TY - JOUR
T1 - Case-cohort analysis of brain cancer and leukemia in electric utility workers using a refined magnetic field job-exposure matrix
AU - Savitz, David A.
AU - Cai, Jianwen
AU - Van Wijngaarden, Edwin
AU - Loomis, Dana
AU - Mihlan, Gary
AU - Dufort, Vincent
AU - Kleckner, Robert C.
AU - Nylander-French, Leena
AU - Kromhout, Hans
AU - Zhou, Haibo
PY - 2000/9/14
Y1 - 2000/9/14
N2 - Background: The potential association between occupational electric and magnetic field exposure and cancer is well documented in the literature, but there is uncertainty regarding a causal relation. Methods: Using data from a completed cohort study, we sought to refine the job-exposure matrix in a case-cohort analysis by regrouping jobs into more homogeneous groups, but without making additional measurements. From the original cohort, we selected the 164 men who died of leukemia, 145 men who died of brain cancer, and a random subcohort of 800 men (0.6% of the cohort). Erroneous job assignments were corrected and job groups were subdivided based on differences in work environments or tasks performed. Results: Magnetic field exposure remained unrelated to leukemia mortality and positively associated with brain cancer mortality based on both cumulative and average magnetic field indices. Although not monotonic across the middle intervals, increased risk of brain cancer was found in relation to career exposure, with risk ratios of 1.8 (95% CI= 0.7-4.7) and 2.5 (95% CI = 1.0-6.3) in the uppermost categories for cumulative and average exposure, stronger for exposure 2-10 years past. Conclusion: Improvements in exposure assignment based only on reassignment of job titles to occupational categories had little impact on the measured associations of magnetic fields with leukemia or brain cancer. (C) 2000 Wiley-Liss, Inc.
AB - Background: The potential association between occupational electric and magnetic field exposure and cancer is well documented in the literature, but there is uncertainty regarding a causal relation. Methods: Using data from a completed cohort study, we sought to refine the job-exposure matrix in a case-cohort analysis by regrouping jobs into more homogeneous groups, but without making additional measurements. From the original cohort, we selected the 164 men who died of leukemia, 145 men who died of brain cancer, and a random subcohort of 800 men (0.6% of the cohort). Erroneous job assignments were corrected and job groups were subdivided based on differences in work environments or tasks performed. Results: Magnetic field exposure remained unrelated to leukemia mortality and positively associated with brain cancer mortality based on both cumulative and average magnetic field indices. Although not monotonic across the middle intervals, increased risk of brain cancer was found in relation to career exposure, with risk ratios of 1.8 (95% CI= 0.7-4.7) and 2.5 (95% CI = 1.0-6.3) in the uppermost categories for cumulative and average exposure, stronger for exposure 2-10 years past. Conclusion: Improvements in exposure assignment based only on reassignment of job titles to occupational categories had little impact on the measured associations of magnetic fields with leukemia or brain cancer. (C) 2000 Wiley-Liss, Inc.
KW - Brain tumors
KW - Electromagnetic fields
KW - Exposure assessment
KW - Leukemia
UR - http://www.scopus.com/inward/record.url?scp=0033851321&partnerID=8YFLogxK
U2 - 10.1002/1097-0274(200010)38:4<417::AID-AJIM7>3.0.CO;2-W
DO - 10.1002/1097-0274(200010)38:4<417::AID-AJIM7>3.0.CO;2-W
M3 - Article
C2 - 10982982
AN - SCOPUS:0033851321
SN - 0271-3586
VL - 38
SP - 417
EP - 425
JO - American Journal of Industrial Medicine
JF - American Journal of Industrial Medicine
IS - 4
ER -