§ Mr. Corrieasked the Secretary of State for Scotland what is the outcome of the study commissioned by him into the background levels of polychlorinated-biphenyls and their derivatives in soil; and if he will make a statement.
§ Mr. AncramSamples of soil have been taken on a 20 km grid from 36 locations between Girvan in the south-west and Stonehaven in the north-east. These samples have been analysed by the laboratory of the Government chemist for polychlorinated-biphenyls, polychlorodibenzo-p-dioxins and polychloro-dibenzo-furans.
Only four of the samples show a polychlorinated-biphenyl content above the limit of detection. The highest result, 100 parts per billion, is not exceptional having regard to the normal background levels in soils generally.
Few of the results for dioxins and furans are above the limit of detection, except for tetrachloro-dibenzo-furan, where most of the results are in the range of 0.01–0.06 parts per billion. Two results, of 0.1 and 0.4 parts per billion, have been found in samples from locations near Girvan and Coylton in Ayrshire. I have asked that further samples be taken from these locations for analysis.
The United Kingdom does not set a limit for dioxin levels; it is however of interest to note that the United States centre for disease control has set a limit of 1.0 parts 216W per billion in soil for the most toxic of the dioxins, 2378 tetrachloro-dibenzo-dioxin, in soil. None of the results obtained exceeds a hundredth of that figure.