Article publication date:
March 2022
Authored by:
Barbant et al.
Summary:
This systematic review and meta-analysis examined the association between extremely low frequency electric and magnetic fields (ELF EMF) and childhood leukemia. The literature search identified 863 studies of which 38 were included in the review. The main meta-analysis included 21 studies and reported a small association between ELF EMF and childhood leukemia when the study results were pooled together (Odds ratio (OR) 1.26; 95% confidence interval (CI) 1.06–1.49). However, when only the 10 studies published after 2000 were assessed the association was no longer present (OR 1.04, 95% CI 0.84-1.29). The authors reported the highest associations between ELF EMF and childhood leukemia in studies that assessed the use of electric blanket (OR 2.75; 95% CI 1.71-4.42) and ELF EMF exposure over 0.4 µT (OR 1.37; 95% CI 1.05–1.80). The authors concluded that prolonged exposure to ELF EMF over 0.4 µT is associated with a greater risk of childhood leukemia.
Link to:
Published In:
Reviews on Environmental Health
Commentary by ARPANSA:
The authors reported a decline in the risk of childhood leukemia in studies post 2000. This declining trend in more recent studies has previously been reported in pooled analyses by Kheifets et al (2010) and Swanson et al (2019). Another recent pooled analysis of over 40 studies by Amoon et al (2021) found no association between ELF EMF and childhood leukemia. The reducing risk that has been observed in recent papers could be due to improved methodology particularly in exposure assessment, however, this isn’t completely clear, and the reduced risk could be due to chance or other factors.
The results from epidemiological studies on the association between childhood leukemia and exposure to ELF EMF have provided conflicting results with both positive and negative associations being reported. There are also problems with the methods in these studies that weaken the conclusion from their results. The factors that could be influencing the observed association include selection bias, misclassification, and other confounding factors (WHO, 2007). These factors are present in the studies used by this meta-analysis, and this prevents a causal association from being made between childhood leukemia and exposure to ELF EMF.
Experimental studies have identified no substantiated biological mechanism that could explain a possible association between ELF MF and childhood leukaemia (SCENIHR, 2015). This, together with shortcomings of the epidemiological studies, limits any conclusions being made on reported associations between ELF MF and childhood leukaemia.
