Assessment of the effects of nocturnal exposure to 50-Hz magnetic fields on the human circadian system. A comprehensive study of biochemical variables

The proposed laboratory investigation was designed to evaluate the effects of acute exposure to both continuous and intermittent magnetic fields (MFs) (50 Hz-10 mu T) on the circadian rhythm of clinical chemistry variables in humans: electrolytes (magnesium, calcium, phosphorus, sodium, potassium, a nd chloride), enzymes (amylase, lipase, aldolase, gamma glutamyltransferase [GGT], lactate dehydrogenase [LDH], aspartate aminotransferase [ASAT], and alkaline phosphatase [ALP]), lipids (cholesterol, high-density lipoprotein [HDL], apolipoprotein A1 [ApoA1], and ApoB), proteins (total proteins and albumin), nitrogen substances (uric acid, urea,and creatinine), iron,: glyc emia, and transferrin. Young volunteers (32 subjects: 16 exposed and 16 sha m exposed) were selected according to the screening criteria. Each subject participated in two sessions held within a 4-week period. In the first sess ion, one group of volunteers (16 subjects) was exposed to a continuous MF a nd then, in the second session, to an intermittent MF. The second group (16 subjects) served as a control for both sessions. At each: session, blood s amples were collected at 3h intervals from 11:00 to 20:00 and hourly from 2 2:00 to 08:00. The results indicate that both continuous and intermittent 5 0-Hz linearly polarized MFs of 10 mu T intensity have no effects on the cir cadian rhythms or on the levels of the variables studied here.