This is Steve Ember with the VOA Special English AgricultureReport.

Some chemicals are very good atkilling insects and plants that cause trouble. But the trouble withthese chemicals is they can also harm people and the environment.This was the case with the pesticide D.D.T. It is now banned in somecountries. But others still use it. Another example involves thewidely used pesticide methyl bromide.

In nineteen-eighty-seven, nations met to discuss evidence of adecrease in the level of ozone in the atmosphere. Ozone helpsprotect against skin cancer from the sun. Negotiators met inMontreal. They developed the first part of an agreement called theMontreal Protocol on Substances that Deplete the Ozone Layer. Thistreaty sets out steps to protect the ozone in the atmosphere.

In nineteen-ninety-two, methyl bromide joined the list ofchemicals to ban. Developed countries agreed to end the use ofmethyl bromide by two-thousand-five. Developing nations have tenmore years.

The Bush administration says it will seek permission for someuses of methyl bromide at least until two-thousand-six. Theadministration says no replacement can be found for some farm uses.Other nations are also expected to seek special permission.

One-hundred-eighty-three nations have signed the treaty. TheUnited States Congress amended federal pollution laws innineteen-ninety-five. It did so to meet the requirements of theMontreal Protocol. Since then, the Department of Agriculture hassupported programs to find a pesticide to replace methyl bromide.

But its Agricultural Research Service says there is no onechemical or method that can do the job. One of the main problems isthat methyl bromide is used on more than one-hundred crops andproducts. It goes on as a gas in a process called fumigation. Thegas works quickly. It is able to kill worms, insects, harmful plants-- many different kinds of organisms. But this poison also affectsthe nervous system in people and is carried into the atmosphere.

The Montreal Protocol permits countries to continue to use somebanned chemicals if they must. Nations that signed the agreementhave organized a meeting this month in Montreal to discuss themethyl bromide issue.

This VOA Special English Agriculture Report was written by MarioRitter. This is Steve Ember.