A NONTRADITIONAL APPROACH TO RISK ASSESSMENT OF RESPIRATORY EXPOSURE TO OUTDOOR AIR-POLLUTANTS

The aim of this study was to verify a non-traditional assessment of re spiratory exposure to outdoor air pollutants in industrial areas. The technique involved 'environmental biological monitoring' using domesti c rabbits in the neighborhood of a mercury-producing plant. Rabbits we re exposed whole-body to mercury emissions for 6 months in special cag es near the plant. Control rabbits were kept using the same schedule o utside the polluted area. Potential toxicity was assessed by: (a) meas urement of Hg-accumulation in lungs and other body tissues by atomic a bsorption spectroscopy (AAS); (b) scanning electron microscopy (SEM) o f the tracheal surface; and (c) measurement of toxic effects on pulmon ary 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 tra chea, and depression of PAM Fc receptor (FcR) activity to IgG. A 6-mon th chamber exposure of Wistar rats to the aerosol created from solid p articles of the mercury-producing plant revealed the increase of Hg-co ntent in the same body tissues except the brain, and, less intense mor phologic changes on the tracheal relief. Biomonitoring using environme ntal exposure of domestic. rabbits might be useful in screening for po ssible health hazards to the respiratory system from complex outdoor a erosols.