EMF in the News.
Risk of Brain Cancer in Utility Workers Reported by Savitz and Loomis

Savitz and Loomis found no consistent relationship between exposure and leukemia or any of the leukemia subtypes, but a statistically significant increased risk of death from brain tumors with suggestions of a dose-related correlation to average magnetic field intensity and a latency period of 2-10 years. This outcome contrasts with the results of the recent Canadian-French utilities study [Theriault et al., Am J Epidemiol 139:550-572, 1994] which found a significant increased risk of leukemia but not brain tumors. Perhaps the biggest surprise in the study results was their ambiguity: in spite of the improved exposure estimate, the risks were not substantially stronger, weaker, or more consistent than risk estimates produced by much less sophisticated studies based only on job titles. Though the exposure estimates were based on measured values, the relevance of average magnetic field intensity as a metric for exposure assessment and risk characterization is yet to be determined since other field characteristics such as spikes may influence pathologic processes. In their discussion of the results, Savitz and Loomis suggested that future large-scale epidemiological studies (which are both expensive and time-consuming) be postponed until there is a better ability to reconstruct occupational exposures for the critical time period when tumors are expected to form, and/or there is a better understanding of what specific EMF and biological characteristics are important to measure in order to better define relevant exposed and susceptible populations of workers.