Extremely Low Frequency-Magnetic Fields (ELF-EMF) occupational exposure and natural killer activity in peripheral blood lymphocytes

• Published in: The Science of the total environment Vol. 407; no. 3; pp. 1218 - 1223
• Main Authors: Gobba, Fabriziomaria, Bargellini, Annalisa, Scaringi, Meri, Bravo, Giulia, Borella, Paola
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.01.2009; [Amsterdam; New York]: Elsevier Science; Elsevier
• Subjects: Adult; adverse effects; Biological and medical sciences; Carcinogenesis, carcinogens and anticarcinogens; Chemical agents; Electromagnetic Fields; Electromagnetic fields (EMF); Electromagnetic Fields - adverse effects; Environmental Exposure; Environmental Exposure - adverse effects; Environmental Monitoring; Female; Humans; Immune system; immunology; Killer Cells, Natural; Killer Cells, Natural - immunology; labor; Lymphocytes; Lymphocytes - immunology; Male; Medical sciences; Middle Aged; multivariate analysis; natural killer cells; occupational exposure; Occupational Exposure - adverse effects; Personal monitoring; Smoking; Time Factors; Time-Weighted Average (TWA); Tumors; Workers; Italy; Europe; Electromagnetic fields (EMF); Personal monitoring; Time-Weighted Average (TWA); Workers; Immune system; Human; Immunopathology; Toxicity; Occupational exposure; Blood; Biological monitoring; Natural killer cell; Carcinogen; Health and environment; Extremely low frequency; Electromagnetic field; Biological effect; Magnetic field; Lymphocyte; Occupational medicine; Public health
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2008.08.012

Extremely Low Frequency-Magnetic Fields (ELF-MF) are possible carcinogens to humans and some data suggest that they can act as promoters or progressors. Since NK cells play a major role in the control of cancer development, an adverse effect on ELF-MF on NK function has been hypothesized. We examined NK activity in 52 workers exposed to different levels of ELF-MF in various activities. Individual exposure was monitored during 3 complete work-shifts using personal dosimeters. Environmental exposure was also monitored. ELF-MF levels in the workers were expressed as Time-Weighted Average (TWA) values. NK activity was measured in peripheral blood lymphocytes (PBL). In the whole group the median occupational TWA was 0.21 µT. According to the TWA levels, workers were classified as low exposed (26 subjects, TWA ≤ 0.2 µT) and higher exposed workers (26 subjects; TWA > 0.2 µT). In higher exposed workers, we observed a trend to reduce NK activity compared to low exposed, but the difference was not significant. Then we selected a subgroup of highest exposed workers (12 subjects; TWA > 1 µT); no difference was observed between low and highest exposed subjects in the main personal variables. Considering both E: T ratios from 12:1 to 50:1 and Lytic Units, a significant reduction in NK activity was observed in the highest exposed workers compared to the low exposed. Multivariate analysis showed a significant negative correlation between exposure and LU, while no correlation was evidenced with other personal characteristics. ELF-MF are considered possible carcinogens, and existing data suggest that they can act as promoters. Due to the role of NK activity in host defence against cancer, the results obtained in this study in workers exposed to ELF-MF levels exceeding 1 µT are in agreement with this hypothesis, and support the need for further investigation in this field.