## Facts

- Milton Cecil Watts, a mechanic and later locomotive worker, was diagnosed in 1999 with small-cell lymphocytic lymphoma (a subtype of non-Hodgkin’s lymphoma).
- Watts testified he used the penetrating oil product “Liquid Wrench” beginning in the late 1940s and frequently between 1953 and 1961, sometimes for hours in unventilated spaces.
- From 1970 until retiring in 1996, Watts worked on locomotives and used Liquid Wrench regularly.
- At the relevant time, Liquid Wrench contained a solvent “raffinate” that contained benzene; the raffinate was supplied by United States Steel Corporation to Radiator Specialty Company.
- To prove causation, Watts presented expert testimony from Dr. Levy (epidemiology/occupational medicine) to establish both general causation (benzene can cause non-Hodgkin’s lymphoma) and specific causation (Watts’s exposure caused his lymphoma), relying mainly on a review of 18 epidemiological studies.
- Defendants challenged reliability, arguing the studies showed mixed results, did not examine Liquid Wrench or comparable exposures, and did not support Dr. Levy’s disease- and dose-specific causal conclusions.

## Issues

1. Whether the trial court abused its discretion under Mississippi Rule of Evidence 702 (Daubert-type reliability framework) by determining that Dr. Levy’s causation opinions were scientifically unreliable and should have been excluded.
2. Whether, after exclusion of the causation expert testimony, the evidence was legally insufficient to support causation, justifying judgment notwithstanding the verdict (JNOV) and dismissal with prejudice.

## Decision

- The Mississippi Supreme Court affirmed the trial court’s JNOV for Radiator Specialty Company and United States Steel Corporation and the dismissal with prejudice.
- The court held the trial court acted within its discretion in concluding Dr. Levy’s causation testimony was unreliable and inadmissible under Rule 702.
- The court held that, without admissible expert causation evidence, Watts could not prove causation in a complex toxic-tort case; therefore, the jury verdict could not stand and JNOV was proper.

## Legal Principles

- Under Mississippi Rule of Evidence 702, expert testimony must be relevant and based on reliable principles and methods reliably applied to the case facts; trial courts act as gatekeepers for scientific evidence.
- Appellate review of expert-admissibility rulings is deferential; the ruling stands unless arbitrary and clearly erroneous.
- In toxic-tort cases involving medically complex causation questions, plaintiffs generally must present admissible expert testimony on causation; lay jurors cannot infer causation without it.
- Epidemiological literature may support causation opinions, but the expert must show a reliable methodological basis linking the literature to the plaintiff’s disease and exposure, including addressing mixed statistical findings and exposure/dose comparability.
- When the plaintiff’s proof of causation depends on inadmissible expert testimony, exclusion can render the evidence legally insufficient, supporting JNOV.

## Conclusion

The court affirmed JNOV because the plaintiff’s epidemiology-based expert causation opinion lacked a reliable methodological foundation under Rule 702, and without admissible expert testimony the plaintiff could not establish causation for an alleged benzene-related lymphoma.


Watts v. Radiator Specialty Co., 990 So. 2d 143 (Miss. 2008)