§ Mr. Strangasked the Secretary of State for Scotland when, over the last 10 years, surveys have been conducted of the concentrations of copper, chromium, cadmium, zinc, lead, nickel, mercury, arsenic, boron, organo-chlorine compounds and PCBs in sediments and sea water around the coast of Harris or other parts of the Outer Hebrides; by whom the surveys were conducted; and what were the results.
§ Mr. John MacKayThere have been no specific surveys of sea water around the Outer Hebrides in the last 10 years. However, a survey in western Scottish coastal waters undertaken by Department of Agriculture and Fisheries for Scotland scientists in 1984 showed typical concentrations as follows:
- Copper 0.1–0.2/ugl -1
- Cadmium 10–15 ngl -1
- Lead 10–15 ngl -1
The cadmium and copper values agree with samples taken in a recent survey off the Scottish west coast by a German vessel, which produced nickel concentrations of some 0.18–0.22/ugl -1.
There are no recent reliable data for chromium, zinc, mercury or arsenic, but older data suggest concentrations of zinc of 1–3/ugl -1 and mercury of less than 1 ngl -1.
No information is available about concentrations of organo-chlorines or PCBs in that area.
Boron is not generally considered to be a contaminent as it is relatively abundant in sea water.