This report deals with the implementation of Article 10 of the Directive on air quality limit values and guide values for sulphur dioxide and suspended particulates (80/779/EEC). For this purpose the Commission, in cooperation with the Member States, has prepared a 'Common Measurement Programme' which basically provides for: (i) examination and improvement of the reference measurement methods, (ii) examination of the comparability of the measuring procedures and equipment used for monitoring purposes in the Member States, (iii) the provision of guidelines and the carrying out of measurements to determine the corresponding stringency of the limit values laid down in Annexes IV and I of the Directive.