‘CRITICAL ’ MERCURY LEVELS

Press, Volume CXII, Issue 32819, 20 January 1972, Page 1

‘CRITICAL ’ MERCURY LEVELS

(Dew Zealand Press Association)

TAURANGA, January 19.

Reports of mercury contamination found in fish from the Waikato River and the Bay of Plenty are an indication that New Zealand is close to the international safety limits on mercury levels, according to the president of the council of North Island Acclimatisation Societies (Mr J. B. Prior), speaking in Tauranga today.

He says that contamination in fish in and around Tauranga Harbour already may contravene American and Japanese' standards.

The mercury levels were disclosed yesterday by the managing director of Mount Maunganui‘ Marineland, Ltd (Mr P. R. Sprrenson) from analysis of fish.

Mr Prior, who is also a member of the Pollution Control Council, said that the council was studying mercury contamination in New Zealand “very closely.”

The pulp and paper industry was responsible for a large part of the mercury pollution round the world, he said. But fungicidal sprays—many of which contained mercury—were also an important contributor. Mr Prior said that the Health Department would have the results of the analysis and should take further tests, inside and outside the harbour.

“This is a public health matter. It must be followed up.” The district medical officer of health at Rotorua, Dr C. J. Christmas, said today that the level of mercury in the Tauranga fish seemed “incredibly high.” Mr Sorrenson said yesterday that trevalli and herrings taken locally to be used for feeding at the aquarium had shown mercury levels higher than the safety limits for the United States, Japan and Sweden.

Although he did not disclose the source of his analysis, he said that the trevalli showed 1.5 parts per million of mercury and the herrings 1.2 p.p.m. The United States limit is 0.5 p.p.m., and in Japan and Sweden 1.0 p.p.m. Dr Christmas said that he had no prior knowledge of the Marineland analysis. But if such a high mercury level was substantiated it would be of tremendous importance. However, he was at a loss to know where the mercury was coming from if the

Marineland analysis were true. ‘A fish a week’ Another scientist has urged the Health Department to designate acceptable levels of mercury in New Zealand food.

Dr G. R. Fish, the Marine Department biologist at Rotorua, says that research is urgently needed to show the extent of the mercury in the water. He sees the main sources as being geothermal power generation and from wood pulping. The present investigation

pointed to the constant need to check the quality of water when it was being used by industry. “It gives me an uncomfortable feeling that there is a good deal of mercury about, and I would like some clue on how much fish it is safe to eat. “If levels are high, perhaps people should eat only one fish a week.” U.S. experience A further note of warning has been sounded by Professor V. J. Chapman, head of the botany department at the University of Auckland. He said today that New Zealand needed to do more, particularly in the light of what was known to be happening in the Great Lakes in North America. The medical officer for health for Auckland (Dr N. T. Barnett) said that his department was watching the situation and was aware of the problem. The standard set as the safe upper limit for mercury in fish was 0.5 parts per million. Arsenic found Water and weeds in some parts of the Waikato River contain high—but not dangerous — percentages of arsenic, according to two leading Auckland botanists. Professor V. J. Chapman and Dr N. M. A. Brown, both of. the University of Auckland, recently made tests on weeds in inland lakes and rivers in the Waikato catchment area.

The highest concentration of arsenic in water was found in the outlet from Lake Ohakuri, near the discharge of the Wairaki thermal station. Here the level was 200 parts of arsenic per 10,000 m parts of water. This borders on the “danger level,” according to acceptability standards set by the World Health Organisation, but poses no . real threat because arsenic is quickly broken down by water moving downstream, says Dr Brown.