tap water 'dangers'

Cancer-causing trace metals in plumbing fittings -- including lead, cadmium, copper and nickel -- have the potential to leach into drinking water and cause long-term health problems, the Ministry of Health has warned.

Every local council nationwide is now required under the Drinking Water Standards for New Zealand 2005 to alert consumers to the potential danger and advise them how to avoid it.

In a public health notice issued by Porirua City Council today, New Zealand's Director-General of Health Karen Poutasi said some plumbing fittings had "the potential to allow minute traces of metals to accumulate in water standing in the fittings for several hours".

"Although the health risk is small, the Ministry of Health recommends that you flush a mugful of water from your drinking-water tap each morning before use to remove any metals that may have dissolved from the plumbing fittings," Dr Poutasi said.

"We are recommending this simple precaution for all households, including those on public and private water supplies."

Earlier this year, Wellington Regional Council, as the reticulated water supplier for the region, took out a public notice in daily newspapers to advise consumers of the issue, and local bodies have also included notices in rates newsletters.

Drinking water assessor Scott Rostron, from the Wellington Regional Public Health Service, said the potential long-term harmful effects from trace metals in plumbing fittings had been known for a number of years.

The new warnings had not arisen from any changes made by councils to the way water was supplied, he said.

Actual exposure would depend on the age and type of the plumbing fittings in individual houses.