Study type: Epidemiological study (observational study)

Exposure to Radio-Frequency Electromagnetic Fields From Broadcast Transmitters and Risk of Childhood Cancer: A Census-based Cohort Study. epidem.

Published in: Am J Epidemiol 2014; 179 (7): 843-851

Aim of study (acc. to author)

A cohort study was conducted in Switzerland to investigate the association between exposure to radiofrequency electromagnetic fields from broadcast transmitters and childhood cancer, particularly leukemia and tumors of the central nervous system.

Further details

Two strategies to analyze the data were applied: a time-to-event analysis and an incidence density cohort analysis. For the time-to-event analysis, we included children who were under age 16 years and living in Switzerland on the date of the 2000 census. Time at risk started on the date of the census and lasted until the date of diagnosis, death, emigration, the child's 16th birthday, or December 31, 2008, whichever occurred first. For the incidence density cohort analysis, no linkage between SCCR and Swiss National Cohort data was necessary. We included in this cohort all SCCR-registered patients diagnosed between January 1985 and December 2008 and residing in Switzerland at the time of diagnosis.

Endpoint/type of risk estimation

Type of risk estimation: (hazard ratio, incidence rate ratio)

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 exposure to radio-frequency electromagnetic fields from broadcast transmitters: < 0.05 V/m
Group 2 exposure to radio-frequency electromagnetic fields from broadcast transmitters: 0.05 - 0.2 V/m
Group 3 exposure to radio-frequency electromagnetic fields from broadcast transmitters: > 0.2 V/m

Population

Study size

Type Value
Total 1,332,944
Eligible 1,287,354
Other:

7,627,646 person-years

Statistical analysis method: ( adjustment: )

Conclusion (acc. to author)

Eleven percent of all children were exposed to a predicted radio-frequency electromagnetic fields between 0.05 V/m and 0.2 V/m, and 4% were exposed above 0.2 V/m. From the whole study sample, 51% lived within the modeled area.
Based on 997 cancer cases, adjusted hazard ratios in the time-to-event analysis for the highest exposure category (>0.2 V/m) as compared with the reference category (<0.05 V/m) were 1.03 (CI 0.74-1.43) for all cancer types, 0.55 (CI 0.26-1.19) for childhood leukemia, and 1.68 (CI 0.98-2.91) for childhood central nervous system tumors. Results of the incidence density analysis, based on 4,246 cancer cases, were similar for all types of cancer and leukemia but did not indicate a central nervous system tumor risk (incidence rate ratio 1.03, CI 0.73-1.46).
The authors concluded that the results of this study did not suggest an association between predicted exposure to radio-frequency electromagnetic fields from broadcasting and the risk of childhood leukemia. Results for central nervous system tumors were less consistent, but the most comprehensive analysis did not suggest an association.

Study funded by

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