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Strawberry fields, California: for several days after methyl bromide application, the earth is covered with plastic, which, from outer space, looks like giant lakes. Photo: Barbara Dinham. |
Meanwhile, controversy over the European Union (EU) draft Regulation continues. The Council of Ministers agreed a position in December: to cut consumption of methyl bromide by 25% by 1998. But the European Parliament has just voted for a phase-out by 2000 (in their First Reading of the Regulation). The Commission says it is not willing to back the Parliament’s call for a phase-out. Member States are strongly polarised, with France, home of manufacturer Elf Atochem, defending minimal reductions, and Denmark at the other end of the spectrum. Denmark’s own draft national legislation to eliminate methyl bromide by 1998 has been blocked because the European Commission claims it is illegal under Maastricht rules and that it would be a barrier to free trade. Discussion on whether or not to phase out methyl bromide centres on several issues:
Ozone layer damage?
Some industry groups(4) claim new data suggest methyl
bromide’s Ozone Depletion Potential (ODP)—its ability to destroy ozone—is
likely to be smaller than the UNEP estimate of 0.7. They say that the scientific
uncertainties are so great that it is premature for governments to phase out
methyl bromide.
There are some uncertainties in the data, but all the
independent experts agree that methyl bromide depletes the ozone layer.
Scientists from NASA think that the ODP is unlikely to be less than 0.7, and
that the estimate of ozone damage may well increase, making methyl bromide as
damaging as CFCs.
Natural sources?
Emissions of methyl bromide from the oceans has led
some to claim that the pesticide is insignificant. However, ocean emissions have
for centuries been part of the natural balance of ozone breakdown and
replenishment. Human sources create a problem because they disrupt the natural
balance and destroy too much ozone. Human sources of methyl bromide—the
pesticide, leaded petrol, rainforest burning and chemical industry
emissions—are mostly preventable.
Alternatives?
There is certainly no single substitute, but
alternatives exist for some major uses, and a long list of potential
alternatives merits further research and development. Most soil uses of methyl
bromide have been prohibited in the Netherlands and Germany, mainly because of
water contamination. Farmers generally use crop rotation, steam or artificial
soil substrates instead.
Finding alternatives for warmer climates was thought to be
impossible. But a recent report from Italy, the largest European user, describes
some alternatives that have been tried and tested(5).
In 1983, water contamination led the Italian authorities to
ban the use of methyl bromide in a large, intensive horticultural area around
Lake Bracciano (near Rome). Growers mainly switched to steam for soil
sterilisation, but this was expensive. A combination of IPM and solarization has
been tested for several years on 14 farms, giving excellent results. Yield was
maintained (and in some cases increased), and the cost of the combined method
was very low compared to methyl bromide or steam.
In another part of Italy, a co-operative producing about 100
hectares of strawberries has reduced methyl bromide use by 70%. The co-op’s
technical advisers found that there were no losses in yield and that cost
savings were high.
After reviewing similar cases in diverse zones, the authors
concluded that methyl bromide use could be reduced by more than 60% in Italy
within a few years, and that it was also technically feasible to eliminate the
need for methyl bromide entirely.