Pesticides and food -new study

Press, 9 July 1980, Page 14

Pesticides and food -new study

Bv

OLIVER RIDDELL

A new investigation of tire trace elements and pesticide residue in food is being considered by the D.S.I.R. and the Department of Health. They have already done one such study, published in 1978, which received very little public attention. The new study is still being discussed. It is unlikely to provide any further information for the public for several years.

Until it is published, the earlier study will be the definitive work. Although not showing any dangerous levels in food, some trace elements and pesticide residues gave some cause for concern. Christchurch leads the country in a higher iron content from cereals than is normal.

The presence of mercury in New Zealand trout as a result of the natural discharge of mercury from geothermal areas was first shown in 1973. Several other studies since have looked at the levels of mercury and other heavy metals in fish and shellfish. Considerable attention has been apid to determining pesticide residues in horticultural produce and meat. Studies during the 1970 s showed the chemical levels in human bodies as a result of food intake.

A weekly menu for the earlier study was compiled for each of the four quarters of the year to allows for seasonal variations in availability and consumption. Foods were bought on a random basis at retail shops in Auckland, Wellington, Christchurch, and Dunedin in April, August, October

and January of 1974-75 and airfreighted to Wellington. Items were prepared for eating but not cooked. The edible portion of each was weighed. The diet was then divided into eight groups. These Were chosen to simplify analysis and to identify food types that contribute most to any contaminant concentration found.. This is known as the “market basket” method. The eight groups were:

grain and cereal produce; meat; fish and eggs; dairy products; vegetables; fruit; beverages and confections; imported and canned food. This “market basket" totalled 3306 grams of food a day. The simulated diet was planned to provide 4000 kilocalories a day for an active young man, consuming a larger and more varied diet than most people. Of the trace elements, antimony was not detected. Cobalt consumption was considered normal. The average intakes of chromium, copper, iron, and zinc were all at, or above, the upper limit of the range of daily requirements. Christchurch’s much higher iron content from cereals thin, is normal from largfely refined cereals, suggested that a flour or cereal product in this part of the test may have contained some form of metallic contamination.