By JOHN COUSINS
A controversial, highly toxic chemical banned in at least three countries and linked to delayed adolescence in boys will be sprayed on Bay sports grounds to kill worms.
The spray Thiodan, whose active ingredient endosulfan is a neurotoxic insecticide, will be sprayed on Blake Park's rugby fields next month
by Tauranga City Council's spray contractor City Care.
It will be the first time in three years the chemical has been used in the city.
Several studies have documented that endosulfan can affect human development. Researchers studying children from a village in northern Kerala, India, have linked its exposure to delays in sexual maturity among boys.
Tauranga toxicology group Spraywatch has condemned the proposed city spraying.
Spokesperson Jacqui Martin said she was horrified that the council was using such a "terrible" chemical.
"Why would they kill worms anyway? I thought they helped keep the soil healthy."
Spraywatch naturopath Robin Grierson said it was a carcinogenic residual spray banned in many countries. She challenged the perception that the Western Bay had environmentally friendly councils who cared about the wellbeing of residents.
"No wonder our cancer rates are rising."
And while those approached by the Bay of Plenty Times agreed the insecticide was highly toxic, the council and turf experts insisted that the way it was applied meant it did not pose any risk to the public.
The spraying will take place after the end of the rugby season, although Hamilton-based sports turf scientist David Ormsby could not understand why the chemical was being applied in August when worm treatment should take place in late autumn and early winter.
Mr Ormsby, the central regions adviser for the New Zealand Sports Turf Institute, had few concerns about the chemical, providing spraying was carried out strictly according to the rules.
He explained that there were two or three Tauranga sports grounds that suffered very badly from worms. If they were not sprayed every two or three years, worm excretion across the top of the playing surface caused soft and muddy playing conditions.
"Not that we are against worms - they do a good job - but at certain times of the year they compromise playing quality."
Mr Ormsby said most councils in the central North Island used the chemical on their premier grounds. The few councils that did not spray for worms, including Auckland City Council, paid the consequences.
The spray needed to be immediately washed into the soil, which was why it was applied in light rain or irrigation systems were turned on. Potential risks declined very dramatically once it was washed in, he said.
Mr Ormsby said the majority of worms died underground, although if a bird fed on enough of the dead surface worms, it would die.
Tauranga City Council communications adviser Marcel Currin insisted Thiodan was being used sensibly and safely.
He said there was "very minimal" use of chemicals on Tauranga sports grounds compared with other cities and they were applied sparingly. He said it was not "wormicide" because the worm population always bounced back.
Mount Sports Club chairman John Blockley had not heard that a toxic chemical was about to be used on the fields, saying they went with the views of the experts on what was best for the grounds.
"You have raised something that I was unaware of and I will follow it up with the council."
Spraywatch is planning a meeting with the council next week to discuss the matter.
The manufacturer of the Thiodan described it as very dangerous but said it did not affect the human immune system. The International Agency for Research on Cancer concluded there was sufficient evidence that one of the ingredients, naphthalene, caused cancer in experimental animals but inadequate evidence for cancer in exposed humans, classifying it as a "possible human carcinogen".
