Assessing the potential hazard of chemical substances for the terrestrial environment. Development of hazard classification criteria and quantitative environmental indicators

Hazard assessment constitutes an essential tool in order to evaluate the potential effects of chemical substances on organisms and ecosystems. It includes as a first step, hazard identification, which must detect the potential dangers of the substance (i.e. the kind of effects that the substance may produce), and a second step to quantify each danger and to set the expected dose/response relationships. Hazard assessment plays a key role in the regulation of chemical substances, including pollution control and sustainable development. However, the aquatic environment has largely received more attention than terrestrial ecosystems. This paper presents the extrapolation of several basic concepts from the aquatic to the terrestrial compartment, and suggests possibilities for their regulatory use. Two specific proposals are discussed. The first focuses on the scientific basis of the hazard identification-classification criteria included in the EU regulations and their extrapolation to the terrestrial environment. The second focuses on the OECD programme for environmental indicators and the development of a soil pollution pressure indicator to quantify the potential hazards for the soil compartment and its associated terrestrial ecosystem related to the toxic chemicals applied deliberately (i.e. pesticides) or not (i.e. heavy metals in sludge-based fertilisers; industrial spills) to the soil.