The latest briefing released by the Public Health Communication Centre has looked into 36 odour pollution incidents across New Zealand, including Christchurch.
The incidents included the rancid smells that often waft across east Christchurch from the Bromley wastewater treatment plant after a fire there in November 2021 destroyed two filters.
In New Zealand, meat processing (33%), wastewater treatment plants (25%) and landfills (20%) were found to be the most common sources of odour pollution.
A case study from 2014 showed the seriousness of the health impacts, when 13 people in Eltham, Taranaki, reported to their GPs with odour-related symptoms after Fonterra discharged three million tonnes of buttermilk and 150,000 litres of raw milk into an anaerobic digesting pond that did not work.
The centre's research at the University of Otago (Wellington) showed prolonged exposure to odour pollution can make you sick, and suggested environmental controls do not go far enough to protect people’s health.
The briefing's lead researcher Dr Jonathan Jarman said he was surprised at how widespread the incidents were over the past 10 years, and found that it amounted to a significant public health problem in New Zealand.
"Things like prolonged stress, being unable to invite friends around, having to keep doors and windows closed in summer, and smells so bad that it made you want to vomit," he said.
His research identified other environmental odour pollution problems around the South Island, including the Green Island Landfill, the Mosgiel and Burnside animal rendering plants, the Tahuna wastewater treatment plant and the Victoria Flats Landfill near Queenstown.
‘‘You’ve actually got quite a few around the region.’’
He said the odour pollution from sites like these was often viewed as ‘‘an annoyance’’ for a small number of individuals, rather than a hazard that could make communities unwell.
Jarman said international research over the past 50 years had found prolonged exposure to foul smells could cause symptoms similar to those resulting from chemical poisoning, such as headaches, nausea, vomiting, cough, loss of appetite and insomnia.
Environmental regulators, namely regional councils like Environment Canterbury, were not taking foul odours as seriously as they should.
Jarman said they were overlooking the impacts when they only relied on indicators such as looking for toxic levels of chemicals in the air.
The briefing makes a number of recommendations, including calling for the National Public Health Service to proactively advocate for communities adversely affected.
Jarman said public health officers should talk to communities and encourage people to see GPs when they think they have symptoms relating to odour exposure.
He said he hoped public health could work with regional councils and industries - the source of the pollutants - to get problems resolved quickly.
The briefing also recommends GPs to notify all illnesses suspected to be caused by chemical contamination of the environment to their local Medical Officer of Health.
By RNZ and John Lewis, ODT
