Trace substance

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The collective term trace substances is understood to mean, above all, undesirable, microscopic , dissolved substances in water , which are also referred to as micropollutants or micropollutants. These are synthetic substances that occur in concentrations of nano- to a few micrograms per liter of water. The term trace substances is usually used in connection with water treatment and has nothing to do with (vital) trace elements . In the legislation of the European Union , trace substances are used together with other substances under the term `` priority substances ''.

Overview

Trace substances comprise different groups of substances, for example pesticides , polycyclic aromatic hydrocarbons , industrial and household chemicals, organic chlorine compounds, plasticizers, substances from personal care products, but also sweeteners and many other synthetic chemical compounds. Heavy metals are not counted among the trace substances. Problems often arise with these substances due to their bioaccumulation (accumulation in the tissue), their persistence (longevity), their toxicity (toxicity) or because they can hardly be removed from wastewater with the technologies commonly used today. A group of micropollutants that has been in focus for a number of years is drug residues .

Problem

Trace substances are introduced into the environment mostly through municipal and industrial wastewater , but sometimes also through diffuse sources (e.g. direct deposition from the air, leaching from contaminated soil or through agriculture). Trace substances contained in wastewater can often not or only incompletely be eliminated in sewage treatment plants and can thus be detected in sewage sludge and (purified) wastewater. Trace substances then reach surface waters or groundwater via this path and can also accumulate there in sediments and in the soil. The number of organic chemical compounds is now more than 50 million substances worldwide and the entry of anthropogenic trace substances into the environment continues to increase. The American Chemical Society has already recorded the occurrence of more than 100,000 organic and inorganic chemical substances. The Expert Council for Environmental Issues has classified around 5,000 substances as potentially environmentally relevant. In 2010, the European Chemicals Agency provided evidence of the use of more than 400 harmful, carcinogenic chemicals in various products. The entry of trace substances into ecosystems and thus possibly also into the food cycle can lead to very different consequences. The proof of a harmful effect is for many substances such. B. carried out with micro- algae , water fleas and zebrafish . Usually only the effects of individual substances are examined. In nature, however, organisms are exposed to a large number of different substances, the harmful effects of which can hardly be estimated in combination. In the case of many trace substances, the waste water entry pathway comes primarily from the production and use of substances in industry and households. A reduction of the inputs even before the wastewater treatment - i.e. for the users - would be expedient, since even modern sewage treatment plants with more extensive treatment processes cannot guarantee complete elimination.

Problem with drug residues

As far as purified wastewater is discharged into surface water and this results in the entry of non-eliminable trace substances, these substances may also end up in the drinking water. The Netherlands receive z. B. 37% of drinking water from surface waters, mainly from bank filtrate on the Rhine and Meuse . Particular attention is given here to drug residues. German drinking water catchment areas and rivers now also show drug residues such as X-ray contrast media and other substances. Residues of pesticides and other pharmaceutical trace substances in groundwater and surface water often come from agriculture. An evaluation by the Federal Environment Agency of measuring programs in the federal states from 2009 to 2011 shows that a total of 27 different active pharmaceutical ingredients from eight active ingredient classes were measured in concentrations of over 0.1 micrograms per liter in German surface waters. In addition to the X-ray contrast media, the frequently used pain reliever diclofenac also showed noticeably high concentrations . For many trace substances there are still no limit values ​​for wastewater treatment or drinking water treatment because their occurrence was discovered relatively late in some cases or there is insufficient knowledge about their effects or potential for damage.

Framework for action in the European Union

In January 2012, the EU published a draft list of priority substances for the Water Framework Directive . Priority substances are those that are classified as a significant risk for the aquatic environment. The German Federal Surface Waters Ordinance already contained 33 priority substances that had been defined by the European Union . The new EU Directive 2013/39 / EU now defines twelve new substances that have been included in the EU list of priority substances, with corresponding adoption in the national legislation of the member states:

The newly established limit values ​​(environmental quality standards) for these substances will come into force in 2018. The EU member states are obliged to submit additional measures and monitoring programs to the EU Commission by 2018 so that a `` good chemical status '' of all surface waters for these substances can be achieved by 2027.

Dealing with drug residues at EU level

Around 3,000 active pharmaceutical ingredients are currently approved in the European Union. Pharmaceutical trace substances have been increasingly detected in wastewater since the 1990s due to ever-improving analytical methods . After their use, the substances not absorbed by the body are excreted or washed off. Studies show excretion rates of the active ingredients between 30% and 70% for orally taken drugs and even higher rates when taking into account externally applied creams or gels. In 2013, three active pharmaceutical ingredients were placed on the watch list of the Water Framework Directive for the first time (the two hormones estradiol and ethinylestradiol and the pain reliever diclofenac ), and in 2015 three further macrolide antibiotics . The aim of introducing a European watch list was to update the available information on the mode of action of the substances listed there in water in order to enable a better risk assessment. As a result of Directive 2013/39 / EU '', the EU Commission is developing ... a strategic approach against the pollution of water by pharmaceutical substances ... If necessary, proposals to take greater account of ... the environmental compatibility of pharmaceuticals [during authorization and] ... if necessary, by ... 2017 measures ... to address the possible environmental impacts of pharmaceutical substances [...], discharges, emissions and losses of such substances into the aquatic environment, taking into account the Reduce public health requirements and the cost-effectiveness of the proposed measures. ''

Possible solutions

For the elimination of a large part of the known trace substances, which have not yet been fully recorded by the biological sewage treatment plants that are common today, strategies for installing more extensive cleaning processes in sewage treatment plants are being discussed in several European countries.

Solutions for drug residues

As part of EU-funded cooperation projects of several countries (Germany, France, Luxembourg, the Netherlands, Scotland, Switzerland), studies have been carried out which, with regard to pharmaceutical trace substances, dealt with the question of avoidance and reduction on the consumer side and also examined technologies for wastewater treatment . The underlying idea here was that around 20% of human pharmaceuticals in wastewater come from hospitals and around 80% from domestic wastewater. On the one hand, hospital sewage treatment plants were designed that treat the highly concentrated hospital wastewater with different technologies and allow conclusions to be drawn about the efficiency of certain technologies with regard to the large number of drugs, metabolites (metabolic products) and antibiotic- resistant germs. In the EU-funded cooperation projects, studies were carried out over several years at temporary hospital sewage treatment plants in Esch-sur-Alzette and the Baden district (Aargau) as well as permanently installed hospital sewage treatment plants in Zwolle and Gelsenkirchen , the results of which in turn were based on the results from municipal sewage treatment plants with extended technology from the Lippeverband and Annemasse were compared. On the other hand, the willingness of the population to change consumption and disposal behavior was determined in test regions with investigations, cooperation with doctors and pharmacists, information events and campaigns, whereby both information deficits and incorrect disposal represent a burden that should not be underestimated: Up to 24% of Germans in one Interview actions admitted frequent or occasional disposal of liquid medication via the toilet / sink. In another representative survey in 2006, 16% of those questioned stated that they at least occasionally dispose of unused tablets in the toilet / sink. Here too, up to 43% of those questioned occasionally disposed of liquid medicines via the sink or toilet. As a result, the greatest possible scope of measures at the information and educational level, as well as the withdrawal of medicines and the support of doctors, pharmacists and medical specialists, seem to enable a reduction in the introduction of medicines into the water cycle. Improved wastewater treatment at point sources such as large hospitals or in sewage treatment plant catchment areas with increased drug contamination (e.g. health resorts ) or in particularly sensitive natural areas (e.g. drinking water catchment areas) can also be useful. However, none of the technologies used in the projects (treatment with membrane technology , ozone , UV light, activated carbon , sand filters ) resulted in a complete elimination of all pharmaceutical trace substances, not even in the combination of several technologies. If their use is to be pursued further, achievable goals should first be defined, e.g. B. for the percentage elimination of the sum of all substances or for the targeted treatment of selected substances. For example, Switzerland has formulated the goal of reducing freight by 80% using selected indicators. The introduction of further treatment stages always leads to increased energy consumption. It usually increases by 5 - 30% compared to normal operation. Depending on the size of the plant, the quality of the wastewater and the process used, the increase can also be higher.

Political approaches to solutions in German-speaking countries

Solutions in German-speaking EU member states will essentially be based on an EU framework, as around 80% of national environmental legislation today has its origin in EU legislation. In the EU Sewage Sludge Directive and its annexes, for example, many substances are listed that serve to protect the environment and especially the soil when sewage sludge is used in agriculture. Basically, it is recognized throughout Europe that the strategy of 1. avoidance (e.g. by replacing substances with less harmful substances or through correct disposal), 2. minimization (reduction of consumption or use) and only in the third Step the elimination should be followed by technical measures. Further measures can be the stricter environmental impact assessment for the approval of new substances or the review of substances already approved on the EU internal market.

For the treatment of drinking water, the Federal Environment Agency is gradually laying down 'health orientation values' (GOW) for individual substances. Decisions on how to deal with the challenges of eliminating pharmaceutical residues in wastewater treatment in Germany are discussed less at federal level than at the 16 federal states. Above all, the state governments of North Rhine-Westphalia (NRW) and Baden-Württemberg (BW) are trying to induce the operators of sewage treatment plants to carry out a technical expansion, although the legal basis (such as binding limit values) is missing. Basically no separate collection of Altmedikamenten provided in Germany, as in most parts of household waste in the waste incineration is so medicines can be disposed without damage. Due to incorrect disposal, trace substances still get into the wastewater and in this way into the environment, so there seems to be a need for action.

In Switzerland, the expansion of all large sewage treatment plants is being promoted to eliminate trace substances. Sewage treatment plants with more than 80,000 connected people are affected. In March 2014, the Swiss National Council approved the amendment to the Water Protection Act with regard to the polluter-based financing of the elimination of micropollutants in wastewater. This means that by the end of 2040, 75% of the investment costs for upgrading 100 of the total of 700 Swiss wastewater treatment plants (ARA) will be covered by a nationwide financing solution. To co-finance the measures, a maximum of nine francs is levied on all ARAs in Switzerland per affiliated resident. The ARA finance this tax by increasing their existing wastewater charges.

In Austria, pharmaceuticals are defined as problematic substances and are therefore considered to be hazardous waste that is collected separately. The same applies in Luxembourg. Here, too, before taking their own measures to reduce micropollutants, the political development at the European level is awaited and closely cooperated with the International Commission for the Protection of the Rhine.

Web links

Individual evidence

  1. ↑ Competence Center Micropollutants NRW
  2. ^ Website of the American Chemical Society
  3. ↑ a b Report of the NRW Ministry of the Environment  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Toter Link / www.umwelt.nrw.de  
  4. ↑ Human pharmaceuticals in the water cycle, STOWA 2013 report ( Memento of the original from September 25, 2015 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.masterplan-wasser.nrw.de
  5. ↑ Regional thematic report by the State of Lower Saxony, drug and X-ray contrast agent residues in groundwater
  6. ^ Bavarian State Office for the Environment
  7. ↑ a b c background paper of the Federal Environment Agency, 2014
  8. ↑ EU press release on the Water Framework Directive
  9. ↑ Eco-directed sustainable prescribing: feasibility for reducing water contamination by drugs, 2014
  10. ↑ a b BIO Intelligence Service (2013), Study on the environmental risks of medicinal products, Final Report prepared for Executive Agency for Health and Consumers
  11. ↑ EU Directive from 2013 (PDF)
  12. ↑ Implementation decision of the EU Commission, 2015 (PDF)
  13. ↑ Website of the Interreg project Pharmaceutical Input and Elimination from Local Sources ( Memento of the original from April 24, 2018 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.pills-project.eu
  14. ↑ a b c d final report noPILLS in waters, 2015
  15. ^ Portrait of the Luxembourg hospital project
  16. ↑ Portrait of the Gelsenkirchen hospital project
  17. ↑ a b Publication of the START project ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.start-project.de
  18. ↑ Swiss Federal Office for the Environment, 2012 '
  19. ↑ Stavros Dimas, EU Environment Commissioner 2004-2010
  20. ↑ EU Sewage Sludge Directive
  21. ↑ Federal Environment Agency: Toxicology of drinking water
  22. ^ Report from the Federal Ministry of Health and the Federal Environment Agency to consumers on the quality of water for human consumption (drinking water) in Germany
  23. ^ Statement from the Ministry of the Environment in Baden-Württemberg, 2015
  24. ↑ Winznau sewage treatment plant - brand new does not necessarily mean ultra-modern. In: srf.ch . August 30, 2019, accessed August 31, 2019 .
  25. ↑ Presentation Administration de la gestion de l'eau, 2015
  26. ↑ ICPR website