The world community has declared war on the ozone-depleting agricultural fumigant methyl bromide. LOUISE THOMAS talks to a New Zealander in the forefront of the battle.
A New Zealander is now one of the leaders in the world battle against ozone-depleting substances.
Dr Tom Batchelor, from Whangarei, is a policy-maker for the European Commission in Brussels.
He spearheads international policy development and improved action on all ozone-depleting substances.
Dr Batchelor's contribution has been recognised by a Stratospheric Protection Award from the United States Environmental Protection Agency for his work towards phasing out methyl bromide - an agricultural fumigant used in most developed countries to treat soil before crops are planted.
The 46-year-old worked for HortResearch from 1980 to 1993, and helped to develop non-chemical quarantine treatments to replace methyl bromide. Those treatments are being adopted throughout the world.
"My work at HortResearch involved developing sustainable treatments for controlling pests that caused quarantine problems on New Zealand's horticultural exports," he says.
Methyl bromide, one of the chief ozone-depleting substances, is mainly used to control microbes, weeds and insect pests immediately before a new crop is planted each spring.
It is also used as a post-harvest treatment to kill pests, reducing the likelihood of export crops being rejected by quarantine authorities.
Methyl bromide is scheduled to be banned in developed countries in 2005 in accordance with the Montreal Protocol.
The compound was one of the most widely used pesticides in the developed world until 1992, when it was first listed as an ozone-depleting chemical under the protocol.
The Montreal Protocol is an international agreement that aims to phase out the production of such chemicals.
Methyl bromide has an ozone-depleting potential of 0.6 under a measuring scale used in the protocol.
Chlorofluorocarbons (CFCs), once used in everyday appliances such as refrigerators and air-conditioners, and now largely phased out in the developed world, have ozone-depleting potentials of about 1.0.
Chemicals with potentials as low as 0.01 are being phased out based on protocol agreements.
Scientists involved in ozone-layer protection have identified methyl bromide as one of the main depleters of stratospheric ozone and the elimination of all man-made sources is a top priority.
Dr Batchelor's work in New Zealand was aimed at determining the responses of pests and horticultural exports to a range of disinfestation treatments.
They included heat, controlled atmospheres, physical removal and irradiation in various combinations or applied separately.
"The programme was developed in partnership with industry, which would then go out and use the technology we developed," he says.
"In the early 1990s, industry was particularly supportive as the programme improved market access and addressed producer and consumer concerns about chemicals on human health and the environment."
In New Zealand, methyl bromide has been used for soil treatments for strawberries, apples, mushrooms and other crops, but over time many of these uses have been substituted with alternatives.
In the past methyl bromide was crucial in maintaining New Zealand's freedom from accidentally imported pests.
More recently, the Ministry of Agriculture and Forests has implemented a strategy under which the exporter is responsible for sending consignments free of pests.
Contaminated consignments are rejected, then returned or destroyed. Shipments can only resume when procedures that minimise pest contamination have been put in place.
About 70 per cent of the methyl bromide use is in developed nations, with about 35 per cent in the United States on strawberry and tomato production.
The European Union has now reduced its use to 40 per cent of 1991 levels.
"Fortunately, many developing countries have never relied on methyl bromide for crop production as many chemicals are too expensive, and instead have depended on chemical-free methods of pest and disease control," says Dr Batchelor.
"Such methods are now sought-after by growers in developed countries."
While still in New Zealand, Dr Batchelor was invited to become a founder member of the United Nations Environment Programmes Methyl Bromide Technical Options Committee.
He was co-chairman of a group responsible for providing reports to about 170 governments operating under the Montreal Protocol on technical, economic, environmental and trade issues.
Those reports have formed the basis for governments making decisions on international environmental agreements and national legislation.
"In the committee, there was always debate - often heated - between chemical manufacturers, environmental representatives and scientists," he says.
"But in the end a consensus document that reflected each viewpoint was agreed."
After a stint in Australia, Dr Batchelor moved to Brussels in 1999 to take up the post of principal administrator (ozone-layer protection) for the European Community.