I should like to keep to the wording I have used. They will be sent quickly, and I believe that they are complete. The lists will take into account any sound barriers that may be erected alongside the motorway.
Birmingham is already carrying out, on behalf of the Department of the Environment, a pilot scheme in another part of the city, and maps have been produced for that area. When the maps are passed over, we shall ask Birmingham to carry out a survey on each of the eligible dwellings so that a grant for insulation may be made. Our hope is that the survey will proceed quickly. Knowing as I do Birmingham City Council, which is working as our agent, I am sure that the work will proceed speedily.
Lead pollution is a matter for concern but not for alarm. It is necessary not to alarm people, although we express concern about the growth of the problem. Concern has been expressed by the Department since 1971 when the Chief Medical Officer sent a letter to all local medical officers of health on the subject of lead pollution. A great deal of work has been undertaken, but it is too soon to come to conclusions. The problem is new, as is the public's concern with the problem, and it is too early to produce valid scientific conclusions that will be useful to the House.
We have drawn some provisional conclusions on the subject of atmospheric lead. One conclusion has shown that the lead content is higher near motorways but that the concentration rapidly diminishes. There are also seasonal fluctuations which have to do with the prevailing wind.
I went myself to Birmingham to ensure that the work should have the degree of priority that it merits and to ensure that my officials and the Birmingham officials were talking the same language and using the same criteria. One result of those constructive talks was the establishment of a joint working party. I asked for its report in three to four weeks' time. That time is nearly up and I hope to have it soon. I am told that the working party has got down to work very well and is likely to produce information which will be useful to the local authority and the Government and will help the Government to make sensible decisions.
I said that although we should be concerned about the rate of growth of lead in the blood of people living near Spaghetti Junction, we should not be alarmist about it. There have been two measurements of people in this area between October 1972 and January 1974. Analysis of these shows that the increase was about four to five microgrammes of lead per 100 millilitres of whole blood. I have been asked the question, what is the danger level? I quite agree that that is the lay question which I also ask, because it is the question about which people concern themselves. There are people in parts of the country having quite naturally much higher levels of lead found in their blood than is yet the case at Spaghetti Junction.
To get this matter in proportion, I have been told that although the danger level cannot be rigorously defined—this is one of the things which concern me, because we do not absolutely know and cannot absolutely assure anyone—for industry, where this has been a problem much longer than it has among the general community, the following levels are given in the British medical Press. It regards up to 40 microgrammes as normal, between 40 and 80 as acceptable, between 80 and 120 as excessive and over 120 as being dangerous.
The levels we found at Spaghetti Junction were about 25 microgrammes, so they are well below danger and alarmist levels, from the information that we have. But I agree that the matter of concern is that the levels are rising at a rate of four to five microgrammes annually. For that reason alone the working party is justified, as is the raising of this matter. This problem will have to be kept under constant observation. The joint working party is getting on very well with its work.
Regarding lead in petrol generally, in 1972 the previous Government announced a voluntary programme to reduce the lead content of petrol from 0·84 grammes per litre down by stages to a limit of 0·45 by the end of 1975. The present limit is 0·64 grammes per litre. The second stage of this reduction programme was due by 1st January but unfortunately, because of the oil crisis, had to be postponed. However, my right hon. Friend the Secretary of State for the Environment will be considering very early indeed how that programme can be reinstituted. We want to go on by progressive stages if we can and we are proposing, as soon as the parliamentary timetable allows, to introduce legislation which will permit the Secretary of State to seek additional powers to control the amount of lead that is put into petrol and to do so by order.
One of our great difficulties—I must not mislead the House or the country—is that this is a very considerable cost on the balance of payments burden. If we eliminated lead from petrol, the probable cost would be about £300 million—at 1971 costs; thus it would be more today—for extra refining capacity, and an increased oil import requirement of 10 million tons a year, which would cost £400 million on the balance of payments deficit. So here we have a classic case of balancing the question of the economy against a more desirable environmental situation.
I do not entirely agree with my hon. Friend the Member for Perry Barr about experience in other countries. I understand that in Japan the lead content of petrol is a little below 0·4 grammes per litre—somewhat less than we expect to arrive at by 1975. The level which has been fixed is not fixed on health grounds, although it helps, but because it reduces the incidence of smog which is a special environmental circumstances there. In the United States present level are about twice as high as they are here, and although it is planned to reduce them shortly they will nevertheless be coming only to levels as much as we have at present here, and we regard those levels to be high and to need considerable reduction.
One hopes that we can make progress in other ways apart from the elimination of lead in petrol. Exhaust filters interest us. We may be able to filter the lead out of the exhaust, which would be, certainly from a balance-of-payments point of view, much more preferable. We have not made much progress there, but a commercial manufacturer has recently produced a filter for motor vehicle exhausts which is designed to trap particles of lead and the Department is sponsoring a comprehensive test programme to determine its effectiveness. If this filter is proved effective, we shall certainly be taking action on the matter as one other way of dealing with this problem.
I can, finally, assure the House that apart from the work around Gravelly Hill now initiated by the new joint working party established between the Government and Birmingham City Council, and other works taking place around the country—Fleet Street, for example, is being studied in great detail —we have a national network of sites where the Government and university workers are meeting to study the effect.