Abstract:Classical programs for environmental monitoring have been supplemented by bioindication measures for a number of years. Investigations on living organisms or their remains (e.g. peat) are frequently used to indicate the environmental situation in either qualitative (bioindication) or quantitative (biomonitoring) terms. This provides pieces of information on environmental burdens of a region at a given point of time or on its changes with time (trend analysis). Classical bioindication often deals with observation and measurements of chemical noxae (both inorganic and organic ones) in well-defined bioindicator plants or animals (including man).
In term of analytical procedures and results, there are parallel developments between progresses in bioindication and innovation in instrument analytical methods. Bioindication approaches usually integrate instrument analytical methods and get information through them. One of the main problems in practice is the representativeness of samples in bioindication approaches and in instrument analytical methods. To get an idea of precision in respect of site and time variations, repeated sampling is necessary in the bioindicator approaches. However, it is difficult to obtain the accuracy of the approach during the sampling procedure since there is no "certified reference system" at present as a calibrator for accuracy in representative sampling. Compared to instrumental analytical methods, a linear range for bioindicators is more difficult to achieve since living organisms are constantly changing their "hardware" by biologically living processes. Therefore, standardisation of bioindicators seems unrealistic at the moment, which means that harmonisation between users of the same indicators is specific and of real concern for the future. It is hard to harmonise scientific and cultural differences in a globalising world because cross-border projects have a tremendous intercultural impact. In spite of that, bioindication may be seen as a gateway to intercultural understanding and as a catalyst for peaceful international cooperation.
A selected monitoring case study of Bejing, China illustrates the new necessity of these methods. Results of Beijing revealed that contents of Cd, Cu and Zn in urban soils of Beijing had insignificant relationship with soil urease activity, while Pb contents in soils had significant negative relationship with soil urease activity. However, urease activity in Beijing urban soil cannot be used as the bioindicator for monitoring Pb pollution in soils because the content of Pb can only explain 10% of the significance.
Based on progresses in bioindication for some 30 years, there are now following lines of further development: 1) more frequent inclusion of multi-element total analyses for a thorough investigation of mutual correlations in the sense of the Biological System of Elements, 2) more work on (analytical) speciation issues to proceed into real effect-oriented environmental sciences, and 3) there should and must be a focus on integrative bioindication methods because for a large number of environmental monitoring problems, a single bioindicator will not provide any meaningful information. Integrative concepts such as the Multi-Markered-Bioindication-Concept (MMBC) provide basic means to get into precautionary environmental protection effects. In conclusion, there is very much interest in integrated monitoring which will require an interdisciplinary design and formation of research groups in future surveys. This would permit rapid and flexible adjustment of the working groups to the particular frame of reference and enable a quick exchange of information between the individual disciplines.