TABLE 2.
AVERAGE POLLUTION IN 1996 (MEDIAN YEAR OF BIRTH),* COMPARED WITH VARIOUS AIR QUALITY STANDARDS
| Chicago | Houston | New York | Puerto Rico | SF Bay Area | All | EPA National Air Quality Standard | Cal EPA Air Quality Standard | WHO Air Quality Guidelines | |
|---|---|---|---|---|---|---|---|---|---|
| NO2, ppb (24-h ave) |
|
||||||||
| Mean (SD) |
26.9 (3.4) |
19.2 (4.6) |
32.1 (5.7) |
9.9 (2.9) |
18.9 (3.9) |
19.3 (8.0) |
53† |
30† |
20.9† |
| 25th percentile |
25.4 |
15.6 |
30.4 |
8.7 |
16.9 |
12.7 |
|
|
|
| 50th percentile |
27.0 |
19.4 |
32.4 |
9.0 |
18.7 |
18.7 |
|
|
|
| 75th percentile |
28.4 |
21.9 |
35.1 |
10.1 |
20.9 |
24.0 |
|
|
|
| O3, ppb (1-h max ave) |
|
|
|
|
|
|
|
|
|
| Mean (SD) |
34.8 (4.8) |
48.0 (5.0) |
35.6 (3.6) |
36.9 (9.2) |
32.0 (7.2) |
34.3 (7.7) |
NAS |
NAS |
NAS |
| 25th percentile |
31.9 |
44.8 |
33.6 |
28.8 |
26.3 |
29.1 |
|
|
|
| 50th percentile |
34.2 |
47.7 |
35.2 |
37.0 |
30.5 |
33.8 |
|
|
|
| 75th percentile |
36.6 |
51.5 |
36.9 |
45.9 |
36.5 |
37.5 |
|
|
|
| O3, ppb (8-h max ave) |
|
|
|
|
|
|
|
|
|
| Mean (SD) |
28.6 (4.0) |
38.1 (4.3) |
28.6 (3.2) |
30.2 (9.4) |
25.5 (6.4) |
27.6 (6.6) |
NAS |
NAS |
NAS |
| 25th percentile |
25.8 |
35.1 |
26.8 |
21.7 |
20.1 |
23.0 |
|
|
|
| 50th percentile |
28.3 |
38.0 |
28.0 |
30.3 |
24.6 |
27.3 |
|
|
|
| 75th percentile |
30.6 |
41.1 |
29.8 |
39.1 |
30.1 |
30.9 |
|
|
|
| PM10, μg/m3 (24-h ave) |
|
|
|
|
|
|
|
|
|
| Mean (SD) |
34.1 (4.5) |
30.1 (6.6) |
27.5 (4.1) |
29.1 (4.8) |
24.5 (5.5) |
27.8 (6.0) |
NAS |
20† |
20† |
| 25th percentile |
31.2 |
25.8 |
25.0 |
25.6 |
21.1 |
23.6 |
|
|
|
| 50th percentile |
33.8 |
29.3 |
27.1 |
28.4 |
23.48 |
27.1 |
|
|
|
| 75th percentile |
36.8 |
32.6 |
28.8 |
32.1 |
26.97 |
31.4 |
|
|
|
| PM2.5, μg/m3 (24-h ave) |
|
|
|
|
|
|
|
|
|
| Mean (SD) |
17.0 (1.6) |
13.2 (1.2) |
14.4 (2.0) |
8.1 (1.5) |
12.3 (1.5) |
11.8 (3.6) |
12‡ |
12† |
10† |
| 25th percentile |
16.1 |
12.3 |
14.2 |
7.2 |
11.3 |
8.5 |
|
|
|
| 50th percentile |
17.1 |
13.0 |
14.6 |
7.7 |
12.4 |
11.9 |
|
|
|
| 75th percentile |
18.0 |
12.9 |
15.4 |
9.1 |
12.8 |
14.5 |
|
|
|
| SO2, ppb (24-h ave) |
|
|
|
|
|
|
|
|
|
| Mean (SD) |
5.1 (1.2) |
3.6 (1.4) |
11.7 (3.3) |
4.1 (2.0) |
1.6 (0.9) |
4.0 (3.4) |
30† |
NAS |
3§ |
| 25th percentile |
4.6 |
2.7 |
10.1 |
2.9 |
1.3 |
1.6 |
|
|
|
| 50th percentile |
5.0 |
3.5 |
11.2 |
3.5 |
1.5 |
3.0 |
|
|
|
| 75th percentile | 5.5 | 4.4 | 14.0 | 4.8 | 1.9 | 5.0 | |||
Definition of abbreviations: ave = average; Cal EPA = California Environmental Protection Agency; EPA = U.S. Environmental Protection Agency; max = maximum; NAS = no annual standard; NO2 = nitrogen dioxide; O3 = ozone; PM2.5 = particulate matter < 2.5 μm in diameter; PM10 = particulate matter < 10 μm in diameter; ppb = parts per billion; SF = San Francisco; SO2 = sulfur dioxide; WHO = World Health Organization.
With the exception of PM2.5, where 2000 was used because of insufficient observations in 1996; reported as average (SD).
Annual mean.
Annual mean, over 3 years.
The WHO does not have an annual SO2 guideline because they regard their 7-ppb (20-μg/m3) 24-hour standard sufficiently protective for the annual average. In the GALA II regions, an annual average of about 3 ppb SO2 is comparable to a daily maximal concentration of 7 ppb.