VDI 2310 Blatt 6:2018-07

Besides the negative influence to human health ground-level ozone (O3) as a main component of the photochemical 'summer smog' is currently the most important air pollutant for plants. There are currently two approaches to derive critical stress limits for vegetation for O3: an approach related to exposure concentrations, which can theoretically be applied to all species of the plant kingdom, and an approach based on cumulative stomatary O3 uptake. This only applies to target organisms with stomata and thus includes all higher plants, especially vascular plants. The standard reflects current scientific knowledge, describes and defines critical indices for ozone doses (critical levels) for agricultural plants, species-rich grassland and forests, and derives target values on the basis of frequency of forecasts. Sensitive representatives for the vegetation types mentioned before are wheat, various grassland species such as red clover and the round leaf bellflower or beeches. The risk assessment is based on the evaluation of the stomatal O3 uptake due to receptor-specific deposition models and on dose-response-curves for the system-relevant effect indicators mentioned.