Pesticides are a bigger problem than had long been assumed. This is the conclusion of a study in which scientists analysed data on 500 organic substances in the basins of four major European rivers.
It was revealed that 38 per cent of these chemicals are present in concentrations which could potentially have an effect on organisms. According to scientists writing in the journal "Science of the Total Environment", this conclusion clearly shows that contamination by organic chemicals is a problem throughout Europe.
Most of the substances classified as a risk to the environment in the study were pesticides; the majority of these are not on the European list of priority substances which have to be monitored regularly. They therefore believe that the list of chemicals specified by the EU Water Framework Directive as having to be monitored by national authorities urgently needs to be revised.
The aim of the EU Water Framework Directive is that surface water and groundwater bodies should reach a good environmental and chemical status by 2015. The chemical status will be assessed based on a list of 33 so-called priority pollutants. As over 14 million chemicals are on the market and over 100,000 of these are produced on an industrial scale, the authorities have to confine their monitoring to a manageable number of pollutants. Throughout Europe scientists are therefore working on methods to establish which pollutants these should be.
An important contribution to this has now been made by a study completed by the scientists of the Helmholtz Centre for Environmental Research (UFZ) together with colleagues in France, Slovakia, Belgium and Spain. They analysed a database compiled for the EU MODELKEY research project which contains five million records on physicochemical data. The study focused on organic pollutants recorded in over 750,000 entries of water analyses in the basins of the Elbe (Czech Republic/Germany), the Danube (10 neighbouring European countries), the Schelde (Belgium) and the Llobregat (Spain) rivers. According to the European Commission, this is the first study which has developed a system which has classified organic pollutants on the basis of assessment criteria and the need for action.
One of the most frequently registered compounds was diethylhexyl phthalate (DEHP), a chemically-produced softener which may impair fertility and is therefore banned in the EU from 2015. This is followed by another softener bisphenol A (BPA), which may also impair fertility, and diclofenac and ibuprofen, two pharmaceutical substances used commonly in painkillers.
The scientists classified a total of 73 compounds as potential priority pollutants. Around two thirds of these are pesticides, i.e. products used in agriculture to protect crops against disease, pests and weeds. The most problematic pesticides were diazinon, which is already no longer allowed in Germany and Austria, as well as azoxystrobin and terbuthylazine, which are still allowed in Central Europe. "Neither of these pesticides is on the list of 33 priority pollutants, which have to be monitored by authorities throughout the EU," explains UFZ researcher Dr. C. Peter von der Ohe. "Terbuthylazine is a compound that is structurally closely related to the priority pollutants simazine and atrazine, which may not be applied any more. This is a nice example how small structural modifications of chemical products may apparently improve the chemical status without mitigating any hazards to the aquatic ecosystems." Thus, the scientists strongly support that the priority pollutant list is regularly updated. Today the majority of the substances currently presenting problems are not listed, while many of the chemicals being monitored have been banned for some time and are no longer used. "We were also surprised that substances previously classified as harmless, such as HHCB, which is used as a synthetic musk fragrance in personal care products, are present in the environment in alarming concentrations," adds Dr. Werner Brack of the UFZ, who advises the European Commission in various committees and projects on the revision of the list of priority pollutants. "In our opinion the development of the Water Framework Directive should ensure that in future not only the presence of chemical substances but also their effects are monitored," suggests Brack.For all of the criticism that the water authorities in Europe are currently paying too little attention to pesticides and that the list of priority pollutants should be revised, in the opinion of the scientists the study also reveals the first successes of the Water Framework Directive. One third of the pollutants classified as priority a few years ago by the EU now no longer present a risk to the rivers studied.
http://www.ufz.de/index.php?en=5366In the Helmholtz Centre for Environmental Research (UFZ) scientists are researching the causes and consequences of far-reaching changes to the environment. They are concerned with water resources, biological diversity, the consequences of climate change and adaptability, environmental and biotechnologies, bioenergy, the behaviour of chemicals in the environment, their effect on health, modelling and social science issues. Their guiding theme: Our research contributes to the sustainable use of natural resources and helps to secure this basis for life for the long term under the effects of global change. The UFZ employs 1,000 people in Leipzig, Halle and Magdeburg. It is financed by the federal government and the federal states of Saxony and Saxony-Anhalt.
http://www.ufz.de/The Helmholtz Association contributes towards solving major and pressing social, scientific and economic issues with scientific excellence in six research areas: Energy, Earth and Environment, Health, Key Technologies, Structure of Matter and Aeronautics, and Space and Transport. The Helmholtz Association is Germany's largest scientific organisation with over 31,000 employees in 17 research centres and an annual budget of approximately 3 billion euros. Its work stands in the tradition of the naturalist Hermann von Helmholtz (1821-1894).
Tilo Arnhold | UFZ News
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