All are indicators for air pollution, except -: (A) CO, (B) SO2, (C) Soiling Index, (D) Smoke index
Answer is A. Indicators of air pollution: Smoke (soiling) index Sulphur dioxide Grit and dust measurement Coefficient of Haze Air pollution index CO is not an index! Park's Textbook of Preventive and Social Medicine, 25th edition, Page No.796