Environmental Engineering Reference
In-Depth Information
All animals contained butyltins with varying degrees in different tissues with
butyltins ranging from 0.02 up to 10.2 mg kg
-1
(wet wt). As with other biota,
a decreasing contamination from coastal waters to the open seas was ob-
served. Butyltins in the liver of Steller sea lion from Alaska were much lower
(19 ng g
-1
) than those from Japan (150-220 ng g
-1
) [117]. Even in deep-sea
fish [16], TBT levels of up to 175 ng g
-1
(wet wt) were comparable to coastal
fish. Moreover, phenyltins, particularly TPT, occurring up to 1430 ng
g, are
much higher in shallow-water organisms. This confirms the long-range trans-
port of TBT and TPT to the deep-sea.
Using archived biological samples,
time trends
of the pollution in the
1980s and 1990s were assessed. Decreasing levels of butyltins were found in
water and mussels in Japan after regulation in 1990 [63]. This trend has,
however, not been observed in open waters in tuna [75]. In Germany, concen-
tration of TBT in North Sea and Baltic Sea organisms remained relatively con-
stant during the period of 1985-1999, whereas levels of TPT decreased [98].
TBT concentrations remained at 17 ng g
-1
for mussels, reflecting that TBT is
still used despite the ban in 1990 for small boats in Germany. TBT levels in
bivalve molluscs from the east and west coasts of the USA have been found to
decrease systematically at some sites and remain static or fluctuating at others
in the 1988-1990 national status and trends mussel watch project [118].
In
freshwaters
, zebra mussels (
Dreissena polymorpha
)showhighbioac-
cumulation with little toxicity. We found that in lake harbors all organisms
contained butyl- and phenyltins to variable levels,
D. polymorpha
showed
highest values, which were related to water contamination [14, 28]. After
regulation of TBT-antifouling paints a significant decrease was noted [19].
Transformation products of TBT occurred in only low proportions, which
also holds for TPT indicating slow transformation. The ubiquitous presence
of butyl- and phenyltins was also demonstrated in various biota of other
lakes [80]. The concentrations of TBT and TPT ranged from 0.0015-28.2 and
0.081-7.28
/
gg
-1
(dry wt), respectively.
The occurrence of TBT and TPT is also widespread in
marine seafood
[91]
and human exposure may take place via this route [91, 119]. In Japan, TBT
and TPT levels were 0.02-1.3 and 0.03-1.3
µ
gg
-1
, respectively [120]. Typical
TBT and phenyltin residues in fish were in the range of 0.05-0.3
µ
gg
-1
[81].
Edible mussels, clams and squids contained TBT in the range of 10-100
µ
gg
-
.
Fish reared in nets treated with antifouling paints contained very high TBT
concentrations of 1.5
µ
gg
-1
[121]. TBT and TPT concentrations in fish mus-
cle ranged between
<
0.12-6.10 and 0.13-7.91
µ
gg
-1
(dry wt), respectively. In
µ
gg
-1
in
whole fish occurred. In Canada marine fish fillets contained low levels of TBT
(
<
1-2 ng g
-1
) and molluscs between
<
1-156 ng g
-1
. Increased TBT levels
were found in fish from aquaculture such as salmon (4-3.1
gg
-1
TBT in muscle tissue [14], and up to 0.49
freshwater fish 0.2
µ
µ
gg
-1
). Salmon
from American public fish markets contained TBT of 0.08-0.2
µ
gg
-1
[122].
The levels are, however, not considered to be harmful to humans, as they
µ
