A new in-vitro-testing concept (vector-model) in biological screening and monitoring the lung toxicity of dusts. Presentation of the concept and testing the method with dust of known lung toxicity

The health effects of a dust may not be correctly estimated by material ana lysis only. Therefore additional biological methods for risk assessment are required. First choice method is inhalative exposure, but exposure experim ents are expensive in time and money. A more practicable method is the in-v itro-testing in cultured cells. However, the routinely used classic assays (cytotoxicity-methods) are of low specifity. Therefore a new in-vitro-testi ng concept was developed. It is based on the knowledge of the primary react ions of aveolar macrophages (AM) activated by the phagocytosis of dust part icles. Depending on the type of dust phagocytosis of par tides stimulates o r inhibits distinct reactions of AM. Alterations in the state of the AM can induce pathogenic changes in the alveolar environment, which are followed by manifest lung diseases (fibrosis, emphysema, cancer). The AM state and t he AM secretory products can be measured in cultures of isolated AM. Certai n reactions (vitality, membrane damage) or secretory products (enzymes, med iators, radical molecules) can be regarded as independent "vectors" of the AM dust reaction. Analysis and combination of the vectors ("vector model") gives multidimensional reaction patterns. In tests using dusts of known in vivo reaction (inert, fibrotic, carcinogenic) the vector model was shown to be more sensitive and specific compared to the classic testing method usin g only a single vector.