Environmental Risk Assessment

Xenobiotic organic compounds and heavy metals are commonly used in our society in industry, farming and households thus being found in solid waste and wastewater and in runoffs from fields and roads etc. These contaminants have a potential to affect environmental water and soil quality. The risk assessment procedure for chemicals is based on inherent properties of the chemicals with persistence, bioaccumulation, and toxicity as the main criteria. The presence in the environment can either be modeled (predicted) from production volumes and use patterns combined with the inherent properties, or the presence can simply be documented with chemical analysis of environmental samples. Based on the information level of the environmental toxicity of the chemical, “safe” environmental concentrations can be predicted by use of safety factors, and the resulting safe concentrations are then held up against the predicted or measured concentrations. As long as the environmental concentration is below the “safe” concentration we assume that sensitive organisms and ecosystems are not affected by the presence of the chemical. In the opposite situation the environment is at risk, and the risk increases with increasing environmental concentration.

 

The growing use of nanotechnologies will lead to an increasing release of manufactured nanoparticles into the environment. Due to their size, nano-materials have physical-chemical properties that are different from those of their parent materials. Because of this, they behave differently from their parent materials when released into the environment and interact differently with living systems. Thus, these materials call for a different risk assessment procedure than that used on “ordinary” chemicals. Also the presences of mixtures, which actually comprise the general situation, pose a problem. At present the chemicals are assessed one by one, but one chemical is never present alone, there will always be others present as well, but the risk assessment procedure is not fit to handle this situation. Therefore the research area works not only with assessment of chemicals but also with development of new risk assessment procedures to cover new hazardous materials, mixtures, pulse exposures, varying environmental conditions, etc. to make the assessments more environmentally relevant.