Biodegradation in Water

Page No. Source Quotes from Decision Documents
349 11 Agency App. C “Data gaps..biodegradation in aquatic systems and in soils at varying pH, soil type and temperature”
350 3 Agency App. C “The Agency sought an independent expert review of the degradation of 1080 in water and soil” (review was of 17 papers provided by ERMA, none on degradation in soil or water under field conditions)
352 2 Agency App. C “No standard guideline studies were submitted by the applicants on the aquatic fate and degradation of 1080 and none were located by the Agency other than on the hydrolysis of 1080”
352 3 Agency App. C “1080 is stable to hydrolysis in the absence of microorganisms”
353 1 Agency App. C “In 1994 the Auckland Regional Council commissioned analysis of 8 water samples for the presence of micro-organisms capable of degrading 1080..two of the water samples had the capacity to defluorinate 1080..no defluorinating activity was found over a period of 4 weeks in the remaining samples”
354 1 Agency App. C “non-standard, non [Good Laboratory Practice]…A brief summary only of the test results [on aquatic plant uptake of 1080] was reported..test conditions not specified..weight basis for concentration in plants not specified, no statistical analyses reported, [plant species studied not reported]..no information provided on effects on..aquatic invertebrates in the test aquaria..Eason et al., 1993”
354 3 Agency App. C “distilled water control..no statistical analyses reported”
354 4 Agency App. C “non-standard, non [Good Laboratory Practice], [one] distilled water control..no statistical analyses reported, 21°C otherwise test conditions not specified, degradation results presented graphically only””
354 5 Agency App. C “1080 below limits of detection [at 21 oC in aquaria with plants, bacteria and fungi, dosed with 0.1mg 1080/L] after 141 hours, the longer time to degrade was attributed to the absence of Pseudomonas spp.”
354 6 Agency App. C “the fluoride ion was monitored [in a study of degradation of 0.1mg/L 1080 in water]..reaching..0.75mg/L”
354 7 Agency App. C “[the fluoride ion concentration was]..stated as being closely correlated with biodegradation of 1080 but data not provided [Parfitt et al, 1994]”
356 1 Agency App. C “Between 24 and 48 hours the concentration [of 1080] in the warmer water had declined significantly compared to that at 11oC. ..no 1080 could be detected in the warmer water after 141 hours, but [approx.] 30% of the initial dose was still present in the cooler water”
359 1 Agency App. C “[definition of rapidly degradable] at least 70% of the substance can be degraded biotically or abiotically, in the aquatic environment within 28 days”
359 2 Agency App. C “The lack of data [on aquatic degradation] from a standard test method…makes the assessment of the rate of degradation more complex..”
359 3 Agency App. C “The Agency sought an independent expert opinion on the degradation of 1080 in water”
359 4 Agency App. C “The half-lives of 1080 in [aquatic] laboratory studies were in the range <<1 to 8 days”
359 5 Agency App. C “Overall, the relevance of the aquatic plant/water studies to the degradation of 1080 in water in NZ is not clear”
360 2 Agency App. C “the Agency was not able to locate, any data on the aquatic toxicity of the metabolite fluorocitrate in water or soil”
447 4 Agency App. C “In the rabbit control experiment, very low levels of fluoroacetate were detected at 3 of the 4 [water monitoring] sites”
455 1 Agency App. C “There are some references within the sources provided which could be obtained and reviewed, although it is unlikely they will change the overall conclusions”
434 1 Agency App. C: Fisk “[Peter Fisk Associates was asked to] provide a review of a number of sources [17 papers] describing the behaviour of the monofluoroacetate ion in the environment” (16 papers were lab studies)
435 1 Agency App. C: Fisk “The pathway and rate [of uptake by organisms] would need to be considered in order to determine whether such a process is important in determining the assessment of overall persistence”
438 1 Agency App. C: Fisk “there was little degradation in the distilled water aquarium”
438 2 Agency App. C: Fisk “Information on the metabolic fate could not be assessed, as..metabolites were not tested for [in Eason study on 1080 degradation in aquaria]”
439 1 Agency App. C: Fisk “1080 is hydrolysed very slowly in water at neutral pH in the absence of biota..at ambient temperatures the half-life would be expected to be at least 4 years”
439 2 Agency App. C: Fisk “a Pseudomonas species was isolated from river sediment by a process of an enrichment culture technique that could utilise fluoroacetate as the sole carbon source”
440 1 Agency App. C: Fisk “It is not possible to say how important this is [a culture of a Pseudomonas species was found to contain an enzyme that could catalyse the hydrolysis of fluoroacetate] as it is not an eco-toxological paper”
440 3 Agency App. C: Fisk “fluoride was produced in tandem with the disappearance of the substance [1080, in a flask culture with a bacterium]”
443 1 Agency App. C: Fisk “Samples of soil and water were taken from 8 localities in (presumably) New Zealand..there are no data in the report on the type or localities..or prior history..in 3 [out of 8 soil samples] and 2 (out of 8) water samples it was possible to culture..bacteria..that could use 1080..1080-utilising bacteria were either absent in the other samples or were not viable under the conditions used for enrichment”
444 1 Agency App. C: Fisk “Initial dosing [in an aquatic degradation study] was 0.12 mg/L (120 ppb) 1080, which was stated to be 40x the highest environmental water found in the field”
444 2 Agency App. C: Fisk “there was a marked lag phase, probably indicating the induction of a population of 1080 utilising micro-organisms…at 7°C [the DT 50] was ca. 10 days [in stream water dosed with 0.12mg/L 1080]”
445 1 Agency App. C: Fisk “Comment [by Fisk] This is an important paper that demonstrates that [1080] is degraded quite rapidly by plants and micro-organisms under laboratory conditions” (one study, one aquatic plant species, one dose rate of 1080)
445 2 Agency App. C: Fisk “at 11°C the concentration of 1080 [in aquaria with a species of aquatic plant] declined..at 192 hours there was still 23% of the [1080 dosed at 0.12 mg/L] remaining”
445 4 Agency App. C: Fisk “Conclusion [by Fisk]: [1080] is rapidly metabolised..by.. aquatic plants” (single study of one plant species, one dose rate)
447 6 Agency App. C: Fisk “The one criticism is that soils and water used in the degradation studies could have been subject to prior exposure to fluoroacetate”
452 1 Agency App. C: Fisk “There was no elimination of [1080] in the absence of [aquatic] plant material”
453 2 Agency App. C: Fisk “The rate of elimination [of 1080 in water with aquatic plants] was positively related with temperature and was significantly lower at 5 oC and 11°C”
453 4 Agency App. C: Fisk “There are no data as to whether the metabolic compounds are fluorocitrate (toxic) or glycolate (non-toxic) or any other potential product of metabolism [study on removal of 1080 from water by plants]”
453 1 Agency App. C: Fisk “One trial gave faster rates of elimination..and was ignored”
454 1 Agency App. C: Fisk “[Fisk conclusion][1080 is] rapidly biodegradable in natural waters and soils, although this is very temperature dependent..degradation is also much slower in soils with lower moisture content” (based on only 1 field study on water and none on soil)
454 4 Agency App. C: Fisk “[Fisk conclusion] These enzymes [that catalyse defluorination] are present in soil bacteria and fungi”
454 6 Agency App. C: Fisk “[Fisk conclusion] It is possible that plants may metabolise [1080] to fluorocitrate”
457 1 Ag. App. C: Sample storage “no further work has been undertaken to more fully investigate factors potentially affecting degradation of 1080 in soil during frozen sample storage [at -20°C] e.g. Soil type, water content, microbial population, and from there identify the most valid procedures for storage and processing samples..in the light of the findings by O’Halloran & Jones (2003) [1080] present in some samples..may have been degraded during storage at -20°C to present undetectable concentrations at analysis.”
109 1 Applicants’ references “Looking for microorganisms that degrade 1080 in 8 soil and 8 water samples. Three soils and 2 water samples did contain the required bacteria” (Lloyd & McQueen, 1998)
14 4 Committee Decision “In wet environments 1080 residues disappear in one to four weeks”
59 1 Committee Decision “the available scientific data on the degradation of 1080 in water indicate the substance is biodegradable but that there is still some uncertainty regarding the relevance of some of the test data to the New Zealand environment”
60 3 Committee Decision “the Committee does recommend further research on the degradation rates of 1080 in water”
71 1 Committee Decision “the applicants..clarified that the breakdown of 1080 in the aquatic environment would be better described as dilution”
71 4 Committee Decision “Contamination of animals via consumption of stock water is considered very unlikely due to the low concentrations and rapid degradation of 1080 in waterways”
158 2 Decision App. A “the documentation provided with 1080 must include..its expected soil or water degradation rate”