## Facts

- Stephen Tim Neal, Sr. and Laura Neal lived in an apartment from September 1993 to February 1995, during which the unit had an ant infestation and was sprayed multiple times over several months.
- During the period of spraying, Laura Neal was pregnant and later gave birth to Stephen Tim Neal, Jr.
- Several months after birth, Neal, Jr. was diagnosed with malignant ependymoma (a malignant brain tumor) and died.
- The Neals alleged the apartment was repeatedly treated with Dursban, a pesticide containing chlorpyrifos, manufactured/distributed/supplied by Dow-related defendants.
- The Neals asserted that repeated exposure to chlorpyrifos caused Laura’s injuries and caused Neal, Jr.’s brain tumor and death, pursuing multiple tort and statutory theories, including wrongful death.

## Issues

1. Whether the trial court abused its discretion by excluding the Neals’ medical causation expert’s opinion that exposure to Dursban/chlorpyrifos caused Neal, Jr.’s malignant ependymoma.
2. Whether, after exclusion of that expert causation evidence, Dow was entitled to no-evidence summary judgment on causation under Texas Rule of Civil Procedure 166a(i).

## Decision

- The court of appeals affirmed the trial court’s rulings.
- The trial court did not abuse its discretion in striking the expert’s causation testimony linking chlorpyrifos/Dursban to Neal, Jr.’s ependymoma.
- Because the Neals lacked admissible evidence raising a fact issue on causation after the exclusion, the no-evidence summary judgment for Dow was proper.

## Legal Principles

- Under Texas Rule of Civil Procedure 166a(i), a no-evidence summary judgment is proper when the nonmovant fails to produce more than a scintilla of probative evidence on a challenged essential element.
- Admissibility of expert testimony is reviewed for abuse of discretion; the proponent must establish the testimony is reliable and based on a sound methodology reliably applied to the case facts.
- An expert opinion may be excluded when there is an excessive analytical gap between the cited data (including scientific literature) and the causation conclusion offered.
- In toxic-exposure/product cases, causation proof must reliably connect the specific chemical/product at issue to the specific injury claimed; generalized associations or inconclusive studies are insufficient to support a definitive “more likely than not” causation opinion.

## Conclusion

The appellate court upheld exclusion of the plaintiffs’ sole medical causation expert as unreliable because the cited studies did not support the specific causal link asserted, and it affirmed no-evidence summary judgment because, without admissible expert evidence, the plaintiffs could not raise a genuine fact issue on causation.


Neal v. Dow Agrosciences LLC, 74 S.W.3d 468 (Tex. App.—Dallas 2002)