Emerging contaminants in groundwater - NERC Open Research ...

OR/11/013
Table 4.6 Common metabolites identified by this study and by Sinclair (2010)
Compound This study Sinclair
Chlorothalonil
2-amido-3,5,6-trichlo-4cyanobenzenesulphonic
acid
3-carbamyl-2,4,5-trichlorobenzoic
acid
Diflufenican 2-(3-trifluoromethylphenoxy)
nicotinic acid (AE B107137)
Florasulam 5-(aminosulfonyl)-1H-1,2,4triazole-3-carboxylic
acid
N-(2,6-difluorophenyl)-8-fluoro-5hydroxy[1,2,4]triazolo[1,5-c]
pyrimidine-2-sulfonamide
Flufenacet FOE oxalate FOE oxalate
Iodosulfuronmethyl-sodium
FOE sulphonic acid thiadone
2-amino-4-methoxy-6-methyl-
1,3,5-triazine
23
2-amido-3,5,6-trichloro-4cyanobenzenesulphonic
acid (R417888)
3-carbamyl-2,4,5-trichlorobenzoic acid (3carboxy,
2,5,6-trichlorobenzamide)
(R611965, SDS46851)
2-(3-trifluoromethylphenoxy) nicotinamide
(AE 0542291)
5-hydroxy-XDE-570 (5-hydroxyflorasulam)
AE F145740
metsulfuron-methyl
Metaldehyde Acetaldehyde acetaldehyde
Metsulfuronmethyl
Saccharin 2-(aminosulfonyl) benzoic acid (IN-D5119)
methyl 2-(aminosulfonyl) benzoate (IN-
D5803)
4.4.3 Corroborating evidence for assessment
There have been some studies of pesticide metabolites in groundwater, these have tended to
be in areas where the suite of applications differs from that currently used in the UK (Chang
and Liao, 2002; Fava et al., 2005; Giacomazzi and Cochet, 2004; Hildebrandt et al., 2007;
Kolpin et al., 2004).
Glyphosate is now the most widely used herbicide in the world, with dramatic increases in
agricultural use since the introduction of glyphosate resistant crops. Microbial degradation
produces aminomethyl phosphonic acid (AMPA) (Kolpin et al., 2000) and it has been
anticipated that AMPA may be problematic. The high water solubility of both the parent and
the metabolite has meant that their analysis has been difficult. Although AMPA has a DT50 of
about 151 days and is therefore persistent it also has a relatively high Koc of 8087 and would
not be classified as vulnerable to leaching by the simple method described above.
Similarly for parent compounds which have non-agricultural applications, there will be routes
to groundwater which would not be identified, such as routes which do not pass through the
soil zone. Kolpin (2006) showed AMPA to be detected in wastewater-impacted surface
waters about four times as frequently as the parent.