Toxicology Research Unit May Be Established Again

Press, Volume CV, Issue 31028, 6 April 1966, Page 9

Toxicology Research Unit May Be Established Again

The New Zealand Medical Research Council may re-estab-lish its Toxicology Research Unit. Dr. J. M. Barnes, director of the Toxicology Research Unit of the United Kingdom Medical Research Council, was in New Zealand recently to advise on the project.

One of the main studies of the proposed unit would be toxic substances in foodstuffs, said a spokesman of the New Zealand Medical Research Council. With the steep rise in the use of pesticides in New Zealand agriculture and the use of food additives, problems had been created in the safe handling of foodstuffs.

To maintain the quality and quantity of its primary production New Zealand must continue to use pesticides. Unfortunately the risk of traces remaining in foodstuffs existed, and this in itself was a good reason for the reestablishment of the Toxicology Research Unit, said the spokesman. Export Produce Another good reason was the fact that New Zealand’s economy depended largely on the marketing of produce overseas, where sales could be affected adversely if high standards of purity were not maintained. Some years ago the United States rejected New Zealand exports because they contained traces of dieldrin. Use of dieldrin was virtually banned in New Zealand, less persistent substitutes were found, and intensive work was begun into pesticide residue taint of meat and dairy products.

DD.T. was now used on pastures under carefully-

controlled conditions, withholding periods being prescribed for stock after its application because animals grazed on freshly-treated pastures were likely to ingest D-D.T. and store it in their tissues or milk. Studies in America over the last 12 years had shown conclusively that D.D.T. found in human body fat had as its source the D.D.T. present in the animal fat constituents of the American diet. The level had not changed significantly over the 12 years studied, and it seemed to be one which the body could tolerate. “Seems Questionable” This now seems questionable. Recent work with D.D.T. had shown that quite small doses fed to experimental animals had a profound effect on the metabolysing enzymes in their livers. The discovery pointed to the need for further research into the effect of D.D.T. on mammals and a reassessment of its safety. “The level of D.D.T. present in New Zealand food products has not so far proved dangerous to the New Zealand consumer, but a big responsibility rests on research organisations tn seek more satisfactory pesticides or improved ways of using those we have,” said the spokesman. The re-establishment of the Toxicology Research Unit would also enable checks to be made on imported products. The need for such protection had been shown in the last two years by the discovery that cargoes of ground-nuts and ground-nut meal might be contaminated by aflatoxin, a powerful natural poison produced by a common fungi. Like other countries aware of this hazard New Zealand checked for aflatoxin and refused to accept contaminated cargoes. Toxic hazards were covered

by the Poisons Act, 1960. Tins required every toxic substance newly imported, manufactured, or prepared in New Zealand to be registered with the Department of Health and details given of its constituents and proposed use. The Department of Health, after thorough examination, then decided whether the substance was safe for distribution.

The information was also sent to the Poisons Information Centre in Dunedin, which kept a central record of all toxic substances on the New Zealand market and the remedial treatment needed for each in case of poisoning. The centre provided a 24hour emergency information service far the whole country.

“While the Poisons Act authorises action to prevent dangerous substances from being used in agriculture and industry, its administration could be more effective if advice were available from a team of experts working on toxicological problems in New Zealand,” said the spokesman. “It is not easy to gather the supplementary information necessary to decide whether a substance is safe. So many new materials are produced that often they have no background to work on.

“Furthermore, it is unwise to generalise about toxic substances. Used in one way a substance may be harmless, and in another it becomes dangerous.

“Circumstances play such a part in determining the toxicity of a substance that New Zealand would be well served by a toxicology research unit of its own such as is envisaged by the MediCal Research Council.”

London Visit—Mr Dudley Senanayake, Ceylon’s Prime Minister, arrived in London yesterday from Paris for a week’s official visit.—London, April 4.