Childhood Cancer and Nuclear Power Plants in Switzerland

Details are available from the special CANUPIS-Homepage:


This study will address the question if residence in the proximity of a nuclear power plant is associated with an increased risk of childhood cancer, and whether this can be explained by confounding, particularly by other area-based risk factors for childhood cancer which might cluster around nuclear power plants.

Study Description

Background: Since the reporting of a cluster of leukaemia cases around Sellafield in 1984, numerous studies have assessed the risk of childhood cancer and residence in the proximity of nuclear power plants (NPPs). These studies showed heterogeneous results, many with weak positive associations. An explanation for this excess is lacking. Emissions from nuclear power plants during normal operation are low in comparison to the annual background exposure and dose-response studies do not support a causal association. A recent case-control study from Germany, showing a small but statistically significant increase in the risk of cancer, particularly leukaemia, in children aged less than five years living near NPPs refuelled the public discussion about this potential hazard. The study, as many others, had methodological problems limiting the interpretability of the results, including i) a potential selection bias because of differential response rates of municipalities; ii) possible bias due to selection of controls by local clerks; iii) lack of adjustment for potential confounding factors such as electric power lines, major roads, socio-economic status, and other factors; and iv) analysis of residency at the time of cancer diagnosis only (because of the known latency in development of malignant diseases, the place of residence prior to the diagnosis is of great interest).

Aims: To investigate, whether living near a NPP increases the risk of childhood cancer in general, and childhood leukaemia in particular.

Methods: This is a census-based cohort study with national coverage. Selection bias will be minimized by using geo-coded addresses for each child, important potential confounders will be adjusted for, and residential history back to the date of birth will be included. The study uses the Swiss National Cohort (SNC), a long-term, census-based, multipurpose cohort and research platform including all Swiss inhabitants (6.8 million people) to estimate person-years at risk. Cases are identified via the Swiss Childhood Cancer Registry (SCCR), a national registry of all children diagnosed with cancer. We will include all patients born between January 1985 and December 2007, aged <16 years at diagnosis and resident in Switzerland.

Our main exposure is proximity to nuclear sites modelled as four categories (the inner 5 km zone, 5-10 km, 10-15 km and >15 km). The following confounders will be included: distance to major roads, electric power lines and broadcast transmitters, natural ionising radiation, area statistics (e.g. pesticides from agriculture or golf courses), pollutants from industry), and degree of urbanisation, socioeconomic status (using the Sotomo-Index) and average number of children per family at communal level.

Significance: This study will add importantly to the current evidence base on the risk of childhood cancer and residence in the proximity of nuclear sites. It will overcome important methodological problems of previous studies. Given the fact that additional nuclear sites are currently planned in Switzerland, the topic is of high public health and policy relevance. Finally, the study will examine a number of other exposures suspected to cause cancer in children.


Spycher BD, Feller M, Zwahlen M, Röösli M, von der Weid NX, Hengartner H, Egger M, Kuehni CE.
Childhood cancer and nuclear power plants in Switzerland: a census-based cohort study.
International Journal of Epidemiology 2011. Doi:10.1093/ije/dyr115.

Kuehni CE, Feller M, Egger M.
Response to: Sufficient statistical power for CANUPIS?
Bulletin Suisse du Cancer (Schweizer Krebsbulletin) 2010;2:129-130.

Kuehni CE, von der Weid NX, Hengartner H, Niggli F, Röösli M, Huss A, Feller M, Egger M.
CANUPIS - Childhood Cancer and Nuclear Power Plants in Switzerland.
Bulletin Suisse du Cancer (Schweizer Krebsbulletin) 2008;28:266-268.

Study Team

Kuehni, Claudia (PL / PD Dr. med.). Dept of Social and Preventive Medicine, University of Berne
- Röösli, Martin. Institute of Social and Preventive Medicine, University of Basel
- Huss, Anke. Institute for Risk Assessment Sciences, University of Utrecht, Netherland


- Von der Weid, Nicolas. Pediatric Oncology, CHUV Lausanne
- Niggli, Felix. Center of clinical research, University of Zurich
- Hengartner, Heinz. Ostschweizer Kinderspital, St. Gallen
- Egger, Matthias. Institute of Social and Preventive Medicine, University of Berne


- Swiss Paediatric Oncology Group (SPOG)
- Federal Office of Public Health (FOPH)


Oncosuisse/Krebsliga Schweiz. KLS 02224-03-2008

Project Duration




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