Lead scare: Unsafe levels found in children's blood tests

Asked at a Waikouaiti Coast Community Board meeting last night if the communities north of Dunedin were looking at days, weeks or months of using alternative supplies, Dunedin City Council 3 Waters group manager Tom Dyer said the timeframe of days could probably be excluded.

"Weeks is a possibility. Months is more likely."

The communities have been advised since February 2 not to drink tap water, nor use it for cooking, after an elevated level of lead was detected at the Waikouaiti raw water reservoir last month.

Waikouaiti Coast Community Board members and Dunedin City Council and health officials discuss lead in drinking water supplies, as members of the public watch. PHOTOS: GREGOR RICHARDSON

Residents have been having blood tests, as authorities look to establish whether there could have been chronic exposure to lead.

Southern District Health Board medical officer of health Dr Susan Jack has confirmed some blood results have come in above the level of 0.24 umol/L, which is the amount that triggers follow-up inquiries.

Unsafe lead levels found in children's blood tests

As expected some people have come back with levels that are higher than the cut off of 0.24 micromoles per litre. It's not very common when we look at the whole population that was tested," Dr Jack told RNZ.

However, she would not be drawn on how many people had recorded high levels.

Further investigation was needed, particularly in the cases of children, she said.

"The first test usually on the children it was a finger prick or heel prick - it's a screening test. Then we need to confirm that using a venous sample."

All those showing concerning blood lead levels were contacted.

Waikouaiti Coast Community Board member Mandy Mayhem-Bullock asks questions of officials at a meeting last night.

"We're going through understanding what possible risk factors and exposures they might've had and then, especially for the children, we're offering a visit out to their home to look at where there are other environmental risks. So is there lead paint, is there renovation, are they involved in hobbies, do their parents work in a place that might have exposure to lead," Dr Jack said.

"There are many causes of elevated lead and we need to determine is water part of that or can it all be attributable to other causes?"

A father of three who spoke at the meeting said he had concerns for his youngest child after the two-year-old experienced health problems last year as she suffered a loss of appetite and weight, as well as greying of the skin.

After testing the girl for everything from cancer to coeliac disease, the revelation of lead in the drinking water came as a shock, the man, who did not want to be identified, said.

"We're not sure that it [lead poisoning] is the cause but it's just another question to ask a doctor and pediatrician," he told RNZ.

The family had been tested and all came back below the safe level, he said.

"After today I do feel a bit better. I've still got health concerns and questions that haven't been answered on that, but hopefully they'll be answered soon."

Questionnaires are used to determine whether the historical use of lead in paint and petrol and other possible sources could explain elevated lead levels in people tested.

Analysis of broad patterns from the tests has not yet been completed.

Dr Jack said at the meeting that comparisons would be made against a New Zealand survey in 2014 to 2016, as well as international data.

Cr Jim O’Malley raised the possibility of false positives from water tests at Waikouaiti and Karitane.

Six water samples since July had shown elevated lead levels and it appeared some could be explained by a section of old cast-iron pipe in Waikouaiti that was being replaced.

Cr O’Malley has called other readings "enigmatic".

He described a puzzle, where high readings at two sites from December 8 samples were not reflected elsewhere in the network, including the raw water reservoir.

"There’s no easy explanation for those numbers," he said.

"We can’t eliminate false positives at this point."

Mr Dyer said the council was treating the positive tests as real while it worked to eliminate possible sources of the contamination.

The council is unable to re-test the December samples, as they have been discarded.

- additional reporting RNZ