Follow up study on the immune response to low frequency electromagnetic fields in men and women working in a museum

Seven women and eight men, exposed to low frequency (50 Hz) electromagnetic fields (EMFs) in a museum for 20 hours a week, were investigated in the years 1999 and 2005. During the first study, the mean EMF exposure in the working place was 1.7 microT and 1.1 microT, respectively. In the first investigation, the EMF-exposed men showed reduced blood NK lymphocytes in relation to controls, while EMF-exposed women presented reduced PHA-stimulated IFN-gamma release from peripheral blood mononuclear cells (PBMC). In the year 2005, blood cytotoxic activity, state and trait anxiety (STAI I and II, respectively) and occupational stress were also investigated. The scores of STAI I and II of the control women were slightly higher than those of the control men. EMF-exposed men showed higher occupational stress but normal immune parameters. EMF-exposed women showed, in relation to controls, lower PHA-stimulated IFN-gamma release from PBMC and reduced blood cytotoxic activity/CD45+-CD16+-56+ NK lymphocytes (but not per ml of blood). One of the women exposed to EMF, who worked a night shift, showed marked lymphopenia with very low NK lymphocytes and reduced IFN-gamma release; these immune parameters returned to normal following a change of work site. This study suggests that low frequency EMFs affect the immune functions of women more than those of men. Moreover, the determination of immune parameters seems to be a useful marker of the health effects of exposure to EMFs.