Combined influence of quartz dust, ozone and NO2 on chemotactic mobility, release of chemotactic factors and other cytokines by macrophages in vitro.

In this study the single as well as combined effects of quartz, ozone and nitrogen dioxide (NO2) on some immunofunctions of bovine alveolar macrophages (BAM) were investigated. After incubation with 10 micrograms/ml of particles the chemotactic response of BAM is increased nonspecifically, whereas after incubation with 100 micrograms/ml of quartz chemotaxis is specifically decreased. In addition, quartz induces tumor necrosis factor alpha (TNF-alpha) and chemokines to be released dependent on the concentration. Ozone by itself is also a very potent inducer of the release of chemokines and TNF-alpha, but in combination with ozone, quartz has not more than an additive effect. NO2 alone suppresses drastically the release of TNF-alpha. The results show that quartz, ozone and NO2 alter some immunofunctions of BAM and that by combining toxic particles such as quartz with these gases, additive but not synergistic effects might be expected.