“Hysteria” Of Antagonism To Insecticides

Press, Volume CII, Issue 30230, 7 September 1963, Page 10

“Hysteria” Of Antagonism To Insecticides

Workers who refused to handle D.D.T. were “caught up in the world-wide psychological hysteria of antagonism to insecticides which has followed the publication of Dr. Rachel Carson’s book ‘Silent Spring’,” said Mr J. M. Kelsey, officer in charge of the Entomology Division, Department of Scientific and Industrial Research, Lincoln, yesterday.

Mr Kelsey said also that "unrealistic” ceiling tolerances on D.D.T. residues in meat imported into North America were crippling NewZealand’s export meat industry. • Any danger from D.D.T. at Kempthorne Prosser and Company’s fertiliser works at Hornby was the result of workers refusing to wear the protective equipment provided, said Mr Kelsey. “They are advised by the Health Department to wear dust filters when handling dry mixes, and to wash their hands frequently, but often they don’t do this —parUy because they find the filters too hot in warm weather, and partly because they think it’s ’sissy’ to take precautions. This ‘chicken psychology’ can cause a lot of damage.” D.D.T. was “now-here near as hazardous" as some of the acids the same workers handled routinely" without complaint, Mr Kelsey added. Mr Kelsey thought the “whole business” of the recent hostile reaction to D.D.T. was “very unfortunate." He was particularly upset about its possible effect on NewZealand exports. Even the existing D.D.T. residue tolerances of seven parts per million (7 p.p.m.) in meat acceptable to North America was "crippling New Zealand’s meat export industry” by forcing the industry to conform to an unrealistic standard, he said. Although Mr Kelsev deprecated very strongly the "unrealistic” ceiling placed by the on D.D.T. residues in meat New Zealand could not. of course, jeopardise its export market by ignoring the requirement. The farmer who “wouldn’t play ball” and took risks with D.D.T. just because it was

thought to be safe was doing a grave disservice to his colleagues. Even if only one farmer in 1000 did this, he could ruin the market, said Mr Kelsey. Mr Kelsey could not. however, suggest w-ays of making sure farmers kept to the regulations: “We are up against human nature." he said.

Among available insecticides. D.D.T. was "the safest of the lot by a long way" if the amounts necessary for a similar degree of insect <:ontrol were compared. Experiment in U.S.

In an experiment with volunteer prisoners in United States gaols. Dr. Weyland Hayes, junior, had fed them D.D.T. with their food for 14 to 16 months, and the amount of the insecticide in their body fat reached 660 p.p.m.: yet there had been no absenteeism through sickness

and in fact no observable celeterious effect. The experiment was continuing. Another experimenter, Dr. Fennih, had fed himself D.D.T. in his food and water for 14 months without aiy evident ill effect. D.D.T. had been used widely in malaria control for over 50 years, and if any chronic ills were to be associated with its use they would surely have appeared by now, yet none had been reported.

"According to a World Health Organisation survey published in 1962. there ha* not been a single authenticated case of death through D.D.T. poisoning, uncomplicated by solvents or emulsifying agents." Mr Kelsey said.

’There have been cases where solution* or emulsion* of D.D.T. have caused trouble, but in these cases the material was being used in such a way that the solvent or emulsifying agent would have been dangerous on its own. “While D.D.T. is certainly a poison, there is every reason to think human beings can tolerate fairly large doses of it," Mr Kelsey concluded. Mr Kelsev thought D.D.T. in household insect-spray preparations w’as perfectly safe as long as “common-sense’’ precautions were taken, such as covering food and food plates during spraying.