Picton residents have nothing to fear from drinking water which runs through asbestos cement water pipes, says a health official.
Construction crews repairing a burst pipe under Devon St on May 5 wore masks, raising concern over potential risks of drinking water contaminated with asbestos.
Nelson Marlborough District Health Board medical officer of health Ed Kiddle said inhaling asbestos fibres can cause lung cancer, but there was no danger in ingesting it in small quantities such as those that might be found in drinking water.
"We may get some minuscule amounts in the water but there's no evidence of problems arising from ingesting it," Dr Kiddle said.
Asbestos-based products were commonly used in construction until the 1980s, Marlborough District Council operations and maintenance engineer Steven Rooney said.
About 30 per cent of Blenheim's water pipes are made from the material.
Crafar Crouch Construction water reticulation officer Wayne Bowden said contractors wore masks when repairing the pipes to avoid breathing in any of the dangerous fibres.
"Drinking asbestos is not a risk in a burst situation because it is never dry ... It is only because of the saw [used to cut out the broken pipe], which dries it to dust, that it becomes airborne."
Marlborough District Council engineering officer Kerry Walsh said at least one pipe has burst in Picton every month over the last four months.
They replaced broken asbestos cement pipes with plastic material such as PVC.
The council planned to replace all pipes from Oxford St across to York St and down to Broadway St in June as part of ongoing maintenance as and when required, Mr Walsh said.
The Health Ministry's draft guidelines for drinking-water quality management, last updated in 2005, stated that studies showed little evidence of danger to populations who had high amounts of asbestos in their drinking water.
Extensive studies on animals showed consuming asbestos did not consistently increase the number of cancerous stomach tumours.
"The weight of the evidence shows ingested asbestos is not hazardous to health," the report said.
- © Fairfax NZ News