COCA, POPPY KILLER MAY HARM AMAZON

BOGOTA, Colombia (AP) - Deep in the jungle, a Turbo-Thrush plane swoops to
within 100 feet of a field of illegal drug crops, lets loose a cloud of
herbicide over the plants and soars skyward again before heavily armed
leftist rebels can open fire.

It has become an almost daily - if hair-raisingly dangerous - routine in
Colombia as police undertake an ambitious program to eradicate thousands
of acres of coca and poppy - the plants used to make cocaine and heroin.

Now, at the urging of the United States, Colombia is considering switching
to a more powerful, granular herbicide called tebuthiuron - a new
coca-killer that can be dropped from higher altitudes, out of range of the
gun-toting rebels guarding the crops.

Environmental groups and some top Colombian officials oppose the switch,
contending that tebuthiuron, produced by several companies, is dangerous
to human beings, animals and the delicate Amazon rain forest - one of the
world's treasure chests of biologic al diversity.

``We can't authorize at this time a substance that could harm our
ecosystem,'' argued Environment Minister Eduardo Verano. ``We cannot
attack the Amazon.''

He has refused to sign off on a proposed field test, asserting that
tebuthiuron could turn the lush jungle into a prairie.

A Colombian government commission will decide in coming weeks whether to
approve testing on a wide swath of jungle.

Environmentalists in the United States note that tebuthiuron is most often
used to clear weeds near highways and is rarely applied near desirable
vegetation.

``It is a very large contradiction to say it is safe to use'' in a rain
forest, said Mauricio Castro, head of the Colombian office of the World
Wildlife Fund. The chemical could seep into ground and surface water in
dangerous concentrations, lingering for a year or more, he says.

Charles Helling, lead scientist of the U.S. Department of Agriculture's
narcotics group and member of a U.S. team that briefed Colombian officials
on tebuthiuron last month, disagrees.

``The benefits are so strong,'' he said by telephone from his Beltsville,
Md., office, adding: ``In my judgment, the environmental risk is very
slight.''

The urgency of crop-eradication efforts are evident. Colombia overtook
Peru last year as the top coca producer, with 307 square miles of crops
under cultivation, the State Department says. Despite a record eradication
effort, police haven't destroyed crop s as fast as new ones are planted.

Colombian traffickers control 80 percent of the global cocaine market and
a growing share of the heroin trade. Leftist rebels have increasingly
turned to working with drug traffickers and guarding coca crops to finance
their decades-old insurgency.

So is tebuthiuron, backed by Colombia's police chief, the answer? In the
late 1980s, Peru tested the herbicide, but opted against using it for fear
of provoking social unrest in coca-growing regions.

Ivonne Alcala, head of the Colombian anti-drug office, expects such
protests here: In 1996, farmers staged a violent protest against
glyphosate, the herbicide currently in use, leaving seven people dead and
about 100 injured.

``If we were spraying holy water, they would say the holy water is causing
birth defects,'' Alcala said.

If it is used, tebuthiuron would be dropped in tiny pellets, not a mist,
allowing pilots to fly higher and faster. That would let them avoid rebel
fire that has brought down 12 anti-drug aircraft since 1994. The pellets
also make the herbicide more resist ant to rain, which frequently washes
away glyphosate.

Helling said tests he conducted indicate the chemical would disappear
faster in the humid forest than in the United States, making it less
harmful. But even those who say it is relatively safe acknowledge it could
be dangerous to children or people with l ow resistance.

``Individuals have different levels of sensitivity,'' said William Smith,
a Cornell University agriculture professor. ``I myself would not like to
be in a spray drift area where this material was being applied.''