Radiofrequency exposure and mortality from cancer of the brain and lymphatic/hematopoietic systems

The proliferation of wireless communication technologies has raised public concern regarding potential health effects of radiofrequency (RF) exposures . This is the first report of findings from a large-cohort mortality study among employees of Motorola, a manufacturer of wireless communication produ cts. We examined all major causes of mortality, with brain cancers, lymphom as, and leukemias as a priori outcomes of interest. Using job titles, we cl assified workers into high, moderate, low, and background RF exposure group s. A total of 195,775 workers contributed 2.7 million person-years during t he 1976-1996 period. Using external comparisons, the standardized mortality ratios for RF-exposed workers were 0.53 [95% confidence interval (CI) = 0. 21-1.09] and 0.54 (95% CI = 0.33-0.83) for central nervous system/brain can cers and all lymphomas/leukemias. Rate ratios calculated from Poisson regre ssion models based on internal comparisons were near 1.0 for brain cancers and below 1.0 for all lymphomas and leukemias. These findings were consiste nt across cumulative, peak, and usual exposure classifications. We did not observe higher risk with increased exposure duration or latency. Although t his study is limited by the use of a qualitative exposure matrix and the re latively young age of the cohort, our findings do not support an associatio n between occupational RF exposure and brain cancers or lymphoma/leukemia.