The use of Parmotrema tinctorum (Parmeliaceae) as a bioindicator of air pollution

Abstract

Air quality monitoring by automatic stations, although efficient, does not allow evaluating the effects of pollution on living organisms and communities. Thus, the aim of the present study was to use lichens of the Parmotrema tinctorum species in active air quality biomonitoring. We used a new methodology of chlorosis area analyses in QGis software, as low-cost and complementary tool to physicochemical methods. Samples of the aforementioned species were exposed to atmospheric pollution for 30 consecutive days in the dry and rainy seasons, in urban and industrial regions. The chlorosis rate (34% of the lichen thalli, on average) and the accumulation of sulfur (1.1 g.kg-1, on average) were higher in the samples of lichens exposed in the industrial region, in the dry season. There was a moderate-to-high positive correlation between chlorosis rate and lichen content of nitrogen, sulfur, iron and zinc, in the dry season, mainly with sulfur (r = 0.71). The results confirmed the sensitive of P. tinctorum to atmospheric pollution, even after a short exposure time. Such new active biomonitoring methodology (chlorosis analysis in the QGis) can be used in future studies of air quality assessment by environmental and health surveillance managers.