Averting possible negative consequences for humans and the environment due to the continually increasing number of chemical products necessitates a sound scientific basis and continuous research. With the aid of basic research-oriented environmental chemistry and ecotoxicology, mechanisms are to be detected and described in such a way as to enable predictions to be made which will lead to a benefit for humans and the environment.
Until today environmental chemistry and ecotoxicology have been considered to be, above all, a cost factor. Money is only made available when disasters have already occurred. Fear among the public after the Seveso accident (a chemical accident near Milan in 1976) or oil spills helped to give a financial thrust to research in the areas of environmental chemistry and ecotoxicology. However, diminishing public interest has led to a decline in funding. The lack of continuity in this area runs counter to the requirement to make chemicals systematically more environmentally sound and to avoid harmful effects from the beginning. Nevertheless, continuous, systematic research will be unavoidable in view of a large number of facts:
Today, 60 million chemicals are known all over the world. 100,000 synthetically manufactured sub-stances are used as industrial chemicals in Europe alone. In addition, there are thousands of active agents in pesticides, pharmaceuticals and biocides, washing and cleaning agents, food additives and cosmetics and the transformation and reaction products of all these substances in the environment. Chemical production will expand in the coming years, especially in developing countries. The consequences for living beings and for the quality of environmental resources like air, water and soilcan only be answered by using a sound scientific basis.
Environmental chemistry and ecotoxicology – two new scientific disciplines
This task is a major challenge for the two new scientific disciplines of environmental chemistry and ecotoxicology. After the Second World War the chemical industry boomed and concern about harmful impacts of chemical substances on the environment grew. At the end of the 1960s the first discussions on environmental protection issues began. Against this background, the two scientific disciplines of environmental chemistry and ecotoxicology as an interdisciplinary mixture of chemi-stry, biology and toxicology came into being.
Environmental chemistry is concerned with the spreading, transformation and fate of chemical sub-stances from natural and anthropogenic sources with regard to the biotic and abiotic environment. It develops scientific strategies and concepts to identify the occurrence and behavior of chemicals in different environmental media at an early stage in order to evaluate them and to avoid them as far as possi¬ble. Ecotoxicology focuses on the effects of chemical substances on the biotic environment, in other words the impact on and hazards to different organisms. Both disciplines are intertwined and closely linked with other scientific disciplines such as biology, ecology, hydrology, agricultural sciences, chemistry and toxicology.
Urgent need for action
The social and practical relevance of the disciplines will increase. The growth in population and con-sumption and the associated increased requirement for food, resources and energy will result in quantitatively and numerically more chemical substances being produced and disposed of. This demands national and international framework conditions in order to protect the environ¬ment from the undesired effects of these substances. However, sound assessments can be made and management measures can be taken only if they are scientifically sound . The Water Framework Directive (WRR L) and the European chemical regulation REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) are two good examples of this. However, neither of these can be put into practice without an efficient risk assessment of chemicals.
Example - the Water Framework Directive: 90 percent of the rivers and lakes in Germany have attained the good chemical condition required by the WRR L. However, only some ten percent of surface waters have reached the necessary good ecological condition. This finding might lead to the belief that chemicals scarcely represent a hazard today. On the one hand, the 30 substances in standard use to assess water quality are hardly still in use today or their use has even been prohibited. On the other hand, thousands of substances currently reaching bodies of water in micro quantities and as mixtures have not yet been subjected to toxicological assessment. In this case the question should be considered whether the substance mixtures occurring have different effects than the other substances. Such assumptions can only be tested with a new research approach which skillfully combines chemical and effect-oriented analytics. The broad range and close linkage of different disciplines at the UFZ offer excellent conditions for this.
Example - the chemicals regulation: REACH obliges manufacturers or importers to determine hazardous properties of industrial chemicals and natural substances to assess their effects on health and the environment and to provide information about them. This applies to substances to be brought on and traded on the market and for an estimated 30,000 old chemicals which were put on the market in quantities of one ton and more per year before 1981., Chemicals are to be made safe from production via consumption to disposal with REACH. However, animal experiments are still very often necessary to determine the human and ecotoxicological properties of the chemicals. At UFZ various teams are therefore pursuing the aim of replacing standard test programs in the environmental risk assessment of chemicals based on animal experiments by intelligent test strategies. By using alternative testing methods and theoretical checking methods the aim of reducing the number of animal experiments despite the increasing number of chemical tests can be achieved. Inexpensive approaches are both experimental in vitro tests and computer-based models (QSAR, Quantitative or Qualitative Structure-Activity Relationships) and important decision-making tools (read across methods).
What if chemicals are already in the environment?
Until the aim is reached of developing chemicals and their life cycles in an optimum way as regards their environmental properties there is still a long road ahead of science, industry and politics. This also applies to the identification of chemicals which are already in the environment and necessitate a rehabilitation of contaminated sites. How can pollutants be removed from soils or bodies of water? Under which conditions are ecosystems able to provide the “pollutant degradation“service for humans? How can these degradation capacities of microorganisms be made useful or supported? Where are innovative physical-chemical solutions necessary? Answers to these questions must be provided by field tests, as the transfer of good environmental technology solutions from the laboratory to marketable technologies requires this. There are excellent conditions for this at UFZ for example pilot plants and research platforms such as TERENO (Terrestrial Environmental Observatories).
And what if humans are affected?
If chemicals are responsible for undesired environmental aftereffects, humans are also often af-fected, for they are part of the environment. Human reactions to environmental stressors are often conveyed via the immune system. For this reason it is being investigated, as part of health research at the UFZ, how environmental chemicals affect cells of the human immune system and contribute to environment-related diseases such as allergies. System biology is becoming increasingly important in this research. It combines biology, mathematics and physics in experimental and model-based approaches in order to understand biological processes in cells, tissues and organisms as a whole and to develop prevention strategies using this knowledge.
With the core topic “Chemicals in the environment and health“ the UFZ researchers wish to contribute to making chemicals ecocompatible and to protecting humans and the environment.