Biological and biochemical effects of air pollutants: synergistic effects of sulphite.

Air pollution has become a major public and political concern since the beginning of industrialization, particularly motor exhaust over the past three decades. Epidemiological studies, together with clinical trials and experiments in exposition chambers (including biochemical model reactions), have contributed to our knowledge of potential dangers and increased our understanding of the corresponding mechanisms and dose-response effects. Comparison of the threatening reports that appear almost daily in the press with the digest of over 800 scientific publications allows the statement that the impact of ozone and nitric oxide on the health and performance of plants and animals is widely overestimated and appears to be used as a political instrument. In contrast, the combination of SO2 with soot and asbestos particles may represent an underestimated toxic potential. In this communication, we shall concentrate on basic redox mechanisms involving SO2 and important target molecules, as well as looking at the cooperative effects of sulphite and soot particles.