The Selwyn St, Northeast Valley, property has been occupied since March by three adults and three young girls, including a 1-year-old.
Council staff said the tenants were supposed to have been warned about lead contamination at the property and should have been told not to eat vegetables or fruit grown there.
Otago Regional Council (ORC) tests found lead levels between two and nearly four times the safe limit for residential use.
Tenant Brett Cook (24) said the first he and his family knew of the contamination was when he read about it in the Otago Daily Times.
His home was on the list of 140 confirmed contaminated sites in Otago, released by the ORC and published on Saturday.
Mr Cook and his partner - who would not be named - planned to seek medical advice, fearing the contamination could explain the recurring sickness of their children, including the "constant" illness of their 1-year-old.
"The only thing we were told when we moved into this place was it was going to be pulled down within five years. The contamination of it - we had no idea.
"It's come as a bit of a shock," Mr Cook said.
Council support services manager Gerard Collings confirmed the house had been rented out since it was purchased by the council about four years ago.
It was one of 11 residential properties owned by the council.
The ORC contracted Harveys Dunedin to manage the properties.
It was the only property known to be contaminated, and Harveys had been instructed to warn tenants, he said.
"My understanding is that has occurred," Mr Collings said when first approached.
Told the tenants said they had not received the warning, Mr Collings said: "It concerns me I have been misled and it would concern me if there [were] health issues as a result of their tenants not being advised appropriately."
Soil samples taken in the years since the site was bought had found lead levels of between 700mg and 800mg per kg of soil, and one of 1100mg/kg, council resource management director Dr Selva Selvarajah said.
The acceptable maximum soil lead level for residential properties was 300mg/kg.
The council bought the property for the Leith-Lindsay flood protection scheme.
The contamination was believed to be from the Beggs Wool Scourers, Sheepskin, Mat and Rug Factory's operations in the area between 1886 and 1904.
Mr Cook said he had been contacted this week by Harveys staff wanting tenants to sign a document confirming they now knew about the contamination.
The tenants had been improving the five-bedroom home, inside and out, including replanting gardens, he said.
The couple had pet dogs, their children regularly played outside and they had planned to start a vegetable garden this summer.
"I'm very annoyed now," Mr Cook said.
Harveys principal Bruce Robinson said when contacted there was "absolutely no question", his staff had "slipped up" in forgetting to include the warning of contamination in the tenancy agreement.
Asked if the error had placed the tenants at risk, Mr Robinson said: ". . . I'm not answering that."
His staff "may have" incorrectly advised the council tenants had been warned of contamination, but "I can't categorically say . . ."
"It may have been mentioned in passing," he suggested.
Mr Collings met the tenants yesterday, and they would be allowed out of their lease, without penalty, should they decide to leave, he said.
He also had "had a serious talk" with Harveys, which was reviewing its processes to ensure there was no repeat.
Public Health South health protection officer Andrew Shand, whose office is responsible for investigating lead poisoning cases, said there had been no recent communication about the property.
Lead poisoning
- Lead levels in soil at Selwyn St site between two and nearly four times higher than maximum limit for residential use.
- House owned by Otago Regional Council, listed as contaminated site, but rented out through Harveys Dunedin.
- Council instructs Harveys to warn tenants not to eat produce grown on the site; warnings not given to current tenants, who fear lead could be responsible for their young children's recurring sickness.
What the Ministry of Health says. -
- Lead can be absorbed through food, water, dust or fumes; some people may develop serious health problems if lead accumulates to toxic levels.
- Sources of lead include old plumbing and paint on houses (which can contaminate surrounding dust and soil), occupational or industrial sources of exposure.
- Children under 5 are "particularly at risk"as they often place contaminated objects and fingers in their mouths. Reducing a child's exposure to contaminated soil is recommended.
- Adult symptoms of lead poisoning range through cognitive and memory problems to depression, head and body aches, nausea, diarrhoea, and problems with blood, kidneys, bones, heart and even extending to reproductive health.
- Pregnant women and their unborn children are particularly vulnerable.
- Even small amounts of lead can cause serious health problems. Children under the age of 6 are especially vulnerable to lead poisoning, which can severely affect their mental and physical development.
