Highlights of a report on the European aquatic environment: hazardous substances in fresh and marine waters


“Highlights” by GreenFacts of this technical report of the European Environmental Agency (EEA)

 In summary :

The main aims of this report are:

  1.  to document the sources, pathways, emissions and discharges of selected hazardous substances to Europe’s fresh and marine waters and provide an overview of the current status of, and recent trends in, chemical pollution ofEurope’s in these waters;
  2. to describe some of the impacts that hazardous substances can have upon aquatic biota and outline the potential for human exposure to these substances via water;
  3. to outline key European policy and legislation that addresses the use of hazardous substances and their release to water and highlight selected measures to reduce these emissions;
  4. to present tools and innovative approaches to assess the sources, levels and effects of hazardous  substances, including chemical mixtures.

Note :  The term ‘hazardous substances’ is used throught this report in a broad sense, encompassing a.e. substances of very high concern as defined by the European regulation REACH on chemicals, the hazardous substances as defined by the OSPAR marine Convention (covering the North Atlantic Ocean and the North Sea) or the potentially wide-ranging list of substances for which EU Member States are to establish their own surface and groundwater standards.

The report in nine questions (and answers !)

1.   What are the substances dangerous for the aquatic environment ?

 Whilst synthetic chemicals clearly bring important benefits to society, says the report, some of them are hazardous, raising concerns for human health and the environment depending on their pattern of use and the potential for exposure. Certain types of naturally occurring chemicals, such as metals, can also be hazardous.

2.  How hazardous are the substances emitted to the aquatic environment ?

 These substances comprise a wide range of industrial and household chemicals, metals, pesticides and pharmaceuticals. Hazardous substances are emitted to water bodies both directly and indirectly through a range of diffuse and point sources from a wide range of land-based and marine sources, including agriculture and aquaculture, industry, oil exploration, mining activities, transport, shipping and waste disposal, as well as our own homes.

Emissions of hazardous substances to the environment can occur at every stage of their life cycle, from production, processing, manufacturing and use in downstream production sectors or by the general public to their eventual disposal. Sources include industrial activitis of course but also the urban environment, agriculture, mining, landfills and contaminated areas.  For example, whilst household and industrial wastewater treatment has been implemented progressively acrossEurope, the process does not remove all hazardous substances, with household and industrial chemicals and pharmaceuticals, for example, being detected in treated effluent that is subsequently discharged to surface waters.  In addition, concern regarding chemical contamination arising from the exploitation of shale gas has grown recently.

 3. What are the effects of hazardous substances in water ?

 The presence of hazardous substances in fresh and marine waters and associated biota and sediment is documented by various information sources. Hazardous substances can have detrimental effects on aquatic biota at molecular, cellular, tissue, organ and ecosystem level. Substances with endocrine‑disrupting properties, for example, have been shown to impair reproduction in fish and shellfish inEurope, raising concerns for fertility and population survival. The impact of organochlorines upon sea birds and marine mammals is also well documented, as is the toxicity of metals and pesticides to freshwater biota. From a socio‑economic point of view, such impacts diminish the services provided by aquatic ecosystems, and consequently the revenue that can be derived from them.

 4. Can these hazardous substancs pose risks to human health ?

Human exposure to man-made chemicals has been implicated in a range of chronic diseases, including cancer as well as reproductive and developmental impairment. Such exposure can be linked to the presence of hazardous substances in water, through the ingestion of contaminated drinking water and the consumption of contaminated freshwater fish and seafood.

The exceedance of regulatory levels in seafood is documented, says the report,  for several hazardous substances in the seas aroundEurope. In addition, whilst human exposure to mercury in the Arctic, in part through the consumption of marine food, has declined, concentrations in the blood of more than 75 % of women sampled inGreenlandexceed US guideline levels.

Concerns also extend to potential effects arising from human exposure to a mixture of chemicals via various pathways, as found in the more polluted water bodies ofEurope. Laboratory studies have shown that the combined effects of chemicals upon aquatic life can be additive resulting in observable detrimental effects for combinations of chemicals even if these are present, individually, at levels below which any adverse effects can be detected.

The presence of hazardous substances in drinking water supplies requires their removal. A key measure for reducing the level of purification required forEurope’s drinking water, says the report, is the establishment of safeguard or protection zones around the source and must be associated with regulatory powers to control polluting activities.

 5. What are the legislations designed to protect Europe’s waters ?

Europe has introduced a range of relatively recent legislation to address the use of chemicals and their emissions to the environment, including water. The Regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), designed to improve the protection of human health and the environment from the risks posed by chemicals, has a key role to play in this respect. REACH attributes greater responsibility to industry with regard to managing these risks and providing safety information on substances used. The Regulation also calls for the progressive substitution of the most dangerous chemicals once suitable alternatives have been identified.

Nowadays, the chemical quality of Europe’s surface waters is primarily addressed by the recently adopted Environmental Quality Standards Directive (EQS Directive) which defines concentration limits for pollutants of EU-wide relevance known as priority substances (PSs). Some of these pollutants have been designated as priority hazardous substances (PHSs) due to their toxicity, their persistence in the environment and their bioaccumulation in plant and animal tissues for which the EQS Directive requires cessation or phase-out of discharges, emissions and losses of priority hazardous substances. Other substances identified as being of concern at local, river basin or national level, standards have to be set at national level. Compliance with this requirement is critical, underlines the report.

Abatement measures established under the EU Integrated Pollution Prevention and Control (IPPC) Directive have also contributed to a decline in metal emissions to water and air, whilst legislation relating to the production, use and disposal of polychlorinated biphenyls (PCBs) has resulted in declines in concentrations found in marine biota. A similar outcome has resulted from the banning of tributyltin (TBT) in anti‑fouling paints due to its endocrine-disrupting impacts on marine invertebrates, although high levels in marine sediments can still be observed in certain locations.

6. What are the present challenges regarding hazardous substances aquatic environment ? 

Data show that hazardous substances can be found at high concentrations among others in three of the European seas. In the case of DDT, hexchlorobenzene (HCB), lindane and PCBs, this observation reflects their persistence in the aquatic environment, given that all four are now banned withinEurope. In certain locations, metal concentrations exceed the maximum levels set by legislation.

In many cases however, declining trends are observed. In theNorth-East Atlantic, concentrations of cadmium, DDT, lead, lindane and PCBs are all declining, reflecting the decrease in riverine loads. The reports indicates declining trends are also evident for lindane in the Baltic Sea, although data from other sources indicate declining trends in PCBs in herring, perch and mussels in several locations in the Baltic sea. the banning of TBT has led to clear downward trends of concentrations in marine snails in the North Atlantic region and in the Baltic Sea.Some hazardous substances like for example mercury, tributyltin and polyaromatic hydrocarbons,are hydrophobic and tend to accumulate in sediment and biota, with the result that their concentrations in these matrices are likely to be higher and, therefore, more detectable and measurable than in water. If measurements are made in the water column, the risk to the aquatic environment may be underestimated.

Although regulation has led to documented reductions in the emissions of such substances to air and water (indeed, the presence of many is a legacy of past use), their persistence and ubiquity, particularly in sediment and biota, mean that they continue to pose a risk to aquatic environments even at sites far from human activity. An harmonisation at EU level is, therefore, desirable says the report.

For some other pollutants, awareness and an understanding, still currently incomplete, of their potential effects have developed only recently. These “emerging pollutants” include substances that have existed for some time, such as pharmaceuticals and personal care products, but also relatively new substances, such as nanomaterials. Their inclusion in routine monitoring programmes has so far been limited, making it difficult to robustly assess the risks to the environment and human health, and thus tojustify regulation and better monitoring. Targeted monitoring of selected emerging pollutants across the EU would be desirable to ensure timely awareness of potentially problematic substances that might need to be regulated. This monitoring should be supported by European research studies.

7. Could climate change influence the issue of hazardous substances in the aquatic environment ?

The question of hazardous substances in Europe’s fresh and marine waters is a complex issue, and climate change will add a further layer of complexity. In the absence of appropriately strong measures, this phenomenon is likely to adversely affect chemical water quality over the coming decades. In regions where more intense rainfall is expected, the frequency and severity of polluted urban storm flows is predicted to increase, whilst the flushing to water of agricultural pollutants, including pesticides and veterinary medicines, may be exacerbated.

Hotter, drier summers and increasingly severe and frequent droughts will deplete river flows, reducing contaminant dilution capacity and leading to elevated concentrations of hazardous substances. Rising water temperatures and other stressors associated with climate change may interact with hazardous substances to impact the immune system health of aquatic organisms.

Ocean acidification, driven by increasing atmospheric carbon dioxide (CO2 in water becomes carbonic acid), may change the speciation of metals in seawater and, therefore, their interaction with marine organisms. In addition, coastal erosion — likely to be also intensified by climate change — may lead to the exposure of historical landfill sites along the coastlines of Europe, releasing hazardous substances to their coastal waters.

8. Are there effective measures to further reduce the presence of hazardous substances in the aquatic environment ?

For many hazardous substances, information on industrial emissions to water must be reported under the European Pollutant Release and Transfer Register (E-PRTR). To date, however, reporting under E-PRTR is incomplete as to the spatial extent and temporal resolution of data describing emissions to water — markedly so, for some substances. It is important also to improve the quantitative understanding of the sources, emissions and pathways of all hazardous substances significantly. Advances in this area will facilitate the identification of appropriate measures to address chemical pollution of aquatic environments.

Whilst controls ‘at source’ are desirable, it is very likely that other measures to attenuate the emission of hazardous substances to water will remain essential, says the report. Such measures include advanced wastewater treatment, urban stormwater controls and specific agri-environmental practices such as riparian buffer strips. Reducing emissions of hazardous substances has been shown to yield economic and societal benefits.

A range of other measures can be implemented to reduce the emission of hazardous substances to water. It encompasses product substitution, restrictions on marketing and use, requirements to demonstrate the implementation of clean production processes and “best available techniques” (BAT) in applications for industrial permits, fiscal instruments, the setting of emissions and environmental quality standards, and action to raise public awareness.

To address these issues, recent European research studies have led to the development and testing of new assessment and modelling tools that help to link chemical contamination with observed deterioration of ecological quality. Such tools include approaches to evaluate existing chemical and biological monitoring data, together with site-specific experimental techniques to establish cause-effect relationships.

Indeed, it is not practical or affordable to sample and analyse at sufficient spatial and temporal resolution for hundreds of individual chemicals within fresh and marine waters, including aquatic biota and sediments. However, the focus upon a few pre‑selected priority substances bears a strong risk of missing other problematic substances. In addition, such an approach disregards the effects of chemical mixtures.

Further development of biological effects tools integrated with analytical chemistry is desirable and could contribute, in due course, to the identification of substances associated with risks. European research funds can play an important role in the further development of these tools.

9. Could chemicals be produced and used more sustainably ?

Efforts to promote a more sustainable consumption and production of chemicals are likely to require a mix of policy responses, including regulation, economic incentives, information-based instruments and a wider implementation of ‘green chemistry’ .  This would not only benefit Europe’s environment but also reduce the detrimental effects arising in other parts of the world as a result of the growing proportion of goods imported toEurope.

This approach involves developing new processes and technologies that maintain the quality of a product but reduce or eliminate the use and generation of hazardous substances. The adoption of sustainable, green chemistry techniques has been shown to generate financial benefits and hence provide competitive advantage. Currently, however, there is no comprehensive EU legislation on sustainable chemistry in place.

Reference : Aquatic environment: hazardous substances in Europe’s fresh and marine waters – An overview.  EEA Technical report No 8/2011. European Environment Agency Kongens Nytorv 6 1050 Copenhagen K Denmark Web: eea.europa.eu  Enquiries: eea.europa.eu/enquiries

 note : the GreenFacts “Highlights” are not peer reviewed by its Scientific Committee

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