With the permission of the Ceann Comhairle, I propose to take Questions Nos. 1 and 2 together. The monitoring of air pollution by local authorities to total emissions to the atmosphere from all sources and separate figures on vehicular pollutants are not available. The monitoring of emissions from individual vehicles for toxicity is not feasible, but the present law provides specifically against emission of excessive smoke, which may be detected and made the subject of court action. Furthermore, the EEC directive on road worthiness tests for heavy vehicles, the implementation of which is being prepared at present, provides for a check on smoke emission. I may add that emissions from diesel engines, which are generally used on the heavier vehicles, are considered to have a lower toxic content than those from petrol engines. I have previously indicated that on grounds of practicality and cost, I do not propose to require re-location of exhaust pipes as suggested.