title: Childhood cancer and nuclear power plants in Switzerland: a census-based cohort study.
abstract: BACKGROUND
  Previous studies on childhood cancer and nuclear power plants (NPPs) produced conflicting results. We used a cohort approach to examine whether residence near NPPs was associated with leukaemia or any childhood cancer in Switzerland.
  
  
  METHODS
  We computed person-years at risk for children aged 0-15 years born in Switzerland from 1985 to 2009, based on the Swiss censuses 1990 and 2000 and identified cancer cases from the Swiss Childhood Cancer Registry. We geo-coded place of residence at birth and calculated incidence rate ratios (IRRs) with 95% confidence intervals (CIs) comparing the risk of cancer in children born <5 km, 5-10 km and 10-15 km from the nearest NPP with children born >15 km away, using Poisson regression models.
  
  
  RESULTS
  We included 2925 children diagnosed with cancer during 21 117 524 person-years of follow-up; 953 (32.6%) had leukaemia. Eight and 12 children diagnosed with leukaemia at ages 0-4 and 0-15 years, and 18 and 31 children diagnosed with any cancer were born <5 km from a NPP. Compared with children born >15 km away, the IRRs (95% CI) for leukaemia in 0-4 and 0-15 year olds were 1.20 (0.60-2.41) and 1.05 (0.60-1.86), respectively. For any cancer, corresponding IRRs were 0.97 (0.61-1.54) and 0.89 (0.63-1.27). There was no evidence of a dose-response relationship with distance (P > 0.30). Results were similar for residence at diagnosis and at birth, and when adjusted for potential confounders. Results from sensitivity analyses were consistent with main results.
  
  
  CONCLUSIONS
  This nationwide cohort study found little evidence of an association between residence near NPPs and the risk of leukaemia or any childhood cancer.
authors.affiliation: Division of International and Environmental Health, Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland.
authors.forename: Ben D
authors.initials: BD
authors.lastname: Spycher
authors.forename: Martin
authors.initials: M
authors.lastname: Feller
authors.forename: Marcel
authors.initials: M
authors.lastname: Zwahlen
authors.forename: Martin
authors.initials: M
authors.lastname: Röösli
authors.forename: Nicolas X
authors.initials: NX
authors.lastname: von der Weid
authors.forename: Heinz
authors.initials: H
authors.lastname: Hengartner
authors.forename: Matthias
authors.initials: M
authors.lastname: Egger
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Kuehni
mesh_terms: D000293:Adolescent; D000396:Air Pollutants, Radioactive / Q000009:adverse effects*; D019352:Censuses; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007953:Leukemia, Radiation-Induced / Q000453:epidemiology / Q000209:etiology; D008297:Male; D009369:Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D055848:Nuclear Power Plants; D011839:Radiation, Ionizing; D012042:Registries; D012044:Regression Analysis; D012111:Residence Characteristics; D012307:Risk Factors; D013557:Switzerland / Q000453:epidemiology
chemical_list: D000396:Air Pollutants, Radioactive