By Chloe Ranford, Local Democracy Reporter.
New Zealand's largest wine region will begin researching if pesticides negatively affect air quality in rural areas.
The Marlborough District Council plans to trial a new air monitoring programme within a year to better understand the "localised impacts" of farm chemicals, like spray drifts.
It comes 13 years after a consultant hired by the council suggested it begin tracking air pollution near schools and residential areas in Blenheim, concerned that airborne "agrichemicals" impacted human and environmental health.
Blenheim was the only location in Marlborough to currently see its air quality monitored by the council, with pollutants traced back to dust, pollen, salt, heating or running vehicles.
Council environmental science and monitoring manager Alan Johnson said the new programme would help fill in the blanks around how farming activities impacted air pollution.
Johnson said agrichemicals that drifted from vineyards during spraying – known as "spray drift" – might be captured by the new rural air programme, but were not its sole focus.
"This monitoring is not designed to 'track' individual instances of spray drift, but looks to try and understand whether these rural activities are having an effect," he said.
To start with, the council would look for sulphur to indicate signs of other agrichemicals. Sulphur was sprayed on vineyards to control fungal diseases and clean winery tanks.
Results from the programme would allow the council to better manage risks and decide if more action was needed.
Currently, agrichemicals were not regulated under New Zealand's air quality laws. The council would instead look to California's Department of Pesticide Regulation, which used a strict programme to evaluate and control pesticide use.
A paper tabled at an environment committee meeting earlier this month said the council had received advice on setting up the programme, and aimed to start trials within the year.
The trials would be paid for by a $19,000 grant.
The council declined to release the advice, written by Licoln Agritech, ahead of its next environment committee meeting on November 19, when it would be presented to councillors.
Setting up the new air programme was flagged a priority in the council's long-term plan due to "community expectations".
Pesticides and their potential cancer-causing effects were a common submission point during the council's annual plans.
Data provided by the Ministry of Health from the years 2014 to 2016 showed Nelson Marlborough had slightly lower rates of cancer registration and deaths than the national average.
Blenheim resident Marion Preston said pesticides, blown over from the three vineyards beside her home, often caused her skin to "itch and burn".
"They spray for a week at a time ... They usually start in October, but started this year in September because everything was ahead. Every October is headache month."
Sustainable Winegrowing New Zealand had guidelines to avoid spray drift, such as spraying in good weather conditions and being aware of neighbours and waterways.
But just one of Preston's neighbours warned her before spraying – the same one to avoid spraying in high winds.
She hoped results from the new programme were made public.
Wine Marlborough general manager Marcus Pickens said board members thought vineyards had left behind the "poor spray drift operations" that might have occurred in the past.
"It's in no-one's interests to spray when it's windy ... Not only because the product is not reaching the target, but because of perception issues, and doing the right thing," Pickens said.
The council's new air monitoring programme could prove that there were good spray drift practices in place, he said.
Results released from a study last year uncovered the herbicide terbuthylazine, used to kill weeds in vineyards, in two Marlborough wells – one of which supplied water to residents – but neither breached drinking water standards.
The study also tested wells for vineyard weedkiller glyphosate but none of the wells returned positive results.
New Zealand Winegrowers general manager of sustainability Edwin Massey said the industry had no data on spray drift.
"[The new air monitoring programme] is really interesting to me. I look forward to the results to inform us on our current practices and whether we can improve on them," he said.
He said members were currently sent a "agrichemical rule book" each year. It listed each agrichemical and their potential impacts on the environment or human health, so vineyards understood what to avoid.
The most common chemicals used in Marlborough were fungicides to kill powdery mildew, insecticides to kill mealybugs and herbicides to target competing weeds.
Vortex Marine and Outdoors owner Pete Watson, who raised concerns about vineyard spraying during an unsuccessful run for council last year, said the new programme was "fantastic news".
"It would be especially welcome on the outskirts of Blenheim, in places like Fairhall School or Rapaura School. Those schools sit right amongst the vineyards," he said.