Taranaki's top public health doctor says the smells coming from an industrial composting works do not have to be toxic to impact on neighbours' health.
Remediation New Zealand's site at Urutī. Photo: screenshot
Since 2001 Remediation New Zealand has received commercial waste, including oil and gas drilling cuttings and fluids, and poultry farm waste at its composting and worm-farming site at Urutī.
Last year Taranaki Regional Council refused to renew Remediation NZ's consents, but the company appealed the decision and meanwhile keeps operating at the rural site northeast of New Plymouth.
A coalition of four Urutī community groups are one of the objectors to the company's appeal in the Environment Court.
The region's medical officer of health, Dr Jonathan Jarman, told the court people exposed to offensive odours often report health impacts they believe are related to the smell.
He said the offensive smell hitting residents in Urutī was not thought to be a toxic substance, but studies worldwide had shown bad smells could still harm health.
"Through poorly understood psychosocial mechanisms you end up with health effects which are almost identical to the chemicals operating above the irritant threshold - the health outcomes for that group of people are actually the same [as toxic exposure]."
Jarman said he had taken many factors into account; whether the company followed best practice, its record in previous Environment Court and regional council reports, the number and nature of the complaints, and the nature of the effects.
He determined it was likely Remediation NZ's composting stink caused the ill-health.
"Given the inherent uncertainty about odours and health effects I have to be honest and say I have only a medium level of certainty."
Jarman said the response of the company could affect psychosocial responses.
"The industry creating the odour is on a spectrum somewhere between indifferent to aggressive denial.
"If you have an industry that is starting to say it's going to fix the odour, and they still remain in aggressive denial, then I find the community does not change in its assessment of the odour and… the odour has to go if you want that community to get better."
Local authorities and health officials could also influence complaints.
"People become sensitised, they become annoyed, it starts to impact on their lives and then it leads to some people complaining," Jarman said.
"Complaints vary depending on how likely it is that the agency they're complaining to is going to take any action."
Occupational and environmental medicine specialist Dr David Black is a witness for Remediation New Zealand.
Black stressed that no toxic substance had been detected in the Urutī neighbourhood and whatever was there was unmeasurable.
He said the health impacts were technically psychosomatic.
"Some people find that to be an offensive term because they say 'it's not real, it's all in the head' - that's completely unfair. What psychosomatic means is that psychological inputs are resulting in physical illness, which can happen."
He said social permission could influence some people otherwise not inclined to complain.
"There will be people who would not complain, but if someone else does complain they might be sort've given permission to complain. So sometimes you can get a bit of a movement going," Black said.
"That's just the nature of communities - it might be a good thing it might not be."
Local Democracy Reporting is Public Interest Journalism funded through NZ On Air