Hazardous substances in fresh and marine water can harm aquatic life and pose a risk to human health, according to a new report published by the European Environment Agency (EEA).

The report notes that while European legislation to address the issue is relatively strong, new challenges exist including ‘emerging pollutants’ where potential effects are not yet fully understood. More effort is also needed to ensure that chemicals are produced and used more sustainably.

Hazardous substances are emitted to fresh and marine waters through a range of pathways and from a variety of sources, including industry, agriculture, transport, mining and waste disposal, as well as from homes.

Hazardous substances found in fresh and marine waters and associated sediment and biota include a wide range of industrial and household chemicals, metals, pesticides and pharmaceuticals. Some substances, for example tributyltin (TBT), persist in aquatic environments long after they have been phased out.

The substances can have detrimental effects on aquatic biota. Substances with endocrine-disrupting properties, for example, can impair reproduction in fish and shellfish, while the effects of organochlorines on marine life are well documented.

Humans can be exposed to hazardous substances in water, through ingesting contaminated drinking water and consuming contaminated freshwater fish and seafood. Some metals have been found in seafood above regulatory levels, whilst levels of banned substances such as DDT can also be high.

Legislation is in place but faces new challenges

The report says that well-established legislation within Europe has led to positive outcomes including a reduction in emissions of metals to air and water. Legislation implemented more recently, including the Water Framework Directive and REACH (Regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals) will play a key role in addressing hazardous substances in water.

However, the report flags up incomplete scientific understanding of pollutants where an awareness of potential effects has only emerged recently.

These ‘emerging pollutants’ include substances that have existed for some time, such as pharmaceuticals and personal care products, but also relatively new ones such as nanomaterials.

The report says that policy makers need more information on the levels and effects of the emerging pollutants and a better understanding with regard to the effects of chemical mixtures which are found in the more polluted water bodies of Europe.

Climate change will damage chemical water quality

In the absence of appropriately strong measures, climate change is likely to adversely affect chemical water quality over the coming decades. More intense rainfall, for example, is predicted to increase the flushing of hazardous substances from both urban and agricultural land.

The report concludes that to reduce hazardous substances in water, a more sustainable production and use of chemicals should be applied both in Europe and beyond.

The Agency says a global approach would not only benefit Europe's environment but also reduce detrimental effects arising in other parts of the world, because a growing proportion of goods consumed within Europe are produced outside its borders.

Adopting sustainable green chemistry techniques could also play an important role, although there is currently no comprehensive EU legislation in this area.

Download the report in full here