New Zealand spotlights herbicide leakage

New Zealand is the last country in the world making 2,4,5-T, the controversial herbicide used in Agent Orange, the defoliant sprayed by Americans in Vietnam.

Ivon Watkins-Dow, the subsidiary of the Dow Chemical Company of America that manufactures the chemical, is under fire here for two leakages last year into the Tasman Sea. Chemicals leaked from a waste dump it maintains near its plant at New Plymouth, on the west coast of the North Island.

The first incident occurred last February. The second, in November, involved 2,4,5-T and 2,4-D - the two constituents of Agent Orange. This leakage was not revealed by the company for two weeks, prompting tough words from Health Minister Anthony Malcolm.

''This particular incident may be minor, but given the public concern about these pesticides in particular, Ivon Watkins-Dow's apparent desire for secrecy does not improve my confidence in them,'' he said.

Both leaks were detected in rock pools on a beach where local Maoris gather shellfish. The Health Department confirmed both times that the concentrations in the leaks were not high enough to harm marine life or pose a public health hazard.

But public concern remains, and Mr. Malcolm is demanding an explanation why the company sat on news of the leak for two weeks before telling his department. The company has said only that it took that time for its research scientists to confirm there had been a leak.

Ivon Watkins-Dow is 50 percent owned by the Dow Chemical Company, which announced in October that it was abandoning a $10 million fight to continue marketing 2,4,5-T in the US because its waste-disposal system did not meet approved standards. Weeks earlier, manufacture stopped in West Germany. Japan, Italy, the Netherlands, and Sweden have banned use of the chemical.

The New Zealand company produces about 700 tons of the defoliant a year, mainly for this country's farmers, who still use it widely to control weeds, especially furze. About 100 tons is exported to Australia, Malaysia, and other countries in the Pacific basin.

Ivon Watkins-Dow is adamant that there is no conclusive proof that 2,4,5-T causes environmental or health problems. Environmental groups say the herbicide, which contains dioxin (reputed to be the most toxic synthetic chemical on earth) , causes cancer, birth deformities, and other serious health problems.

British agricultural workers have expressed fears that Ivon Watkins-Dow will start exporting to Britain, where the chemical has not been manufactured since 1976, but where its use is not banned. But Ivon Watkins-Dow says it has no plans to boost production for export.