Table 4.10

Table 4.10 Epidemiological studies of exposure to EMF and cancer at all sites

Reference;
type of study;
country

Cohort description

Exposure
classification

All cancers

Comments

No. of cases

RR for cases^a (95% CI)

(Tynes et al., 1992);
cohort,
Norway

37945 male workers (age 20-70) followed 1961-85 in the Cancer Registry of Norway

12 electrical occupations

3806

1.1 (1.0-1.1)

SIR adjusted for age

(Sahl et al., 1993);
cohort,
California (USA)

Southern California Edison Company utility workers, mortality from 1960-88, 36221 workers in cohort

Electrical occupations in utility

261

1.1 (0.92-1.3)

Internal cohort RR, adjusted for age

(Thériault et al., 1994);
case-control,
Canada and France

Male utility workers in 3 large companies: base population of 223292; 4151 cancer cases; 6106 controls. Cumulative exposure from job history and magnetic field JEM

Cumulative magnetic fields
> median > 3.1 mT - year	2158	1.0 (0.91-1.1)
> 90^th percentile > 16 µT - year	443	1.0 (0.86-1.2)

OR, adjusted for social class from case-control analysis with magnetic field JEM

(Savitz & Loomis, 1995);
cohort,
USA

138905 men employed for > 6 months in 5 electric utilities were followed for mortality from 1950-86

Cumulative magnetic fields		Total exposure:
highest category, > 4.3 µT-year	505	1.2 (1.1-1.4)
exposure response, RR/µT-year	4833	1.0 (1.0-1.0)

Internal cohort RR, adjusted for age, year, race, class, work status, PCBs, and solvent exposures

		Past 2-10 years:
highest category, > 0.7 µT-year	746	1.1 (1.0-1.3)
exposure response, RR/µT-year	4833	1.1 (1.0-1.2)

(Guénel et al., 1996)
case-control,
France

EDF cohort of (Thériault et al., 1994); 170000 men in cohort with 1915 cases of cancer matched to 7568 controls

Cumulative electric fields
highest category > 414 V/m-year	195	0.89 (0.74-1.1)
exposure response, OR per 500 V/m-year	986	0.89 (0.75-1.0)

OR, adjusted for social class

PCB, polychlorinated biphenyl

^aAll RRs are normalized to the null hypothesis = 1.0