title: Increase of regional total cancer incidence in north Sweden due to the Chernobyl accident?
abstract: OBJECTIVE
  Is there any epidemiologically visible influence on the cancer incidence after the Chernobyl fallout in Sweden?
  
  
  METHODS
  A cohort study was focused on the fallout of caesium-137 in relation to cancer incidence 1988-1996.
  
  
  METHODS
  In northern Sweden, affected by the Chernobyl accident in 1986, 450 parishes were categorised by caesium-137 deposition: < 3 (reference), 3-29, 30-39, 40-59, 60-79, and 80-120 kiloBecquerel/m(2).
  
  
  METHODS
  All people 0-60 years living in these parishes in 1986 to 1987 were identified and enrolled in a cohort of 1 143 182 persons. In the follow up 22 409 incident cancer cases were retrieved in 1988-1996. A further analysis focused on the secular trend.
  
  
  RESULTS
  Taking age and population density as confounding factors, and lung cancer incidence in 1988-1996 and total cancer incidence in 1986-1987 by municipality as proxy confounders for smoking and time trends, respectively, the adjusted relative risks for the deposition categories were 1.00 (reference < 3 kiloBecquerel/m(2)), 1.05, 1.03, 1.08, 1.10, and 1.21. The excess relative risk was 0.11 per 100 kiloBecquerel/m(2) (95% CI 0.03 to 0.20). Considering the secular trend, directly age standardised cancer incidence rate differences per 100 000 person years between 1988 to 1996 and the reference period 1986-1987, were 30.3 (indicating a time trend in the reference category), 36.8, 42.0, 45.8, 50.1, and 56.4. No clear excess occurred for leukaemia or thyroid cancer.
  
  
  CONCLUSIONS
  Unless attributable to chance or remaining uncontrolled confounding, a slight exposure related increase in total cancer incidence has occurred in northern Sweden after the Chernobyl accident.
authors.affiliation: Division of Occupational and Environmental Medicine, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linköping University, 581 85 Linköping, Sweden. Martin.Tondel@lio.se
authors.forename: Martin
authors.initials: M
authors.lastname: Tondel
authors.forename: Peter
authors.initials: P
authors.lastname: Hjalmarsson
authors.forename: Lennart
authors.initials: L
authors.lastname: Hardell
authors.forename: Göran
authors.initials: G
authors.lastname: Carlsson
authors.forename: Olav
authors.initials: O
authors.lastname: Axelson
mesh_terms: D000293:Adolescent; D000328:Adult; D002588:Cesium Radioisotopes / Q000008:administration & dosage / Q000009:adverse effects; D047852:Chernobyl Nuclear Accident; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology; D011156:Population Density; D011847:Radioactive Fallout / Q000009:adverse effects* / Q000032:analysis; D018788:Radioactive Hazard Release; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout