Before revision: Daily avg (24-hour) Australia 8 25 25 50 China 35 75 70 150 European Union 25 40 50 PM: None; PM: 35 Hong Kong 35 75 50 100 PM: 9; PM: 9 Japan 15 35 100 South Korea 15 35 50 100 Taiwan 15 35 50 100 United States 9 35 150 PM: Not applicable; PM: 1 World Health Organization 5 15 15 45 Canada In Canada the standard for particulate matter is set nationally by the federal-provincial Canadian Council of Ministers of the Environment (CCME).
After revision: 3-4Daily avg (24-hour) Australia 8 25 25 50 China 35 75 70 150 European Union 25 40 50 PM: None; PM: 35 Hong Kong 35 75 50 100 PM: 9; PM: 9 Japan 15 35 100 South Korea 15 35 50 100 Taiwan 15 35 50 100 United States 9 35 150 PM: Not applicable; PM: 1 World Health Organization 5 15 15 45 Canada In Canada the standard for particulate matter is set nationally by the federal-provincial Canadian Council of Ministers of the Environment (CCME).