Environmental Engineering Reference
In-Depth Information
Table 2
Chronic toxicity of alternative antifouling biocides to aquatic organisms
Aquatic
Endpoint
Chronic toxicity
Refs.
ZnPT
a
CuPT
b
PK
c
Sea Nine 211
d
(mg L
-1
)(mgL
-1
)(mgL
-1
)(mgL
-1
)
organisms
Crustacean
Daphnia
21 day
0.0012
[23]
magna
chronic EC
50
Fish
Cyprinodon
early life NOEC
0.006
[23]
variegatus
Oncorhynchus
7dayLC
50
0.0084
0.0076
0.140
0.014
[26]
tshawytcha
14 day LC
50
0.0056
0.003
0.084
0.014
21 day LC
50
0.0049
0.0017
0.061
0.014
28 day LC
50
0.0046
0.0013
0.042
0.014
a
bis-(1-Hydroxy-2(1H)-pyridinethionate-O,S)zine
b
bis-(1-Hydroxy-2(1H)-pyridinethionate-O,S)copper
c
Pyridinetriphenylboron
d
4,5-Dichloro-2-n-octyl-3-isothiazolone (Sea Nine 211)
2.4
PK
PK is a new chemical substance that has been developed in recent years for
use as a biocide in antifouling paints. Consequently, there are almost no re-
ports on the harmful effects of this compound on aquatic organisms. As
shown in Table 1, the only data that has been reported concerns its acute
toxicity to phytoplankton, prawns, and red sea bream. The 72 hEC
50
to
Skele-
tonema costatum
,the96 hLC
50
to prawns, and the 96 hLC
50
to red sea bream,
are reported to be 0.00215 mg L
-1
, 0.149 mg L
-1
,and0.242 mg L
-1
,respec-
tively. Although the acute toxicity of PK is weaker than that of ZnPT and
CuPT, it is classified as “very toxic” according to the OECD toxicity guidelines.
The 28-day LC
50
of PK was found to be 0.042 mg L
-1
based on a 28-
day rearing experiment using rainbow trout larvae carried out by Okamura
et al. [26]. This value is equivalent to that of ZnPT and CuPT. These results
cause great concern regarding the harmful effect of this compound on aquatic
organisms.
2.5
Irgarol 1051
The acute toxicity of Irgarol 1051 and its degradation product 2-methylthio-
4-
t
-butylamino-6-amino-
s
-triazine (M1) to various aquatic organisms are
