Chloronitrotoluenes
Entry in the marine environment
Chloronitrotoluenes are used in the manufacture
of dyestuffs, herbicides and fine chemicals, such
as chlorotoluidines or dichlorobenzaldehyde. They
are not manufactured in large quantities in the
EC (Jerman and Young 1992)
Chloronitrotoluenes (CNTs) are mainly used as intermediates
and diffuse release into the environment is unlikely.
Point source contamination, apart from accidental
spillage of chemicals, will be confined to effluent
discharges from factories involved in CNT production
and use. Consequently, releases into the marine
environment are likely to be limited.
Recorded levels in the marine
environment
No information on concentrations of CNTs in the
marine environment could be located.
Fate and behaviour in the marine
environment
Jerman and Young (1992) found limited information
on the fate and behaviour of CNTs. It was concluded
that some limited biodegradation may occur. However,
volatilisation could be significant and therefore
CNTs were not expected to be persistent in the water
column. There was also the potential for CNTs to
be moderately adsorbed to sediment and suspended
solids.
Effects on the marine environment
Toxicity to marine organisms
An exhaustive literature review on the toxicity
of CNTs to marine organisms has not been carried
out for the purposes of this profile. The information
provided in this section is taken from existing
review documents (Jerman and Young 1992). The most
sensitive groups of organisms have been identified.
Jerman and Young (1992) found toxicity data for
saltwater life limited to one study, a microtox
assay. Therefore, their assessment was based on
the toxicity to freshwater life. Again, freshwater
data were limited, but CNTs appear to be of moderate
to low toxicity to aquatic life, with algae, invertebrates
and fish exhibiting similar sensitivities.
Bioaccumulation
Estimations of bioaccumulation suggested that moderate
bioaccumulation could occur, but further data were
required to make a proper asessment of bioaccumulation
potential.
Potential effects on interest
features of European marine sites
Potential effects include:
- potential toxicity to algae, invertebrates and
fish at concentrations above the EQS of 10 µg
l-1 (annual average) and 100 microg
l-1 (maximum allowable concentration)
in the water column;
- given the uncertainty over bioaccumulation,
confirmation that bioaccumulation is not occurring
should be sought where CNTs are found in the water
column;
- some potential for accumulation in sediments
and therefore a potential hazard to sediment-dwelling
organisms.
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References
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