Geoscience Reference
In-Depth Information
Table 10.4
Action levels (mg kg
−
1
dry weight) for metals in sediments in the USA, Canada, Hong Kong, ICES Working Group on
Marine Sediments (ICES WGMS) and for England and Wales. (ICES, International Council for Exploration of the Sea; ERL, Effects Range
Low; TEL, Threshold Effects Level; ERM, Effect Range Median; PEL, Probable Effect Level; ISQV, Interim Sediment Quality Value).
(From CEFAS 2003.)
Metal
Ecotoxicological standards
Chemistry (mainly)
NOAA
Canada
Hong Kong
ICES WGMS
England and Wales existing guidelines
guidelines
range of values
(approximate value)
ERL
TEL
ISQV-low
Action Level 1
As
8.2
7.24
8.2
20-80
20
Cd
1.2
0.676
1.5
0.5-2.5
0.4
Cr
81
52.3
80
60-300
40
Cu
34
18.7
65
20-150
40
Hg
0.15
0.13
0.28
0.1-1
0.3
Ni
20.9
15.9
40
37-130
20
Pb
46.7
30.2
75
30-120
50
Zn
150
124
200
160-700
130
ERM
PEL
ISQV-high
Action Level 2
As
70
41.6
70
50-1000
50-100
Cd
9.6
4.21
9.6
2.4-12.5
5
Cr
370
160
370
180-5000
400
Cu
270
108
270
90-1500
400
Hg
0.71
0.7
1
0.8-5
3
Ni
51.6
42.8
-
45-1500
200
Pb
218
112
218
100-1500
500
Zn
410
271
410
500-10000
800
to determine temporal trends rather than test
for compliance, and that the aim is for no deter-
ioration in sediment quality. There are other
approaches being assessed in some countries,
such as the 'Added Risk' approach, where back-
ground concentrations are determined and a
toxicological quotient is added to derive a
maximum permissible concentration. For those
contaminated sediments deemed unsuitable for
conventional disposal, they may be confined, con-
tained, treated or simply not dredged.
information on the relevant shelf sedimentary
processes. Given the complexities of monitoring
sediment transport processes, this can be expen-
sive. Increasingly, real-time or near real-time data
are broadly available on the main oceanographic
parameters, through outputs from regional mon-
itoring programmes (e.g. in the USA, European
waters and the Great Barrier Reef shelf ). It is
also sensible to obtain data across spatial scales
sufficiently broad to assess the driving forces
Table 10.5
Canadian Environmental Protection Agency
(CEPA) Lower Action Levels (from Disposal at Sea Regulations)
for selected chemicals in sediments (in mg kg
−
1
dry weight)
(London Convention 2005).
10.4.7 Design of research and monitoring
programmes
There is a very wide range of advice documents
available (mostly on the web) regarding various
human activities on the shelf that have sedi-
mentary impacts, and there are a suite of general
themes that should be considered in designing
research and monitoring for shelf sedimentary
systems. It is clearly important to monitor at
frequencies and with accuracies that will reveal
Chemical
Current level
Cadmium
0.6
Mercury
0.75
Total PCBs
0.1
Total PAHs
2.5
PCB, polychlorinated biphenyls; PAH, polycyclic aromatic
hydrocarbon.
