Maternal occupational exposure to electromagnetic fields before, during, and after pregnancy in relation to risks of childhood cancers: Findings from the Oxford survey of childhood cancers, 1953-1981 deaths

Abstract

Background The concern that maternal exposure to electomagnetic fields (EMF) might be related to childhood cancer risks, particularly leukemia risks. Methods Maternal occupational data already collected as part of the Oxford Survey of Childhood Cancers have been reviewed. Information on occupations held before, during, and after the pregnancy was sought for 15,041 children dying of cancer in Great Britain in the period 1953–1981, and for an equal number of matched controls. Each period of working was classified under one of five headings: (1) sewing machinist; (2) textile industry workers (other than sewing machinists) with likely exposures to EMF; (3) other machinists and other jobs with likely “higher” EMF exposure; (4) other jobs with likely exposure to some EMF, and (5) jobs with little potential for EMF exposure. Results Relative to risks in the children of mothers who held occupations with little potential for EMF exposure during pregnancy (a category that included housewives), risks of all childhood cancers were close to unity both for the children of sewing machinists (22 case and 31 control mothers, RR 0.72, 95% CI 0.42 to 1.25) and for the children of other machinists with likely “higher” EMF exposures (44 case and 47 control mothers, RR 0.93, 95% CI 0.61 to 1.41). Corresponding risks for all childhood leukemias and for all childhood brain cancers were similarly unexceptional. Simultaneous adjustment for social class, maternal age at birth of child, and sibship position had little effect. Conclusions The study findings did not indicate that maternal occupational exposure to EMF during pregnancy is a risk factor for childhood leukemias, childhood brain cancers, or the generality of all childhood cancers. Am. J. Ind. Med. 35:348–357, 1999. © 1999 Wiley‐Liss, Inc.

Risk of childhood acute lymphoblastic leukaemia following parental occupational exposure to extremely low frequency electromagnetic fields

“…In that study, exposure was derived by linking job title to a job exposure matrix. Likewise, Sorahan et al (1999) reporting on 15 276 matched childhood cancer cases and controls (6610 leukaemias) from a large English national case–control study found no excess risk for all childhood leukaemia types in mothers who were exposed to ELF before, during or after pregnancy. Again, that study derived exposure from job title.…”

“…Studies that inferred exposure to ELF fields from the job title (Sorahan et al , 1999) or by relating job title to a job exposure matrix (Hug et al , 2010) generally did not find an association with either maternal or paternal exposure. However, McKinney et al (1991) found an increased risk in the offspring of mothers who worked in catering, cleaning and hairdressing and food-related occupations in the 40 weeks before conception although no specific range of occupations accounted for the increased risk.…”

A Systematic Review and Meta-analysis of Childhood Leukemia and Parental Occupational Pesticide Exposure

“…Other potential risk factors include preconceptual paternal occupational exposure to solvents (Buckley et al 1989), motor exhaust fumes (Vianna et al 1984), or electromagnetic fields (Feychting et al 2000; Pearce et al 2007); prenatal maternal alcohol consumption (for AML) (Shu et al 1996); and reduced occurrence of common infections during childhood (Ma et al 2005). Prenatal maternal occupational electromagnetic field exposure was linked to childhood leukemia in a Canadian case–control study (Infante-Rivard and Deadman 2003) but not in two other case–control studies (Feychting et al 2000; Sorahan et al 1999). …”

Parental Occupational Exposures and Risk of Childhood Acute Leukemia

“…A limited number of studies, conducted by assigning exposure from the job title or relating a job title to a matrix, found a positive association between paternal exposure and offspring leukemia risk ( 18 , 19 ). Contradictory data have emerged, regarding maternal exposure, an association with a moderately increased risk ( 20 ) while other no association ( 21 ). In agreement, more recent large case-control studies concluded that pre- and postconceptional paternal and maternal exposure to low-frequency magnetic fields is not linked to increased childhood leukemia risk ( 17 , 22 ).…”