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In a preliminary study a reduction in natural killer (NK) cell activity in peripheral blood lymphocytes (PBL) was observed in a group of workers exposed to levels of extremely low frequency-magnetic fields (ELF-MF) exceeding 1 microT. This study was performed to confirm the results. In 121 workers engaged in various occupational activities, individual ELF-MF exposure was monitored for 2 work shifts. Exposure levels were calculated as time-weighted average (TWA). Subjects were classified as Low exposure (TWA < or = 0.2 microT), Medium exposure (TWA 0.21-0.99 microT), or Higher exposure (TWA > or = 1 microT). In higher exposure workers NK activity proved significantly reduced compared to low exposure,(p<0.01). In medium exposure a reduction was also observed, but the difference was not significant. Multivariate analysis also confirmed the relation between exposure and NK activity. It has been suggested that ELF might affect tumour progression by inducing changes in the immune system: due to the role played by NK activity in host defence against cancer, the interference with the NK cell activity observed in this study is in agreement with this hypothesis. Furthermore, an increased risk for some neurodegenerative disorders has been reported in some epidemiological studies in ELF-MF-exposed workers: changes in NK function were also described in these diseases. Our results, showing the effect on NK activity of exposure exceeding 1 microT, suggest a possible mechanism for ELF-MF effects. This could open new horizons regarding the adverse long-term effects of these fields.

The main objective of this work was to evaluate the interaction between selenium concentration in both commercial and Se-enriched eggs and other essential/toxic elements (Ca, Mg, Fe, Zn, Pb, and Cd), taking into account a possible synergic action of iodine. Commercial eggs were purchased from several sale points or directly from the producers (farmyard eggs). Fortified eggs were obtained by supplementing chickenfeed for 6 weeks with Se as sodium selenite (1.0 microg/g Se) or Se plus iodine (1.0 microg/g Se+3.7 microg/g I). Se in experimental egg yolks significantly increased over the basic value by 39% in the Se group and 61% in the Se+I group, suggesting that I addition may enhance Se absorption. Levels of Se in commercial yolks were identical in free-range, barn or battery eggs, but significantly lower in farmyard and higher in organic eggs where the Se content approximated that found in Se fortified eggs. A significant reduction in Cd was observed in Se+I treated yolks compared to both control and Se alone diet, thus suggesting a high sensitivity of Cd to the detoxifying effect of Se combined with I. Furthermore, Se+I supplementation was associated with a significant Zn reduction, a finding which needs clarification to avoid attempts to maximize one component affecting the levels of other essential elements.

In an university hospital of about 900 beds, a clinical surveillance was activated to detect cases of Legionnaires' disease in patients affected by community and/or nosocomial-acquired pneumonia. In the hospital Legionella spp was detected in the hot water distribution system and various disinfecting and control procedures were adopted to reduce contamination. Contemporary, the clinical surveillance began with the systematic detection of Legionella urinary antigen among recovered pneumonia, seroconversion as confirmation test and the collection of respiratory secretions or other biological materials to isolate the microorganism in patients positive to the urinary antigen. From September 2003 to May 2005, 486 pneumonia were followed, 98 of which considered of nosocomial origin. In total, 15 cases of community-acquired Legionnaires' disease were detected by the urinary test, whereas no cases of nosocomial origin were found. The characteristics of the detected cases are described in comparison with the other pneumonia and the surveillance cost was evaluated. The systematic clinical surveillance for Legionella infections is feasible with limit costs, allows to detect community-acquired cases otherwise unknown and to ascertain the absence/presence of nosocomial-acquired pneumonia, irrespective of the environment contamination.