According to the legislative framework of the EU, critical pollutant levels (EQS) and tolerance levels have been determined for the protection of vegetation. In addition, according to Greek and international literature, the impact of the air pollutants on vegetation is important and harmful, given that Particulate Matter (PM) or chemical compounds emitted during the construction or operation phase of an activity are entering the plants stomas.

In general prolonged exposure to air pollutant emissions leads to premature aging and breaking of leaves, while continuous exposure of the canopy leaves to -not so- high concentrations causes chronic leaf damage, such as e.g. chlorosis and extensive leaf breaking. On the other hand, continuous exposure to high concentrations of air pollutants may lead to necrosis of the leaf (necrosis of brown and black-brown colour) and smudging.

In Green2Sustain we can estimate the probability, the degradation intensity, by the exposure of various groups of flora species to different pollutant emission patterns (doses). Given that impacts may be different to certain species like coniferous or broad-leaved species and the like, an analytical assessment is usually needed to understand the impacts and define the proper protective or mitigation measures and monitoring.