ATMOSPHERIC CHEMISTRY 121
TABLE 3
Recommended ambient air-quality limits for selected gases throughout the world.
Country CO (ppm) SO 2 (ppm) O 3 (ppm) NO 2 (ppm) PM 10 (g/m^3 )WHO 26 (1 hr) 0.048 (24 hr) 0.061 (8 hr) 0.105 (1 hr)
8.7 (8 hr) 0.019 (annual) 0.021 (annual)
EU 8.7 (8 hr) 0.132 (1 hr, 24x) 0.061 (8 hr) 0.105 (1 hr, 18x) 50 (24 hr, 35x)
0.047 (24 hr, 3x) (25x/yr, 3 yr avg.) 0.021 (annual) 40 (annual)
0.008 (annual)
UK 10 (8 hr) 0.132 (1 hr, 24x) 0.050 (8 hr) 0.105 (1 hr, 18x) 50 (24 hr, 35x)
0.047 (24 hr, 3x) 0.021 (annual) 40 (annual)
0.008 (annual)
Russia 4.4 (24 hr) 0.02 (24 hr) 0.045 (24 hr)
Australia 9 (8 hr) 0.20 (1 hr) 0.10 (1 hr) 0.12 (1 hr) 50 (24 hr, 5x)
0.08 (24 hr) 0.08 (4hr) 0.03 (annual)
0.02 (annual)
New Zealand 9 (8 hr, 9x) 0.132 (1 hr, 9x) 0.08 (1 hr) 0.105 (1 hr, 9x) 50 (24 hr, 5x)
China 9 (1 hr) 0.19 (1 hr) 0.10 (1 hr) 0.13 (1 hr) 150 (24 hr)
3.5 (24 hr) 0.06 (24 hr) 0.06 (24 hr) 100 (annual)
0.02 (annual) 0.04 (annual)
Japan 20 (8 hr) 0.10 (1 hr) 0.06 (1 hr) 0.04–0.06 (24 hr) 200 (1 hr)
10 (24 hr) 0.04 (annual) 100 (24 hr)
Hong Kong 26 (1 hr, 3x) 0.30 (1 hr, 3x) 0.12 (1 hr, 3x) 0.16 (1 hr, 3x) 180 (24 hr)
9 (8 hr) 0.13 (24 hr) 0.08 (24 hr) 55 (annual)
0.03 (annual) 0.04 (annual)
Thailand 30 (1 hr) 0.30 (1 hr) 0.10 (1 hr) 0.17 (1 hr) 120 (24 hr)
9 (8 hr) 0.12 (24 hr) 50 (annual)
0.04 (annual)
Philippines 30 (1 hr) 0.06 (24 hr) 0.08 (24 hr) 150 (24 hr)
9 (8 hr) 0.023 (annual) 60 (annual)
Nepal 9 (8 hr) 0.027 (24 hr) 0.042 (24 hr) 120 (24 hr)
0.02 (annual) 0.021 (annual)
Bangladesh 0.03 (annual) 0.04 (annual) 200 (annual)
India 3.5 (1 hr) 0.03 (24 hr) 0.04 (24 hr) 100 (24 hr)
(Residential) 1.7 (8 hr) 0.023 (annual) 0.03 (annual) 60 (annual)
Saudi Arabia 35 (1 hr, 2x/30) 0.28 (1 hr, 2x/30) 0.15 (1 hr, 2x/30) 0.35 (1 hr, 2x/30) 340 (PM15 24 hr)
9 (8 hr, 2x/30) 0.14 (24hr) 0.05 (annual) 80 (PM15 annual)
0.03 (annual)
Egypt 26 (1 hr) 0.13 (1 hr) 0.10 (1 hr) 0.20 (1 hr) 70 (24 hr)
9 (8 hr) 0.06 (24 hr) 0.06 (8 hr) 0.08 (24 hr)
0.02 (annual)
South Africa 0.30 (1 hr) 0.12 (1 hr) 0.20 (1 hr) 180 (24 hr)
0.10 (24 hr) 0.10 (24 hr) 60 (annual)
0.03 (annual) 0.05 (annual)
Canada 0.065 (8 hr) 30 (PM2.5 24 hr)
Mexico 11 (8 hr) 0.13 (24 hr) 0.11 (1 hr) 0.21 (1 hr) 150 (24 hr)
0.03 (annual) 50 (annual)
Brazil 35 (1 hr) 0.14 (24 hr) 0.17 (1 hr) 150 (24 hr)
9 (8 hr) 0.03 (annual) 0.08 (1 hr) 0.05 (annual) 50 (annual)
Source: Data was collected from Web sites from the individual countries and organizations.
Note: Numbers in parentheses represent the averaging time period and number of exceedances allowed.C001_008_r03.indd 121C001_008_r03.indd 121 11/18/2005 10:15:19 AM11/18/2005 10:15:19 AM