A field and laboratory study focused on the effects of exposure to emissions originating from a mercury recycling plant on the respiratory immunity was conducted. The reason for the study was to elucidate the association between the exposure to emissions and the increased morbidity for respiratory diseases reported in the residing children. To simulate the children's respiratory exposure, an animal model in the polluted area was used. A group of Wister rats was respiratorily exposed during six months to the pollutants in the ambient air in a location of the regional elementary school. Comparing to a non-exposed control group, the increased mercury concentration (considered as biomarker of exposure to mercury) and iron concentration (as biomarker of the exposure to solid particulates containing iron as their major component) in body tissues of animals exposed outdoors were detected. The results indicated the burden of the respiratory system with the inhaled airborne pollutants (mercury vapor and solid particulates containing various metals) derived from the mercury recycling plant as well as their translocation to the other body tissues. In addition, the activity of pulmonary alveolar macrophages (PAM) lavaged from Wistar rat lungs following the intratracheal treatment with particulates derived from mercury recycling emissions was examined. A statistically significantly decreased PAM count, PAM viability and phagocytic activity found in the exposed animals indicated cytotoxic effects of the inhaled particulates on PAM count and activities. In relation to the cytotoxic effects, a slightly increased lactate dehydrogenase and acid phosphatase activities in bronchoalveolar lavage (BAL) were found. These animal data revealed a depressive effect of airborne particulates derived from the mercury recycling plant on PAM activities. Furthermore, the findings pointed to a presumable impairment of the lung clearance capability based on the phagocytosis and further transport of the inhaled particulates of various origin by pulmonary alveolar macrophages on the tracheobronchial escalator.

        Key words: mercury recycling emissions, animal biomonitoring model, pulmonary alveolar macrophages (PAM), bronchoalveolar lavage (BAL), cytotoxicity, immune respiratory disorders