A non-traditional approach to risk assessment of respiratory exposure to outdoor air pollutants.

The aim of this study was to verify a non-traditional assessment of respiratory exposure to outdoor air pollutants in industrial areas. The technique involved environmental biological monitoring' using domestic rabbits in the neighborhood of a mercury-producing plant. Rabbits were exposed whole-body to mercury emissions for 6 months in special cages near the plant. Control rabbits were kept using the same schedule outside the polluted area. Potential toxicity was assessed by: (a) measurement of Hg-accumulation in lungs and other body tissues by atomic absorption spectroscopy (AAS); (b) scanning electron microscopy (SEM) of the tracheal surface; and (c) measurement of toxic effects on pulmonary alveolar macrophages (PAM) by a rossette assay (Fc immunoglobulin binding). We found increased Hg concentrations in the lungs, kidneys, liver, heart, brain and bone; changes in the mucosal relief of the trachea, and depression of PAM Fc receptor (FcR) activity to IgG. A 6-month chamber exposure of Wistar rats to the aerosol created from solid particles of the mercury-producing plant revealed the increase of Hg-content in the same body tissues except the brain, and, less intense morphologic changes on the tracheal relief. Biomonitoring using environmental exposure of domestic rabbits might be useful in screening for possible health hazards to the respiratory system from complex outdoor aerosols.