Environmental Engineering Reference
In-Depth Information
Concentrations of Irgarol vary with season; higher concentrations recorded
in marinas and boatyards outside the boating season are attributed to mainte-
nance of vessels—scrubbing and repainting activities—and at the beginning
of the season elevated concentrations coincide with the introduction of newly
antifouled boats to the water [52].
No correlations have been found between dissolved Irgarol 1051 concen-
trations and pH, temperature or salinity [52].
2.2
Diuron
Diuron has also been detected in saline coastal waters at concentrations
higher than in freshwaters, suggesting that its use in antifouling products may
be of significance [30, 62-64]. It has been detected in the UK, Sweden, Spain,
the Netherlands, Portugal and Japan [31]. As with Irgarol, concentrations of
diuron in water vary depending on the boating season [62].
The impact of the agricultural uses of diuron has been demonstrated in the
detection of herbicide residues in water samples from draining streams and
pumping stations of the agricultural area of Thessaloniki, Greece. Consider-
able amounts of diuron were found to be released from the agricultural fields
and transferred through rivers, draining streams and pumping stations to the
coast [65]. In the UK, Environment Agency data demonstrate that one of the
pesticides which most frequently exceeds the environmental quality standard
of 1 mg L
-1
in controlled waters is diuron, predominantly owing to its use as
a herbicide in agriculture [30].
2.3
Chlorothalonil
Occurrence of chlorothalonil does not follow the same pattern as that of
many other biocides [31]. It can be present in high concentrations in early
spring—before the boating season—and this may be attributed to agricul-
tural use of the compound on adjacent land [41]. Other studies have shown
the absence of chlorothalonil in some marinas [49, 63], which may be due
to its rapid degradation in water: biodegradation is apparent after 4 weeks
and proceeds faster in seawater supplemented by cultured marine bac-
teria [48].
2.4
Dichlofluanid
Dichlofluanid has been detected in Greece [66] and Spain [67]. In the UK it
has not been detected in water [41], and it has been reported as being absent
from Mediterranean marinas [49].
