Review date
March 2024
Article publication date
December 2023
Summary
This case-control study examined the association between extremely low frequency electric and magnetic fields (ELF EMF) and all types of childhood leukeamia and or childhood acute lymphoblastic leukeamia. The study included 182 cases of childhood leukeamia and 726 population controls matched on sex, year of birth and residential area. Exposure to ELF EMF was assessed based on proximity to transformer station and participants were assigned to the exposed category if they lived within 15 or 25 meters of a transformer station. Distance to a substation was determined based on residential address. Potential confounders were mitigated by adjusting the results for traffic-related air quality, distance from high voltage powerlines, annual fuel supply of petrol stations within 1000 meters and urban area density or agricultural crop density within 100 meters. The authors reported no association between proximity of less than 15 meters to transformer stations and childhood leukeamia (<15 m, odd ratios (OR) 1.0; confidence interval (CI) 0.2 – 4.9) or childhood acute lymphoblastic leukeamia (<15 m: OR 1.0; CI 0.2 – 4.9). They also reported no association between proximity of less than 25 meters to transformer stations and childhood leukeamia (<25 m: OR 1.2; CI 0.4 – 3.4) or childhood acute lymphoblastic leukeamia (<25 m: OR 0.7; CI 0.2 – 2.6). The authors also found no association between proximity of less than 15 or 25 meters to transformer stations and any childhood leukeamia type when age was split by the <5 and ≥ 5 years of age.
Published in
Environmental Research
Link to
Residential exposure to magnetic fields from transformer stations and risk of childhood leukemia
ARPANSA commentary
The authors make statements throughout their discussion that their results provide evidence for association between residential proximity to transformer stations and childhood leukeamia. This is false for several reasons. Firstly, they do not report any statistically significant association between distance to transformer stations and any childhood leukeamia. Secondly, they make these claims based on evidence that only includes at most 5 exposed cases. Thirdly, the study assigned exposure to participants who live less than 15 or 25 meters from transformer stations, however, measurements have shown that when you are between 3-7 meters away from a transformer the associated ELF EMF will on average be <0.4 µT. When more than 10 meters away ELF EMF will usually be <0.2 µT (Kandel et al 2013). The average magnetic field in the home can range from <0.1 to 1 µT. This indicates that the proximity of participants to transformer stations may have had no effect on their ELF EMF exposure level or their likelihood to develop childhood leukeamia, unless their home was extremely close to a transformer station. Overall, the claims made by the authors are baseless and due to the methodical shortcomings of the study it provides no evidence of an association with childhood leukaemia.
Some epidemiological studies observing outcomes from exposure to ELF MF greater than 0.3 or 0.4 µT have shown an association with childhood leukaemia (SCENIHR 2015). However, this association has not been established by consistent scientific evidence. The epidemiological evidence for this association is weakened by various methodological problems such as potential selection bias, misclassification and confounding. Furthermore, it is not supported by laboratory or animal studies and no credible theoretical mechanism has been proposed on how ELF MF could cause cancer. Overall, the scientific evidence does not establish that exposure to ELF EMF in the everyday environment is a hazard to human health.
