Environmental Engineering Reference
In-Depth Information
TABLE 23.13
DPM Exposure Margins (Ratio of Occupational ÷ Environmental Exposures)
Exposure Margin
Ratio — Average
Environmental
Exposure
for 0.8
μ
g/m
3
of
Environmental
Exposure
b
Exposure Margin
Ratio — Average
Environmental
Exposure
for 4.0
μ
g/m
3
of
Environmental
Exposure
b
Estimated Occupational
Exposure/Concentration
Environmental Equivalent
a
Occupational
Group
public transit
workers
15-98 µg/m
3
3-21 µg/m
3
4-26
0.8-5
U.S. railroad
workers
39-191 µg/m
3
8-40 µg/m
3
10-50
2-10
Fork lift operators
7-403 µg/m
3
1-85 µg/m
3
2-106
0.37-21
High-end boundary
estimate
1200 µg/m
3
252 µg/m
3
315
63
Source:
U.S. Environmental Protection Agency (EPA), Health assessment document for diesel engine
exhaust, Report No.: EPA/600/8 - 90/057F, National center for Environment Assessment,
Washington, DC, 2002, Table 8.1
a
Equivalent environmental exposure = occupational exposure × 0.21 (See Chapter 2, Section 2.4.3.1);
some values are rounded.
b
0.8 μg/m
3
= average 1990 nationwide on-road exposure estimate from HAPEM model; the companion
rural estimate is 0.5 μg/m
3
, and 0.4 μg/m
3
is a high-end estimate. The 1996 nationwide average is
0.7 μg/m
3
, the companion rural estimate is 0.2 μg/m
3
, however, a high-end estimate is not available for
1996. See Chapter 2, Sections 2.4.3.2.1 and 2.4.3.2.2.
5000
0.4
Weekly mortality
SO
2
4000
0.3
3000
0.2
2000
0.1
1000
0
0
Oct. 18 Nov. 1 Nov. 15 Nov. 29 Dec. 13 Dec. 27 Jan. 10 Jan. 24 Feb. 7
Feb.21 Mar. 7 Mar. 21
1952
1953
Week ending
FIGURE 23.23
Relationship between London fog pollution measured as SO
2
between December 5 and
9, 1952, and mortality. Note that mortality remained elevated through February 1953. Average SO
2
during
the time of the fog was 0.57 ppm (24 h U.S. NAAQS for SO
2
= 0.03 ppm). (From Bell, M.L. and Davis, D.L.,
Environ. Health Perspect
., 109(Suppl. 3), 389, 2001.)
Search WWH ::
Custom Search