Water samples taken at the Hokitika Township water intake following an Animal Health Board aerial possum control operation have all come back clear of 1080. The samples were extracted by an independent company and analysed by Landcare Research.
The first two samples were taken within 24 hours of the completion of the Kokatahi aerial bovine TB control operations. A further sample was taken 48 hours after the operation with the final sample taken immediately after heavy rain at the weekend.
“Unsurprisingly, no 1080 residue was found in any of the water samples tested,” says Imogen Squires, AHB West Coast-Tasman Community Relations Advisor.
“Over the past 20 years, more than 2500 water samples have been tested by Landcare Research after aerial 1080 operations. Not a single sample taken from drinking water supply contained any trace of 1080. The Hokitika water intake was excluded from the aerial operation, and the use of advanced GPS technology allows our contractors to stick to extremely accurate flight paths and avoid precise exclusion zones.”
The Ministry of Health’s provisional maximum acceptable value (PMAV) for 1080 in drinking water is 3.5 parts per billion (ppb). PMAV is the level that is not considered to cause significant risk over a lifetime of consumption. At this concentration, a 60kg person would need to drink 120,000 litres of water in one sitting to receive a lethal dose. Scientific evidence shows that 1080 is rapidly metabolised and excreted and does not accumulate in the body.
As a further precaution, the Ministry recommends water should not be used for human consumption until tests show 1080 concentration is less than 2ppb. No 1080 was detected in any of the samples taken after the Kokatahi operation, which had a test sensitivity of >0.1ppb.
While opponents of 1080 continue to claim that the toxin’s use to control possums, rats and stoats poses a threat to drinking water and freshwater ecology, there is now a strong body of accepted science showing that this is not the case. In 2011, the Parliamentary Commissioner for the Environment – an impartial parliamentary watchdog – released a detailed report on the use of 1080 in New Zealand, recommending more not less needed to be used to have any hope of reversing the serious decline in native biodiversity. The report draws on dozens of published scientific papers showing that the current use of 1080 is both safe and necessary. It can be downloaded from the PCE website www.pce.parliament.nz.