate vicinity, decaying with distance to a value of 1.08 at 12km. The remaining sectors did not show a statistically significant excess of risk at the source.
  
  
  CONCLUSIONS
  Notwithstanding the limitations of this kind of study, we found evidence of association between the spatial distribution of prostate cancer mortality aggregated by census tracts and proximity to metal industrial facilities located within the area, after adjusting for socio-demographic characteristics at municipality level.
authors.affiliation: Department of Environmental Epidemiology and Cancer, National Centre for Epidemiology, Carlos III Institute of Health, Madrid, Spain. rramis@isciii.es
authors.forename: Rebeca
authors.initials: R
authors.lastname: Ramis
authors.forename: Peter
authors.initials: P
authors.lastname: Diggle
authors.forename: Koldo
authors.initials: K
authors.lastname: Cambra
authors.forename: Gonzalo
authors.initials: G
authors.lastname: López-Abente
mesh_terms: D004781:Environmental Exposure / Q000706:statistics & numerical data; D004787:Environmental Pollution / Q000706:statistics & numerical data*; D006801:Humans; D007220:Industrial Waste / Q000706:statistics & numerical data*; D007221:Industry / Q000706:statistics & numerical data*; D008297:Male; D008954:Models, Biological; D011471:Prostatic Neoplasms / Q000401:mortality*; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology
chemical_list: D007220:Industrial Waste