The 3d follow-up report on the 15 Air Pollution Pilot Study recommendations is to concentrate on the status of North Atlantic Council, NATO/Committee on the Challenges of Modern Society Recommendations 1 through 8 in cities with populations over 600,000 in 1977. It also can be compared to responses to the 1975 and 1976 surveys and follow-up reports to evaluate changes in air pollution activities in the past 2 years. The Recommendations include general assessment of air pollution, standard-setting, establishment of air quality monitoring systems and suitable systems and suitable systems for retrieval and storage of data, employment of recognized reference methods for monitoring and institution of uniform procedures for conducting emissions inventories.