Dr Belinda Cridge: 1080 scepticism still an issue

1080 is an important pest control tool, says scientist Dr Belinda Cridge

Dr Belinda Cridge, from Otago University's Department of Pharmacology and Toxicology, does not believe that all who oppose the use of 1080 are well informed. Nor, however, does she expect an end to public scepticism any time soon, because of its history of use in New Zealand.

"This creates many issues that are not able to be resolved by scientific evidence alone," she said.

Ongoing concerns appeared to revolve around the impact of 1080 on non-target species and water contamination. Common concerns in terms of non-target mortality centred on native species, such as birds and fish, and hunted species, such as deer and pigs.

We understand the mechanism of toxicity of 1080 fairly well, and New Zealand scientists, in particular, have done a lot of work on the toxicity and environmental fate of this compound over many years.

Dr Belinda Cridge, Otago University

"There is debate about how many of these deaths are directly caused by 1080 exposure, as compared to other causes," Dr Cridge said.

"1080 is toxic to all species (actually everything is toxic if you are exposed to enough of it, so 1080 isn't novel in this regard). However, birds and reptiles seem to have a degree of tolerance. In contrast, mammals are very susceptible to 1080 toxicity, so in New Zealand, where all mammals, except sea lions and a bat species, are introduced, 1080 is an important pest control tool.

"The other concerns are around 1080 leaching into waterways and causing a range of effects to wildlife and humans. Scientifically, the understanding is that the original 1080 compound is broken down quickly in the environment and doesn't persist in the environment or water, like many other toxins. This makes it unlikely that it will accumulate in waterways and cause down-stream poisonings."

Scientific work on 1080 had slowed, as most recent research efforts had focused on finding alternatives, but many people would be aware that New Zealand was "fairly unique" in its large-scale use of 1080.

"This is because we are in the privileged position of having few native mammals. Therefore, we are uniquely placed to use 1080 in pest control," she said.

"Since 2014 only 400 articles on 1080 have been published in scientific journals worldwide.

"Many of these are case studies of poisonings (1080 is used in other countries, just not to the same scale) or studies that are referring to 1080 in comparison to other toxins.

"We understand the mechanism of toxicity of 1080 fairly well, and New Zealand scientists, in particular, have done a lot of work on the toxicity and environmental fate of this compound over many years.

"From my own interests, I would like to understand more about how 1080 is detoxified in the body, as this may give us clues as to why dogs and kea have a unique sensitivity to the compound. But this is because this is my area of expertise. I think overall we actually have a very good handle on what the toxin does and at what doses.

"Developments in targeted application using GPS have improved the overall safety of the compound, as it is much less likely to be found in non-target areas. These types of technological advances are (very) important for the ongoing use of 1080, and to improve its overall use and safety."

* Dr Cridge declared she was bidding for funding to develop alternatives to 1080 for pest-control in New Zealand.