Hazardous Substances

Substances which accumulate in the environment and impact on wildlife are considered to be hazardous. Substances identified as a particular cause for concern include cadmium, mercury, lead, pesticides, polychlorinated biphenyls ( PCBs), polycyclic aromatic hydrocarbons ( PAHs) and brominated flame retardants ( PBDEs).

Hazardous substances are released to the environment as a result of human activities such as manufacturing, pest control and the burning of fossil fuels. Trace metals may also be released naturally by leaching from rocks and soils. Although the use of some substances has been banned (PCBs and some brominated flame retardants) they continue to be present in the environment as a result of historical use.

The marine environment is the ultimate sink for these substances through direct introduction from marine activities such as dredge spoil dumping, transport via rivers or deposition from the atmosphere by solution at the surface or in rainfall. Inputs of selected substances to the marine environment via rivers and effluent discharges have been quantified for the OSPAR Rivers and Direct Discharges ( RID) programme since 1990.