Auckland Regional Public Health Service has placed conditions on a proposed pest control programme in the Hunua Ranges to protect public health.
Auckland Council is conducting an aerial 1080 bait operation from late August onwards this spring. Sodium fluoroactetate (1080) will be applied by helicopter to 30,501 hectares of parkland in the Hunua Ranges. This will include the Waharau and Whakatiwai regional parks; Department of Conservation (DoC) administered lands, including the Mataitai Conservation Area, and some adjoining private land.
The purpose of the operation is to significantly reduce pest numbers and maintain the natural habitat of the Hunua Ranges. Pest levels have risen again after the highly successful 2015 operation.
The Hunua Ranges is a source of approximately 65% of Auckland’s drinking water and houses four large water reservoirs. There are also risks to neighbours and many visitors to the parks to be considered.
Auckland Regional Public Health Service (ARPHS) has a regulatory role in approving Auckland Council’s aerial 1080 operation application, with any conditions thought necessary to protect the health of the public. ARPHS has worked closely with Council and Watercare to ensure that conditions protect neighbours, park visitors and the drinking water reservoirs from contamination with 1080.
Measures to protect people include closing the park while 1080 is being aerially applied by helicopter, and until track clearances have been completed, depending on rainfall conditions. More track clearances will be completed if there has been insufficient rainfall to cause bait disintegration.
Water reservoirs will be protected by having:
ARPHS’ Medical Officer of Health will be notified of all water testing results that occur following the 1080 drop. ARPHS has a regulatory role of ensuring that the drinking water supply remains safe in accordance with the Drinkingwater Standards for New Zealand, and will not approve reconnection unless water testing results show that the concentration of 1080 in water is undetectable.
The greatest potential risk from 1080 is to a young child who may come across a bait pellet and put it into their mouth. The risk of poisoning is also increased by a child’s low body weight and relatively high metabolic rate.
To reduce this risk, the park will be closed while bait is being dropped and this will be followed by track clearances. The number of track clearances required will be determined by track usage and weather, particularly rain and wind.
Depending on the dose, symptoms of 1080 poisoning when ingested may occur within 30 minutes of exposure and progress rapidly. Lower doses may take up to three hours to produce symptoms. Symptoms may include abdominal pain and vomiting, rapid breathing, irritability or agitation, and may progress to confusion, collapse, seizures, and unconsciousness.
People with suspected 1080 poisoning must seek emergency hospital medical treatment immediately. Any remaining material suspected of being contaminated with 1080 should be collected and taken with the patient to hospital.
Any suspected case of 1080 poisoning must be referred to ARPHS’ Medical Officer of Health by the attending doctor, as per the requirements of the Health Act 1956, and the Hazardous Substances and New Organisms Act 1996. The Medical Officer of Health will investigate how the poisoning may have occurred, ensure contaminated items are collected for testing, and require remedial action.