graphic image depicting green amicus briefs for Atlantic Legal Foundation Amicus Brief Summary

Daubert in Florida: When to “Trust the Science”

This case arises from the tragic fact that a child was born with microphthalmia, a birth defect involving severely underdeveloped eyes. But this case also involves the application of principles and methods of sound science to the adjudication of legal claims and important issues of allocation of legal liability.
Plaintiffs brought claims against DuPont, the manufacturer of the agricultural fungicide Benlate and the owner of a farm at which the fungicide was allegedly sprayed while the child’s mother, who was pregnant with John at the time, was in the vicinity, alleging that the fungicide had been sprayed on a field at the farm as the mother walked by, and that the mother’s exposure to the fungicide caused the child’s birth defect. Plaintiffs’ case was based on the theory that the mist sprayed in the field, to which Mrs. Castillo had allegedly been exposed, contained Benlate, and that benomyl (the active ingredient in Benlate) entered her bloodstream and caused John’s microphthalmia.

In support of their theory of liability, and as their sole causation evidence, plaintiffs proffered the expert testimony of Dr. Charles Vyvyan Howard. Dr. Howard testified, in pretrial deposition, that he believed that fetal exposure to benomyl at a concentration of twenty parts per billion in the maternal bloodstream would cause microphthalmia in humans. Dr. Howard based his conclusion on: 1) rat gavage studies and 2) lab experiments on human and rodent cells in vitro.
Defendants moved in limine to exclude Dr. Howard’s testimony on the ground that his opinion is not based on scientific principles and discoveries that are generally accepted in the field” of teratology, and thus inadmissible. After an evidentiary hearing, the trial court denied that motion and permitted Dr. Howard to testify to his opinion that benomyl is a human dermal teratogen that at fetal tissue levels of 20 parts per billion caused the birth defect microphthalmia in John Castillo.

At trial, plaintiffs claimed that a single incident, in which Mrs. Castillo was allegedly “drenched” with Benlate spray, caused John Castillo’s birth defect. At the close of the evidence, DuPont moved for a directed verdict arguing that plaintiffs had failed to prove that Benlate is defective and that any such defect proximately caused John’s microphthalmia. The jury found for plaintiffs. DuPont and Pine Island moved to set aside the verdict and/or for a new trial, which motion the trial court denied. The Third District Court of Appeals reversed and remanded the case for entry of judgement on behalf of DuPont. This Court granted Petitioners’ Petition for Discretionary Review.

Issue Areas:

Sound Science

Read the Amicus Brief:
Question(s) Presented:

Whether plaintiff’s primary expert witness’ testimony was admissible.

Additional Background:

Amici are teratologists, and thus members of the specialized medical community most germane to the scientific issues in this case. The credentials of amici are described in the Biographical Addendum to this brief. They seek to inform the Court of the elements of the generally accepted methodology for determining human teratogenicity. Amici address whether Dr. Charles Vyvyan Howard, plaintiffs’ expert witness, employed generally accepted methodology in arriving at his opinion, and we respectfully submit that the methodology employed by Dr. Howard is an unscientific departure from what is generally accepted in the fields of teratology and medical genetics.
Amici’s interest in this litigation derives from a concern that courts in the United States adopt appropriate and scientifically based methodologies. Amici submit this brief in support of Respondent DuPont.

ALF’s Amicus Brief:

Amici have reviewed Dr. Howard’s testimony, and believe that Dr. Howard’s analysis and methodology are not generally accepted among teratologists and epidemiologists, and that they are not scientifically sound. Amici agree with the District Court of Appeal that plaintiffs’ scientific evidence should never have been admitted into evidence because it did not satisfy the test for admissibility set forth in Frye v. United States, 293 F. 1013 (D.C. Cir. 1923).

There is a generally accepted methodology in the field of teratology for determining whether a substance is a human teratogen. That methodology requires:
1. a specific pattern of birth defects across individuals that is associated with exposure;
2. epidemiological studies showing an association between exposure and birth defects;
3. positive cross-species test results at equivalent doses and by the same route of exposure as human exposure to establish a dose-response relationship;
4. in vitro tests used to identify a mechanism of action; and
5. biological plausibility that the mechanism of action could cause the
pattern of birth defects observed.
Dr. Howard did not follow this methodology, therefore his testimony was inadmissible. Amici ask this Court to affirm the appeals court.




On July 10, 2003, the Florida Supreme Court issued an adverse decision.

Date Originally Posted: November 6, 2000

Scroll to Top