No regulations for oestrogen in water supply, says Govt

Health officials say they will not be able to develop standards for drinking water that can screen for "gender-bender" chemicals until researchers in the United States have pinned down exactly what substances are involved.

"Reliable standards cannot be developed on the basis of hearsay information," said Michael Taylor, a senior adviser to the Health Ministry on environmental health.

Dr Taylor was commenting on research funded through Britain's Environment Agency which has shown that the urine of women who take the contraceptive pill is changing the sex of male fish in British rivers, and may be making some men less fertile.

The research showed that half of all the male fish in low-lying English rivers were changing sex as a result of water pollution, and that an "exquisitely potent" form of the female hormone oestrogen, found in the urine of women taking contraceptive pills, was contaminating rivers that supplied one-third of the country's drinking water.

Male fish were developing female characteristics in many of those rivers, and in some stretches, all the male fish had been "feminised".

But in New Zealand, Ministry for Environment officials said there were no regulations to control the discharge into waterways of oestrogen hormones in effluent containing the urine of women taking contraceptive pills.

This was largely because no one had yet shown adverse effects from such a discharge, and the lack of demonstrated effects meant there was not even a requirement to test for the compounds. Even if tests were made for endocrine disruptors, there was a lack of an internationally agreed testing procedure.

There would be no analysis able to reliably assess the effects of thousands of endocrine disruptors, probably until this was developed by the United States' Environmental Protection Agency, an Environment Ministry spokesman said.

At the Health Ministry, Dr Taylor said the possible presence of endocrine disrupters in drinking water had aroused international interest.

The United States research programme was complex because of the range of substances that may be involved, from household cleaners, insect repellents and the urine of women on "the pill", and the likelihood of the need for animal testing to establish the mechanisms.

Until there was hard information available on what substances had to be guarded against, the Health Ministry and the Environmental Risk Management Authority were "keeping a close watch on the topic".

So far there had been no obvious signs of endocrine disrupters having an effect in New Zealand, and he would have expected one to be evident from phthalates, used in cosmetics, insect repellents, and soft PVC plastics

EU governments stopped the use of phthalates in some baby toys, because of fears that the chemicals could harm babies by leaching out of toys in their mouths.

But Dr Taylor said some insect repellents that contained 25 per cent of phthalate have been in common use for many years and had been liberally smeared on people's skins during that time.

Dr Taylor suggest most water supplies in New Zealand were unlikely to be affected by endocrine disrupters because there were few water supplies in New Zealand that were heavily polluted by the household wastes that would contain them.

From May, water taken from the Waikato River below the effluent discharges of upstream communities will be piped to Auckland householders.

According to Matthew Bolland, a spokesman for the Auckland water retailer Watercare Services, an American expert, John Gaston -- the former vice-president of the American Water Works Association -- has said oestrogen will be effectively removed from Waikato river water by the coagulation and carbon filtration stages in the treatment plant for the pipeline to be opened in May.

Mr Bolland said Waikato water would be treated to the national "A grade" drinking standard -- equivalent to or better than Auckland's current standard of drinking water.

"The quality and safety for drinking purposes of Waikato treated water will be independently verified by the Auckland Medical Officer of Health before it enters Auckland's supply about mid-year," he said.

The "A grade" standard does not require removal of oestrogen and other endocrine disruptors which mimic it.

One of the leaders of the recent British research, Professor Charles Tyler of Exeter University, said that some of the oestrogen discharged into sewage was so powerful that even undetectable levels could have an effect.

"So we cannot be sure that some of these compounds, albeit of very low concentrations, aren't getting into our drinking water," he said.

- NZPA