An assessment of the challenge presented by copper in the UK natural environment: a joint analysis by the Hazardous Substances Advisory Committee (HSAC) and the Expert Committee on Pesticides (ECP)

Copper is a natural component of the earth’s crust, rivers and oceans. However, its many desirable properties mean that copper is mined, smelted and used in a range of industrial and domestic applications. It also has applications in agriculture including use as a fungicide. Although a certain level of copper is vital as a micronutrient for many species, in excess it is toxic to aquatic and terrestrial wildlife. Environmental monitoring data show that levels in UK rivers have declined since the 1980s, possibly due to reductions in emissions from industry and the transport sector. However, it is still at levels of some concern and it remains as one of the highest ranked toxic metals in our rivers. Unlike rivers, there is less evidence for a decline in soils and indeed it may be increasing in some circumstances. Because of the presence of natural chemicals in the environment capable of binding freely available copper in less-toxic forms , assessing environmental risks is not straightforward. Fortunately, scientifically derived biotic ligand models can help predict the freely available copper and hence real world environmental risks. From the data available, the relative risks to wildlife from current copper levels in aquatic, marine and terrestrial ecosystems are high. This would suggest that applications which lead to additional emission, such as in fungicides, should not be encouraged. This report has been produced by members of Defra’s HSAC and ECP committees. It does not claim to be either an exhaustive or authoritative review. However, the information presented should be adequate as an introduction to the UK situation with regards to copper in the environment.