Efficiency of biomonitoring methods applying tropical bioindicator plants for assessing the phytoxicity of the air pollutants in SE, Brazil

Abstract

In the tropical region, the greatest challenge of the biomonitoring approach is to establish linear relationships between biomarkers measured in plants and pollutant concentrations, since the bioindicator responses can be intensified or restricted by climatic variations. In southeastern Brazil, there are two regions affected by air pollution, where the Atlantic Forest remains and should be preserved. Consequently, both areas have been monitored by biomonitoring procedures using standardized and tropical plants. The industrial complex settled in Cubatão is one of the world's most famous examples of environmental pollution and degradation, with consequent decline of the Atlantic Forest. An oil refinery is among the most polluting industries in the Cubatão region. The other region is located in the Metropolitan Region of Campinas (MRC). The MRC has been affected by high levels of air pollutants originated from road traffic and is responsible for over 80% of CO, NOx, and hydrocarbon emissions and develops industrial activities that emit about 70% of the particulate matter present in the region. Both regions are distinguished by the climate, despite the fact that they are only about 130 km far from each other. Several studies carried out by our group in these regions aimed to establish the best native tree species and respective potential biomarkers for future assessment of pollution effects on tropical Forests. We present a critical review about the efficiency of native species compared to standardized bioindicator plants considering antioxidant defense system, nutrient accumulation, and microscopic aspects when exposed to atmospheric pollutants and climate.