Table 1 |
|||||||
|
Calculated spatial extent from illustrative case study under differing assumptions and definitions |
|||||||
|
Factor under study |
Emission rate (μg/m·s) |
Background concentration (μg/m3) |
Meteorological conditions |
Definition of spatial extent |
Estimated spatial extent (m) |
||
|
|
|||||||
|
Wind speed (m/s) |
Stability class |
Comparison method |
Threshold |
||||
|
|
|||||||
|
Spatial extent definition |
5 |
0 |
4 |
D |
Absolute |
0.25 μg/m3 |
70 |
|
5 |
0 |
4 |
D |
Absolute |
0.1 μg/m3 |
190 |
|
|
5 |
0 |
4 |
D |
Absolute |
0.05 μg/m3 |
430 |
|
|
5 |
0 |
4 |
D |
Relative |
50% of reference |
60 |
|
|
5 |
0 |
4 |
D |
Relative |
20% of reference |
170 |
|
|
5 |
0 |
4 |
D |
Relative |
10% of reference |
380 |
|
|
Emission rate |
2.5 |
0 |
4 |
D |
Absolute |
0.1 μg/m3 |
90 |
|
10 |
0 |
4 |
D |
Absolute |
0.1 μg/m3 |
430 |
|
|
Background concentration |
5 |
0.25 |
4 |
D |
Relative |
50% of reference |
120 |
|
5 |
1 |
4 |
D |
Relative |
50% of reference |
N/A |
|
|
Meteorological factor |
5 |
0 |
3 |
F |
Absolute |
0.25 μg/m3 |
350 |
|
5 |
0 |
2 |
B |
Absolute |
0.25 μg/m3 |
70 |
|
|
5 |
0 |
6 |
D |
Absolute |
0.25 μg/m3 |
40 |
|
|
Health risk threshold |
5 |
0 |
4 |
D |
Absolute |
20 per million cancer risk |
300 |
|
5 |
0 |
4 |
D |
Absolute |
1 per million cancer risk |
> 500 (beyond domain) |
|
|
|
|||||||
|
Zhou and Levy BMC Public Health 2007 7:89 doi:10.1186/1471-2458-7-89 |
|||||||
