Schwermetalle in Regenwürmern Baden-Württembergs

Goal and Scope

Since 1984 the Environmental Protection Agency (LfU) of the State of Baden-Wuerttemberg has been investigating the heavy metal burden of earthworms from representative long-term forest observation plots. These investigations are aimed at elucidating and assessing adverse effects of pollutants on the soil biocenosis.

Methods

At first only lead and cadmium were measured in the worms; in repetitive measurements over the years further metals or metalloid elements such as aluminum, arsenic, chromium, cobalt, copper, manganese, mercury, nickel, thallium, vanadium, and zinc were added to the agenda.

Results and Conclusion

The frequency distribution of the metals in the earthworms was characterized statistically. For the first time state-wide background values, normal values and threshold values were established for all the elements measured. A comparable study with a similar range of parameters is known neither nationally nor internationally. Time trend studies have been available for lead and cadmium since 1985/86, and for zinc since 1987. The studies show a steady decrease of the heavy metals on a state-wide average and especially in the ‘Odenwald’ and ‘Black Forest’ hills with their formerly highly polluted earthworm habitats. Today, the level of these metals in the earthworms is low with few exceptions. This holds true for other heavy metals as well.

Recommendations and Perspectives

The state-wide decreasing very low heavy metal burden of forest observation plots far from known emission sources can be considered a success of air pollution abatement measures. Because of the ongoing atmospheric deposition of heavy metals, regular observation should continue in order to estimate time trends and to recommend the reduction of emissions when precautionary values (part 2) are exceeded.     

Factors influencing survival in case of shipwreck and other maritime disasters in the Danish merchant fleet since 1970

During the last 40 years, merchant ships have become safer and a number of new safety measures have been introduced. The purpose of the first part of this study was to investigate the trend of fatalities due to maritime disasters in the Danish merchant fleet over a 40-year period from 1970 to 2009, during which a total of 146 seafarers lost their lives. The relative risk of fatal accidents in the period 1990–2009 compared with the period 1970–1989 was 0.81 (CI: 0.58–1.14).The second part of the study focuses on seafarers who abandoned a merchant ship in the period from 1990 to 2009. The purpose was to investigate factors influencing survival. During the 20-year period 44 incidents were identified involving a total of 267 seafarers. Among these, 51 did not survive. The fatality risk for seafarers on small and large ships was 3.68 and 0.64 per 1000 years at risk, respectively. Among the 171 seafarers who were rescued dry, one was injured and did not survive (0.6%). Out of 64 seafarers ending up in the water, 18 (28%) did not survive. Among the remaining 32 seafarers, 23 were with great certainty inside the vessel when it sank and another nine may have remained inside the sinking vessel. None of these survived. Suboptimal organisation of the evacuation process was of importance in some cases. Survival suits and automatic emergency transmitters (EPIRB’s) have been shown to work in practice but their introduction has had limited influence on survival statistics.     

Ökologische Kriterien der Technik- und Stoffbewertung: Integration des Vorsorgeprinzips

The development of criteria for the comparative assessment of technologies and substances beyond the toxicological approach and the development of an integrated pattern of criteria is still at the beginning. The criteria presented here for integrating the precautionary principle into the substance and technology assessment have to be further operationlised and completed, in the same way as the criteria which have been discussed and developed within the framework of

- the poisoning and pollutant paradigm

- the equilibrium paradigm

- the sustainability and “Mitwelt” paradigm

- the energy and the general technology assessment debate.

The resolution of the criteria has to be improved and their range (which is certainly limited) has to be explored more precisely. The application of the criteria should never occur mechanically. Technology assessment and substance assessment are not only scientific, but essentially social and, hence, discursive processes. It is not so much the assessment of individual substances which should be in the center of the debate, but rather the comparative assessment of competing techniques, substances and substancerelated development pathways (see vonGleich andRubik, 1966 as a first approach to assess the environmental effects of old and new materials). According to the example of the energy strategies, only the development of competing strategies in the substance field could create the necessary prerequisites for a broad public discourse and thus for a democratisation of the basic substancerelated policy decisions. This discourse is a duty which science and economy have toward society.     

Eine Apparatur zur kontinuierlichen Respirationsmessung an marinen Organismen

Measurements were made with a Clark electrode in a closed system under conditions of different, regulatable water current velocities. Six simultaneous parallel measurements are possible with only one electrode. The volume of respiration chambers amounts to 80 ml for small animals and 300 ml for larger ones. Technical details of the apparatus and measuring procedures are described. The accuracy amounts to 0.5 μl O₂ for the 80 ml chamber, and 2 μl O₂ for the 300 ml chambers. The apparatus has been successfully used on various marine evertebrates and algae.     

Abwasserbehandlung beim kontrollierten Rückbau einer Pflanzenschutzmittelfabrik

During the demolition of an industrial building contaminated with chlorophenols and polychlorinated dibenzodioxins (from Boehringer & Sohn in Hamburg-Moorfleet, Germany), several measures must be taken in order to protect the surroundings. Since these compounds are strongly adsorbed by particulate matter, a mist is continuously sprayed over the whole building. The waste water is expected to be highly contaminated and must therefore undergo extensive purification procedures. The primary goal of the existing study is to examine whether or not the present effluent reprocessing unit, a system which is comprised of a charcoal filter, is able to clean the waste water according to legal requirements. Secondly, the main factors that influence the clean up of the effluent were investigated in order to design a suitable precleaning unit for the contaminated water should the present reprocessing unit not fulfill these requirements. By means of the factorial design technique, the effect of three factors (flow velocity of the water, amount of charcoal and the pH-value) on the efficiency of the cleaning process and with regard to chlorophenols was examined. Surprisingly, the pH-value does not have a significant effect on the efficiency. In addition, the results of the experiments show that a precleaning of the effluent is not required.