§ Mr. Ellis Smithasked the Parliamentary Secretary for Science if he will set out in tabular form in the OFFICIAL REPORT the total tonnage per square mile of insoluble deposit, soluble deposit and total solids resulting from air pollution at stations where measurements are taken for the average of three years prior to the Clean Air Act becoming law; what was the same average for the three years since the present Act became law for Bournemouth, Eastbourne, Penzance, Trafford Park, Manchester, Phillips Park, Heaton Park, Stoke-on-Trent, Salford, Stockport, Warrington, Burnley, Eccles, Bolton, and Widnes; and at which three places in the country the measurements were highest and lowest.
§ Mr. Denzil FreethAnnual records of atmospheric pollution are maintained in terms of years ending on 31st March. The period of three years most nearly ending with the Clean Air Act becoming law is that ending on 31st March, 1957. During this period, the average of the annual mean of the recordings at all sites where deposit gauges were in operation are as follows expressed in tons per square mile:
Undissolved Deposit Dissolved Deposit Total Deposit 10.4 7.8 18.2 Figures for the individual sites—773 in 1955; 892 in 1956; 993 in 1957—from which these averages were obtained appear in the 28th, 29th and 30th Reports in the series entitled "The Investi- 30W gation of Atmospheric Pollution", published by Her Majesty's Stationery Office.
For the three year period ending 31st March, 1960, the same averages in tons per square mile for sites in the places detailed in the second part of the Question are as follows:
— Undissolved Deposit Dissolved Deposit Total Deposit Bournemouth No readings before February, 1959 Eastbourne No readings available Penzanne No readings available Trafford Park 1 site 33.9 8.9 42.8 Manchester Average of 6 sites 7.0 6.6 13.6 Phillips Park 1 site 15.5 9.9 25.4 Heaton Park 1 site 6.2 6.1 12.3 Stoke-on-Trent Average of 14 sites 11.3 6.3 17.6 Salford Average of 4 sites 14.4 6.4 20.8 Stockport Average of 3 sites 12.0 7.7 19.7 Warrington Average of 5 sites 10.5 10.8 21.3 Burnley 1 site 5.0 7.7 12.7 Eccles Average of 2 sites 10.7 7.0 17.7 Bolton Average of 7 sites 6.7 8.0 14.7 Widnes Average of 6 sites 10.8 20.3 9.5 The three places in the country at which the measurements averaged over the three year period ending 31st March, 31W 1960, were highest and lowest are as follows:
— Undissolved Deposit Dissolved Deposit Total Deposit Highest 1 Mountain Ash (Glamorgan) Belasis Avenue Billingham (Co. Durham) Belasis Avenue Billingham (Co. Durham) 2 Holmewood (Derbyshire) West Thurrock (Essex) Mountain Ash (Glamorgan) 3 Easton Yorkshire) Nelson Avenue Billingham (Co. Durham) Holmewood (Derbyshire) Lowest 1 Boghead (Lanarkshire) Tulliallan (Fife) Loch Katrine (Perthshire) 2 Loch Katrine (Perthshire) Saline (Fife) Glencorse Reservoir (Edinburgh) 3 Brixham (Devon) Clackmannan Boghead (Lanarkshire) It is now well known that deposited matter is not representative of, nor the most dangerous part of, air pollution. In addition, deposited matter falls near to the source of origin so that measurements at an individual site are representative of a restricted local area and not of a township.