Environmental Engineering Reference
In-Depth Information
octyltin derivatives are essentially nontoxic as shown in Table 3 [13, 14, 18, 31]
and in Fig. 2 [13, 14]. With regard to the toxicity of a TBT salt, (
n
-Bu
3
SnCl) in
mammals, acute oral LD
50
values are in the range of 122-349 mg
kg (rats) as
shown in Table 3. Their biological activity is almost entirely due to the Bu
3
Sn
moiety, since in common with other trialkyltin compounds, the variation of the
inorganic substituent X does not usually have a significant effect on their toxi-
city.The“X”grouptendstoaffectpropertiessuchasvolatilityandsolubility.
The acute mammalian toxicities of the common triphenyltin (TPT) bio-
cides are generally very similar to, and often lower than those of their trib-
utyltin analogues. It is also interesting to note that anionic groups appear to
have an effect on the toxicity in these compounds as shown in Table 3.
Although TBT and TPT compounds are not unduly hazardous to hu-
mans, as discussed above, they are nevertheless very effective biocides against
a wide range of marine fouling organisms. Information on the activities of
various TBT and TPT derivatives against marine algae, barnacles, shrimps
and tubeworms has been published [13, 14].
Gadd [29] reported on some toxic effects of TBT compounds on microbial
processes. The inhibition of microbial processes by TBT has been recorded
for all major groups, with the main interactions occurring at cellular mem-
branes and chloroplasts, or the mitochondria in eukaryotes as shown in
Table 4 [32-36]. Maguire [37] and White et al. [22], also reported on toxicity
of TBT to organisms in detail.
/
Table 4
Some toxic effects of TBT compounds on microbial processes [32]
a
Process affected
Organism(s)
/
organelle(s)
Inhibitory concentration
(IC) (
µ
M)
Respiration
Bacteria
0.04-1.7
Photosynthesis
Cyanobacteira
∼
1(IC
50
)
Nitrogen fixation
Anabaena cylindrica
<
1(IC
50
)
Primary productivity
Microalgae
0.00055-0.0017
Growth
Microalgae
0.00017-0.0084
Energy-linked reactions
Escherichia coli
0.15-
>
50 (IC
50
)
Aureobasidium pullulans
Growth
27 (IC
50
)
Growth
/
metabolism
Fungi
0.28-3.3
Bacteria
0.33-16
Photophosphorylation
Chloroplasts
0.56-5
and ATP synthesis
H
+
-ATPase activity
Neurospora crassa
plasma membrane
0.06 (IC
50
)
mitochondrial
0.01 (IC
50
)
vacuolar
0.6 (IC
50
)
a
Gadd [29] compiled with data from original sources cited in publication from [30-33]
