Copper and cadmium: inflow to the North Sea, 1990-2001

The inflow of copper to the North Sea increased in the early 1990s. In recent years, there has not been any clear trend for the inflow of copper and cadmium.

		1990	1996	1997	1998	1999	2000	2001
		1 000 kg
Copper		359	455	458	450	560	494	658
of which	Rivers	187	328	260	301	373	314	472
	Dredging sludge	165	97	197	119	157	151	156
	Other sources	6.5	29	1.5	30	30	29	30
Cadmium		10.7	12.6	11.6	17.3	18.7	13.5	19.5
of which	Rivers	5.5	9.2	5.2	13	13.8	7.4	13.7
	Dredging sludge	4.0	3.2	6.4	4.2	4.9	5.9	5.7
	Other sources	1.2	0.2	0	0	0	0.2	0.1
Source: RIKZ.							RIVM/EDC/Oct03

Inflow of copper and cadmium to the North Sea

The inflow of copper to the North Sea increased between 1990 and 1996. At the end of the 1990s, it looked as though the inflow was stabilising but there has not been any clear trend over the last three years. Nor is there any clear trend for the inflow of cadmium.
The annual fluctuations are mostly accounted for by annual variations in river flows.

Policy relating to concentrations of copper and cadmium

Government policy is geared towards reducing concentrations of toxic substances to the desired quality standard. In order to achieve this aim, emissions of many substances need to be reduced. A reduction of 50% in the levels of copper in surface water was required between 1985 and 1995. The required reduction for cadmium was 70%. These objectives have been more than met (V&W 1998).

Relevance

Cadmium is a heavy metal that is toxic for almost all organisms. Copper is an essential metal. In other words, excessively low concentrations have a negative effect on organisms, but excessively high concentrations are toxic.

References

• RIKZ, monitoringsprogramma Rijkswaterstaat.
• V&W (1998). Rijn- en Noordzeeactieplan: Industriële emissies naar het oppervlaktewater 1985 - 1995. FWVO-nota, nummer 98.02.

Relevant sections and indicators in the Environmental Data Compendium

• Copper and cadmium in suspended matter in brackish surface water, 1989-2001 (page is not available yet)
• Emissions into water in the Netherlands, 1990-2001
• Emissions to water by target sector in the Netherlands, 2001
• Surface water quality: Policy
• Guide to Environmental theme of Toxic and hazardous substances

Relevant information outside of the Environmental Data Compendium

• More information about the inflow of substances to the North Sea can be obtained from the RIKZ (National Institute for Coastal and Marine Management).