Assessment of the vegetation risk by fluoride emissions from fertiliser industries at Cubatão, Brazil

The Atlantic Rain Forest near the industrial complex of Cubatao, south-eastern Brazil, suffers from the impact of severe air pollution. Gaseous and particulate fluorides which are emitted by fertiliser plants are assumed to play an important role in the forest decline. In order to obtain information on the air pollution situation and the spatial and temporal distribution of pollution effects, standardised bioindication methods from temperate climates were introduced and applied during a three-year study. A sensitive Gladiolus cultivar developed typical fluoride-induced leaf lesions in areas affected by airborne fluorides, and Lolium multiflorum cultures accumulated large quantities of fluoride. Highly significant linear regression was found between foliar fluoride contents of both species as well as between leaf damage and fluoride accumulation in Gladiolus plants. By using these indicator species, four different areas of the region were identified with respect to vegetation risk by airborne fluorides.