Water quality and pollution by hazardous substances

Numerous hazardous substances deriving from our use of chemical substances are found in the aquatic environment. The most widespread contamination of the aquatic environment is from pesticides and pesticide residues. Our wastewater contains many hazardous substances derived from detergents and other substances we flush into the sewers. In addition, many substances are used in industrial production and in the transport sector.

Numerous organic pollutants are found in groundwater, including pesticides and substances leaching from contaminated sites. Pesticides also occur in watercourses. Concern is being expressed about hormone-like substances, which can change the sexual characteristics of fish species, such as roach. In coastal waters, it has become apparent that hazardous substances, such as the antifouling agent TBT, can affect marine organisms (see Epaedia: Late lessons from marine anti-fouling paints).

Source: EEA

Personal-care products such as soaps, shampoos and different types of cosmetic products contain substances that are not degraded in sewage treatment systems and can therefore reach the environment. Many substances are persistent, lipophilic (capable of combining with or dissolving in fats) and bio-accumulating.

Triclosan is an antimicrobially active substance used for many purposes such as disinfectants, preservatives and personal-care products. Triclosan is transformed to methyltriclosan in the environment through a path which is not fully understood. This substance persists in the environment and accumulates in organisms.

Methyltriclosan concentrations in fish are increasing at all sampling sites in Germany, but data about the toxicity and action of methyltriclosan are largely missing.

See Epaedia on Wildlife early warning signs

Publications and links

EEA 2005: The European environment - State and outlook 2005. Part A: Integrated assessment, chapter 5 Freshwaters, and 6 Marine and coastal environment

EEA 2003: Europe's water: An indicator-based assessment. Topic report No 1 

Further information on pollution of the marine environment with hazardous substances can be found in Epaedia: Impact of pollution and intervention