Occupational Exposure to Magnetic Fields and Brain Tumors in Taiwan

Abstract

P-542 Introduction: To address the possible associations between the occupational exposures to electronic magnetic fields (EMF) and the risk of brain cancer. Methods: A total of 111 cases of primary brain cancer and 235 controls were collected from a hospital-based case control study. The exposure assessment has separated workers into three different groups of occupational exposure due to different strength of electronic magnetic field. Three exposure level groups are “non-exposure”, “possible-exposure”, and “explicit-exposure”. Result: After adjusted the age, gender, smoking, drinking and home environment, a significantly increased risk of brain tumour was observed among subjects who had ever held job with an magnetic fields “explicit- exposure” relative to those “non-exposure” (odds ratio=4.68, 95% confidence interval: 1.50∼14.57) but not significantly in “possible-exposure” (odds ratio =1.09, 95% confidence interval: 0.56∼2.12). Besides, a significantly increased risk of brain tumour was observed among man who had ever held job with an magnetic fields “explicit-exposure” relative to those “non-exposure” (odds ratio =7.37, 95% confidence interval:1.36∼40.03). However, the significantly increased risk of brain tumour was not observed for women. Among the 111 brain cancer cases, 44 of them are meningioma, 14 are pituitary adenoma, 21 are acoustic neuroma, 10 are glioma, 19 are under different categories, and 3 of them are uncertain. The cases were furthered analyzed by histopathology groups, the results for “explicit- exposure” group has higher odds ratio value than “possible-exposure” group when compared to “non-exposure” as reference group. Especially, the odds ratio is 7.39 (95% confidence interval =1.91∼28.54) for acoustic neuroma cases when the magnetic fields “explicit- exposure” relative to those “non-exposure”, and the odds ratio is. 6.22 (95% confidence interval =1.51∼25.73) for Glioma cases when “possible-exposure” group relative to “non-exposure” group, these odds ratios show statistical significance. Conclusion and discussion: Our findings support the hypothesis that occupational exposure of electromagnetic fields may increase the risk of brain cancer. In the previous study, the categories of brain tumors’ histopathology were not explored carefully. However, in our study we separated those cases into many different groups by histopathology such as (meningioma, pituitary adenoma, acoustic neuroma, glioma (include astrocytoma)) and others five categories. We found that there were higher risks of acoustic neuroma and glioma in “explicit- exposure” and “possible-exposure” groups respectively.