Table 4.14 Case-control studies of male breast cancer and occupational exposure to EMF

Reference,
country
Study population
Exposure
classification
Risk estimates
Comments
No.
of cases
RR
(95% CI)
(Matanoski
et al.,
1991);
New York State
(USA)		 Workers 65 employed in one statewide telephone company during 1976-80
Line jobs
Central office technician
(personal monitoring of a
sample of workers
indicates central office
technicians exposed
to mean magnetic
field of 0.25 mT)		 2 6.5 (0.79-24)
 SIR Denominator is state incidence. Cases identified from New York State tumor registry
(Demers
et al.,
1991);
USA		 Cases were 227 male workers in all occupations diagnosed with breast cancer 1983­87. 300 controls matched by age from random-digit dialing and Medicare records. Exposure assignment based on longest-held job reported at interview
All subjects
All electrical occupations 33 1.8 (1.0-3.7)
electric utility trades 13 6.0 (1.7-21)
welders 4 0.8 (0.2-3.1)
Exposed before age 30
and for > 30 years until diagnosis
All electrical occupations 22 3.3 (1.5-7.3)
electric utility trades 11 7.4 (1.6-34)
welders 3 4.3 (0.4-43)
 Risks not altered by adjustment for education, Jewish ethnicity, history of head injuries, exposure to diagnostic X-rays, or BMI
(Loomis,
1992);
USA -
24 states		 Death registration data from 24 states. Cases are men over age 19 who died of breast cancer 1985-88. Occupational data obtained from death record
Age at death less than 65 years
All electrical occupations 3 2.2 (0.6-7.8)
Telephone workers 1 9 (0.9-89)
 OR, controls randomly selected with other causes of death, matched by year of death
(Rosenbaum
et al.,
1994);
New York State &
8 western counties
(USA)		 71 male breast cancer cases reported to a cancer registry 1979-88; 256 controls who participated in a free cancer screening but were found to be disease free. Usual occupation reported in questionnaire, supplemented with city directory information
Job exposure to EMF 6 0.6 (0.2-1.6)
 OR, adjusted for age, county, and occupational heat exposures
The risks from heat exposures were significant (OR = 2.5, CI = 1.0-6.0)
(Stenlund &
Floderus,
1997);
Sweden		 All male workers aged 20-60 in 1980, 56 males diagnosed with breast cancer (adenocarcinoma) 1985-91
TWA magnetic fields All subjects
Quartile 2, 0.16-0.19 µT 17 1.2 (0.6-2.7)
Quartile 3, 0.20-0.28 µT 17 1.3 (0.6-2.8)
Quartile 4, > 0.29 µT 11 0.7 (0.3-1.9)
90th percentile > 0.41 µT 4 0.7 (0.2-2.3)
<60 years
Quartile 2, 0.16-0.19 µT 9 2.9 (0.7-11)
Quartile 3, 0.20-0.28 µT 8 2.5 (0.6-9.5)
Quartile 4, > 0.29 µT 5 0.9 (0.2-4.5)
90th percentile > 0.41 µT 3 1.5 (0.3-8.3)
 OR adjusted for age, education, and solvent exposure
EMF exposure estimate based on job titles identified from the work histories, plus the JEM from the magnetic field measurements in Floderus (Floderus et al., 1993)
OR, odds ratio; CI, confidence interval; SIR, standardized incidence ratio; BMI, body mass index