An array of occupationally exposure to extremely low frequency electromagnetic fields and light at night on melatonin and related oxidative stress in human subjects

During one decade, an increasing percentage of world population has to be attributed to an array of environmental, health and lifestyle factors. The potential effect of extremely low frequency electromagnetic fields (ELF-EMFs) emitted from electrical and various electrical devices in the occupational environment and light at night (LAN) to elicit biological response are a major concern for the public and scientists. Controversial genetic and oxidative stress effects have been reported by these polluted environments. Hence this study was undertaken with a purpose to evaluate melatonin hormone and oxidative stress markers in exposure workers along with cumulative effects of smoking and drinking. The study subjects (n=342) included night shift workers for more than 2 years with age, gender, socioeconomic status matched non-exposure controls (n=150). Self-reported symptoms were sought using questionnaire. Plasma Melatonin was evaluated using radioimmuno assay. Oxidative stress was estimated by measuring plasma malondialdehyde (MDA), serum nitric oxide (NO) and erythrocyte catalase levels. When the data of exposed subjects was analyzed, a significant decrease in melatonin levels was observed. Plasma MDA levels demonstrated a significant increase in one sub-group. The serum NO levels and erythrocyte catalase levels shows a significant increase. The cumulative effect of a chemical agent or environmental pollutant could be a possible contributor in enhancing the adverse effect of extremely low frequency electromagnetic fields. Certain caution is necessary.