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Salient. Victoria University Student Newspaper. Vol 35 no. 4. 22 March 1972

Danger to Humans:

Danger to Humans:

How serious in fact is the risk to people from the dioxin in 2,4,5-T? The bulk of NZ 2,4,5-T is made in New Plymouth by Ivon Watkins - Dow, who state that their product contains only about 0.5 -0.8 part per million dioxin. This may seem an impressively low impurity, but in fact even this level is significant. The most obvious way a woman could take a dangerous dose of dioxin from 2,4,5-T is through drift of aerial spray. Farmers end advisory officers are familiar with the fact that sprays laid from the air can and do drift for miles even on fairly calm days. If such a spray drifted on to a farm roof from which drinking water is collected, even the 0.5 ppm of dioxin in the 2,4,5-T could administer a daily dose of about 0.015 microg./kg. to a woman in the house. This figure was calculated by the Chairman of the Agricultural Chemicals Board, Mr P.J. Clark; he points out that such a dose is very unlikely, but that it is possible. If we now compare this possible dose from aerial spraying with the maximum safe dose indicated by experiments on animals, given above, we notice that the dose to the woman would be thousands of times the safe level. In fact, even if we were to ignore the safety factor (which no responsible scientist would do), we notice that the possible dose to a woman calculated by Mr Clark (0.015 microg./kg. daily) is very close to a dose (0.02 microg./kg. daily) which is positively known to cause foetal damage in the hamster.