ROUNDUP WORKS -- BUT TOO WELL?

It's a common weed killer and the world's best-selling pesticide. Sometimes
referred to by its chemical name, glyphosate, it's better known
commercially as Roundup.

Odorless and apparently only slightly toxic, you can buy it for your back
yard at any large supermarket.

So why is its use kicking up such a stink in Colombia?

Colombian police have been using it for more than a decade as the weapon of
choice in the aerial spraying of coca plants and opium poppies used in the
production of cocaine and heroin.

Not surprisingly, coca farmers have been opposed to Roundup from the
beginning. Authorities have never taken their complaints seriously.

But lately the protests have gained strength -- and legitimacy.

That's because drug crop spraying has dramatically intensified in the past
eight months as part of a new joint U.S.-Colombian counter-drug strategy,
Plan Colombia. Last year the U.S. approved $1.3-billion for the plan. More
than $676-million is on the table this year.

Much of that is being devoted to an all-out air and ground assault on the
crops.

The United States and Colombia argue that the spray campaign is a key
element to wiping out the drug trade. In so doing, they believe this also
will help achieve peace in Colombia, a country torn by 40 years of brutal
conflict, which has seen rival armies of left-wing guerrillas and
right-wing paramilitaries fight for control of drug-producing areas.

But critics say Roundup is hurting much more than the illicit crops it is
designed to destroy. Its application in Colombia has come under fierce
attack from peasant groups and agricultural experts who blame it for a
sudden spate of reported illnesses and environmental contamination.

A Colombian agronomist, Elsa Nivia, says that in the first two months of
this year, local authorities reported 4,289 humans suffering skin or
gastric disorders, while 178,377 creatures, including cattle, horses, pigs,
dogs, ducks, hens and fish, were killed by the spraying.

In February, Colombia's national ombudsman demanded a halt to spraying
after his office was flooded with complaints of glyphosate poisoning.
Equally perturbed, the representative of the United Nations Drug Control
Program in Colombia last month called for the setting up of an
international auditing mechanism to investigate the allegations, as well as
long-term monitoring of the spraying.

But U.S. and Colombian officials strongly deny the spraying is responsible.
Instead, they accuse local peasants and activists of spreading a sinister
campaign of disinformation.

"Glyphosate has been the subject of an exhaustive body of scientific
literature which has shown that it is not a health risk to humans," Rand
Beers, the State Department's top counternarcotics official, said at a
Senate hearing last month. "It is used throughout the United States and
over 100 other countries and has been rigorously tested for safety for
animals and humans."

All is true. Mr. Beers also might have pointed out that glyphosate is used
by the forestry service in California to control undergrowth when saplings
are planted. It's also used in the Everglades to attack the pesky spread of
alien species like melaleuca.

But Colombian critics, who are increasingly gaining a voice in the United
States among foreign policy watchdogs and concerned members of Congress,
say the State Department isn't telling the whole story.

They allege the solution being used in Colombia is of a higher
concentration than is commonly applied in the United States. Chemical
additives also are being mixed into the Roundup in Colombia to improve its
efficacy. Some experts warn these additives, including the surfactant
Cosmo-flux, have never been properly tested in the United States, and might
be the cause of skin irritation and other illnesses in Colombia.

They point out that Roundup is used in the United States only in highly
controlled circumstances, in areas far from human habitation. In Colombia,
that is clearly not the case. While great care has been taken to protect
the larger towns and villages near the spraying, more remote communities,
including native Indian homes and farmsteads, have been sprayed.

They also warn that Roundup testing in the United States likely never took
into consideration such intense use in the fragile ecosystem of southern
Colombia, a low-lying region of tropical rain forest, where large rivers
flow into the Amazon.

They also question whether its use in Colombia is in accordance with strict
U.S. regulations, which require Roundup's manufacturers to provide detailed
descriptions on their products' labels. These labels contain the warning:
"It is a violation of federal law to use this product in any manner
inconsistent with its labeling."

The labels warn that contact with eyes or clothing might cause eye
irritation in humans, as well as gastrointestinal irritation in domestic
animals. Roundup should not be applied "directly to water," or "to areas
where surface water is present."

In the case of one brand, Roundup Ultra, which critics say is one of the
products being used in Colombia, the directions warn against adding any
surfactant to the spray mix.

The State Department, belatedly perhaps, announced last month that the U.S.
embassy in Bogota is sponsoring a study into the issue. It added that a
U.S. contracted physician -- described as 'Colombia's leading toxicologist"
- -- had completed evaluation and treatment of several hundred people in the
southern department of Putumayo.

The results of his report are anxiously awaited. Can it be that so many
peasants are lying?

Times staff writer Paul de la Garza contributed to this report.