First Carlitos, with the expressive face and limbless body.

Next came Jesus, with an underdeveloped lower jaw and a swallowing problem.

Then there was the infant with a missing ear, no nose and no visible sexual organs. This baby was named Jorge - Spanish for George. Three days later the infant died, and an autopsy revealed her gender.

The death certificate renamed the child Violeta.

Three deformed babies born during a seven-week period to farmworkers in Immokalee.

All six parents worked in the same tomato field on a farm owned by Ag-Mart Inc., a Plant City-based firm that is one of the largest produce operations in the state.

The families lived within 100 yards of one another in the farm's migrant camp when the women became pregnant early last year.

What else might they have had in common?

Since March, health and agriculture investigators have searched for a cause of the defects.

They are not likely to find one.

``We don't know what causes 80 percent of birth defects,'' said Jane Correia, who administers the state's birth defects registry.

That's a problem not only for farmworkers but also for the nation, some health experts say.

According to the National Research Council, half of all pregnancies end in a birth defect, the loss of the baby or a chronic health problem, such as childhood cancer, severe asthma or autoimmune disorders.

``Many of these things we are beginning to suspect have a prenatal origin,'' said Betty Mekdeci, executive director of Birth Defect Research for Children.

``Even if there is a genetic predisposition, that doesn't mean it wasn't triggered by something in that prenatal environment.''

Mekdeci's organization was founded in 1982 and since 1990 has sponsored a national birth defects registry.

The registry, the only of its kind, has been involved in identifying clusters of birth defects in different parts of the country: babies born without brains in St. Charles, La.; an unusual cranial-facial abnormality found in the offspring of some Gulf War vets; a high incidence of cleft palate in Dixon, Tenn.

The latter case, not far from Nashville, was linked to water contamination from an old landfill.

``A cleft palate can be caused by a lot of things, but if you find a cluster of cleft palates and an exposure to something known to cause it, you have a case,'' Mekdeci said.

That link, she said, would be difficult to establish in the Immokalee babies.

``You look for similarities, and unfortunately these cases are not similar in any way.''

Many Possibilities

In Immokalee, there is no common birth defect and no isolated exposure to link them. Too many factors may have contributed. And too much time has passed since some unknown agent delivered the developing embryos a devastating blow.

``At the end of this, I predict that everyone will still be shrugging their shoulders and wondering what went on,'' said Gina Solomon, a senior scientist with the Natural Resources Defense Council.

Collier County health officials have collected detailed accounts of each family's medical history, family history, nutritional habits, work habits and possible exposure to alcohol, drugs, medications and environmental toxins.

Because the families work and live on farms, pesticides top the list of suspects. More than 30 - some highly toxic and known to cause birth defects - were used in the tomato field where the mothers and fathers worked.

``Real-life situations are often a nightmare for scientists because people are exposed to dozens of chemicals in a single day, let alone the potential hundreds or even thousands they may encounter in a single pregnancy,'' Solomon said.

They also pose a challenge for lawyers trying to establish cause and effect in the courtroom - but it can be done.

In 1996, Miami attorney James Ferraro won a jury award of $4 million on behalf of John Castillo Jr.

Castillo's mother was sprayed with the DuPont fungicide Benlate in 1989 as she walked past a neighborhood strawberry field. She was seven weeks pregnant.

Months later, Donna Castillo gave birth to a boy with no eyes.

Ferraro presented studies at trial that showed rats exposed to Benlate's active ingredient were born with malformed eyes.

The jury's verdict and award were upheld last summer by the state Supreme Court.

It would not be feasible to hold the manufacturer of a pesticide liable for birth defects in a case like the one in Immokalee, Ferraro said.

``It's very different when you've got 30 different chemicals and a different mode of action for each one,'' he said.

However, the state Supreme Court decision in the Castillo case could pave the way for a lawsuit against the farm, Ferraro said.

``You can just show, in general, that some or all of those pesticides can cause that type of birth defect,'' he said. ``To go after the manufacturer, you would have to show which one it was.''

State agriculture department records show Ag-Mart has been issued warning letters four times since 1999 for violating worker health standards.

The company has been cited for allowing workers to re-enter fields too soon after pesticides were applied; using a pesticide on an unauthorized crop; failure to maintain required pesticide application records or post required information in a central location; and improper training of a worker who applied pesticides.

``We consider all of those serious or we wouldn't have drawn up administrative actions against this company,'' said agriculture department spokesman Terry McElroy.

The company has declined to answer specific questions about the case posed by The Tampa Tribune and News Channel 8 but issued the following statement through spokeswoman Leslie Gwinn:

``Ag-Mart continues to take this matter very seriously and is cooperating fully with all regulatory agencies conducting investigations.''

The company also notes the state is investigating other possible causes of the birth defects.

McElroy said the agriculture department is working with county and state health workers to examine pesticide application records and is interviewing the families to determine whether they might have used agriculture chemicals for household pest control, where they get their drinking water and other possible exposure to harmful substances.

The investigation should be winding down in a matter of weeks, McElroy said.

Flawed System

Federal law delegates the task of discovering and reporting adverse effects to the chemical manufacturers, which critics cite as a major flaw in the system.

A lack of oversight and inadequate surveillance for cases of pesticide-related illness is another.

The state health department's birth defects registry also has its limitations.

The so-called ``passive registry'' collects information based on hospital discharges from across the state. The Immokalee babies are not yet listed on the state's registry and likely won't be until the end of summer, the end of the year or even next year.

``The data is not as current as we would like it to be. I would like to know immediately,'' Correia said.

The investigation was started after a reporter from the Palm Beach Post brought the birth defects to Collier health officials' attention.

That angers some farmworker advocates.

``If it happened in a bank and three tellers in the same bank gave birth to severely deformed children within a month and a half, there would be instantly an investigation,'' said Brian Bennett, director of the Guadalupe Mission in Immokalee. ``But for some reason, as with so many issues, farmworkers are not given that same consideration.''

And yet, farmworkers might be the proverbial canary in the coal mine due to their regular and often intense exposure to chemicals that permeate the fabric of modern life, especially in Florida.

Pesticides are routinely sprayed on lawns and in homes, schools and office buildings. The routes of potential exposure are limitless, and their toll is virtually unknown.

While pesticides used in suburban settings are less likely than agricultural chemicals to be associated with birth defects, some are linked to childhood cancers, such as brain tumors and leukemia.

Some studies have shown an elevated risk of birth defects not only for people who work on farms but also for residents of agricultural communities.

``Some of the research studies have been flawed by assuming that people who don't live on the farms haven't been exposed,'' said Natural Resources Defense Council's Solomon.

Even the best studies on birth defects have not been able to identify which pesticides are of the greatest concern, she said. And the interactions between these chemicals have not been defined.

The federal government has proposed a national children's health study to sort out these issues over a period of 21 years.

That's too long to wait, Mekdeci said.

``Nationally, we're looking at off-the-chart stuff: a 1,700 percent increase in children being served for autism between 1992 and 2002; 450,000 children born every year with structural birth defects.''

Schools are in a dither about students not being able to pass the FCAT, she said, ``but no one is looking at the fact that these kids are coming into the world with severe impairments that are making it tough for teachers to handle, tough for them to learn.

``For the U.S. Department of Education, these things are like a train coming down the track. One problem is, nobody wants to count it up and see what's coming.''

Jay Feldman of the National Coalition Against the Misuse of Pesticides says ignorance does not necessarily equate to bliss.

``What we know doesn't paint a good picture; what we don't know may paint an even worse picture.''

WFLA, Channel 8 reporter Yolanda Fernandez and Tribune researchers Angie Holan and Melanie O'Bannon contributed to this story. Reporter Jan Hollingsworth can be reached at (813) 865- 4436.

Keyword: Multimedia, to watch a News Channel 8 report on Carlitos.