|
Total
PAHs were never detected at levels above the detection
limit in tissues from marine biota. A PAH congener,
Naphthalene was frequently detected at concentrations
above the detection limit. The lack of international
standards pertaining to Naphthalene contamination
prevents a more detailed evaluation of the Study's
baseline findings.
A
summary of the organic contaminants recorded in
biota tissues in the present Study and international
safety standards for human consumption is presented
in Table 5.2a. The values of organic contaminants
of concern recorded in this Study were always
below concentrations that either exceed international
safety standards or levels of concern to human
health.
| Table
5.2a Summary of Levels of DDT, TBT, PCB and
PAH Recorded in this Study and International
Safety Standards |
| Organic
Contaminant |
Highest
Concentration Recorded |
International
Safety Standard |
| Total
DDT |
56.2
ug kg-1 wet weight
(Gizzard Shad) |
5
ug g-1 wet weight1 |
| TBT |
33.0
ug kg-1 wet weight
(Mantis Shrimp) |
1
mg kg-1 wet weight2 |
| PCB |
25
ug kg-1 wet weight
(Mantis Shrimp) |
2
ug g-1 wet weight3 |
| PAH |
Naphthalene
was the only PAH recorded in tissues consistently.
42 ug kg-1 wet weight
(Gizzard Shad) |
No
action limits available in either the US or
Canada, although Naphthalene is a Class C
contaminant (ie possible human carcinogen)4 |
Note
1: USFDA (1990) criteria.
Note 2: This is equivalent to a safety factor
of 250 based on WHO safety margin criteria (based
on immune parameters) and assessed for fish consumption
(150 g day-1) and estimated daily intake of 2.5
ug kg-1
Note 3: USFDA (1990) criteria.
Note 4: USFDA (1989) criteria.
This
Study represents a baseline survey for sustainable
development in Hong Kong with regards to the marine
environment. As a key component of sustainable
development is to ensure that toxic substances
do not impair (eco)system functioning, this SUSDEV21
study provides a baseline for organic contaminants
of concern that can be used for comparative purposes
in the formulation of future marine environmental
management policies in Hong Kong.
|
|