An examination of occupational and occupationally defined electromagnetic exposures and dementia, vascular dementia, cognitive impairment, and Alzheimer's disease in the Honolulu Asia aging study cohort

Objective. To determine the association of Alzheimer's disease (AD) with occupational job titles assessed with an increased likelihood of having medium to high electromagnetic field (EMF) exposure in Japanese-American men and compare these findings with rates reported for other United States populations and elsewhere.; Design and setting. The Honolulu Asia Aging Study (HAAS), a subset of the Honolulu Heart Program, is a prospective population-based study established in 1965 for the study of cardiovascular disease. Dementing conditions including AD were determined at the follow up Exam 4. Occupations were classified based on the 1970 US Census job titles. A retrospective nested case-control study was conducted.; Participants. Subjects were 3,734 surviving Japanese-American men from HAAS.; Outcome measures. Estimates of occupational EMF exposure were determined by surrogate measures of usual occupation, present occupation, usual industry, occupational classification categories, industrial classification categories, combined selected job titles assessed as having medium to high EMF exposure, and by individual job titles assessed as having medium to high EMF exposure. Odds ratios were estimated, by logistic regression, to assess the association of occupational EMF exposure as a risk factor for AD.; Results. The occupational classifications of Farm Laborers, and Transportation Equipment Operatives had the highest odds ratios of 7.7 and 2.1, respectively with AD. Individually identified occupations with medium to high EMF exposure were carpenters, electricians, tailors, and welders, represented 14.6%, 2.2%, 0.0%, and 1.3% of the participants, respectively. Odds ratios for medium to high EMF occupations for AD ranged from 1.1 to 1.4. Odds ratios for carpenters (1.2), and electricians (1.0) for AD were not statistically significant. The odds ratio for welders and AD was 5.6 (95% CI 1.5–20.7).; Conclusion. The broad occupational classification and industrial classification categories offered little evidence to support an association of EMF exposure and increase rates of AD. The defined grouping of occupations suspected of having exposures to medium and high EMF consistently elevated estimated rates for AD. The lack of statistical significance may be less important than the element of consistency in the estimated rates.