Environmental Engineering Reference
In-Depth Information
2.2
Sea Nine 211
Sea Nine 211 exhibits acute toxicity to phytoplankton at concentrations
of 0.0139-0.032 mg L
-1
, to crustacean species at concentrations of 0.0047-
1.312 mg L
-1
,tobivalvesataconcentrationof0.85mgL
-1
,andtofishspecies
at concentrations of 0.0027-0.0205 mg L
-1
(Table1).Fromthesedata,itcanbe
concluded that this compound exhibits weaker acute toxicity to bivalves than
to other aquatic organisms such as phytoplankton and fish etc. On the basis of
these acute toxicity values, it is classified as “very toxic-toxic” according to the
OECD guidelines.
Data on the chronic toxicities of Sea Nine 211 to
Daphnia magna
and
sheepshead minnow are reported to be 0.0012 mg L
-1
and 0.006 mg L
-1
[26],
respectively (Table 2). The 28-day LC
50
to rainbow trout larva is 0.014
mg L
-1
[26], leading to fears that the chronic toxicity of Sea Nine 211 is
equivalent to that of other antifouling compounds.
2.3
ZnPT and CuPT
As summarized in Table 1, the published literature contains very little data
on the acute toxicity of ZnPT and CuPT to aquatic organisms. The re-
spective toxicity values are reported to be 0.028 mg L
-1
for phytoplank-
ton, 0.029-0.034 mg L
-1
for
Daphnia magna
,and0.0026-0.4 mg L
-1
for
fish species. On the other hand, CuPT exhibits acute toxicity to phyto-
plankton growth, immobilization of
Daphnia magna
,andthesurvivalof
fish species at concentrations of 0.0028-0.035 mg L
-1
, 0.022 mg L
-1
,and
0.0043-0.011 mg L
-1
, respectively. Although the obtained toxicity data are
limited, CuPT tends to exhibit greater acute toxicity to fish species than ZnPT.
Evaluated on the basis of the OECD classification guidelines, the toxicological
data on ZnPT and CuPT correspond to the “very toxic” definition, suggesting
that both compounds are highly toxic to aquatic organisms.
ZnPT has significant effects on the embryogenesis of fish species, and an
early life-stage toxicological study in which fertilized eggs were exposed to
ZnPT, has confirmed deformities in the spinal curvature of fish larva after
hatching [27]. Meanwhile, Okamura et al. [26] obtained 28-day LC
50
values of
0.0046 mg L
-1
and 0.0013 mg L
-1
for ZnPT and CuPT, respectively, in a study
using rainbow trout larva (Table 2). These toxicity values concern that both
compounds may exhibit high chronic toxicity to fish species.
ZnPT and CuPT are degraded to pyridine sulfonic acid in the aquatic envi-
ronments[28].AsshowninTable 1,the120 hLC
50
to freshwater algae, 48 hEC
50
to
Daphnia magna
and 96 hLC
50
to fish species was 28.9 mg L
-1
,
>
122 mg L
-1
and 57.1 -
>
127 mg L
-1
, respectively. Acute toxicities of pyridine sulfonic acid
were weaker than the parent compounds, ZnPT and CuPT. These results suggest
that toxicities of ZnPT and CuPT decrease in the process of degradation.
