## Facts

- Residents and property users near a natural gas compressor station in Lobelville, Tennessee alleged environmental releases of PCB-contaminated condensate from compressor operations.
- Plaintiffs claimed the defendants used a lubricant (Pydraul AC) contaminated with PCBs, resulting in PCB contamination of surrounding air, water, and soil.
- Plaintiffs brought personal injury claims alleging that PCB exposure caused various health problems.
- Plaintiffs’ medical causation proof primarily relied on two experts, Dr. Kaye H. Kilburn and Dr. Alan R. Hirsch.
- Defendants moved to exclude the experts under Federal Rule of Evidence 702 and Daubert; the trial court excluded both experts as unreliable.
- With expert causation testimony excluded, the trial court granted summary judgment to defendants on all personal injury claims and denied plaintiffs’ post-judgment motion seeking reconsideration and an opportunity to present different experts.

## Issues

1. Whether the trial court abused its discretion under Federal Rule of Evidence 702 and Daubert by excluding plaintiffs’ medical causation experts as methodologically unreliable.
2. Whether the trial court abused its discretion by ruling without an evidentiary Daubert hearing and by refusing to allow plaintiffs to substitute new experts after exclusion.

## Decision

- The Sixth Circuit affirmed the exclusion of Drs. Kilburn and Hirsch under Rule 702 and Daubert.
- The court held the trial court did not abuse its discretion in finding the experts’ causation methodologies unreliable, including for failing to connect plaintiffs’ exposure to harmful PCB dose levels and for insufficiently addressing alternative causes.
- The Sixth Circuit affirmed summary judgment because, without admissible expert causation evidence, plaintiffs could not raise a genuine dispute of material fact on medical causation.
- The court affirmed the denial of an evidentiary hearing, holding that a Daubert hearing is not required in every case and the record permitted decision on written submissions.
- The court affirmed denial of plaintiffs’ request to present new experts after exclusion, rejecting a post-exclusion “second chance” where plaintiffs had adequate opportunity to develop admissible expert proof.

## Legal Principles

- Trial courts act as gatekeepers under Federal Rule of Evidence 702 and Daubert and may exclude expert testimony that lacks reliable scientific methodology.
- In toxic tort causation cases, reliable expert proof generally requires a scientifically supported link between exposure and injury, including evidence addressing dose/exposure levels and plausible alternative causes.
- Appellate review of Daubert admissibility rulings is for abuse of discretion, and substantial deference is given to the trial court’s reliability assessment.
- A Daubert evidentiary hearing is discretionary; a court may decide admissibility on the written record when it is sufficient.
- A court may deny a post-exclusion effort to reopen the case to add new experts, particularly when the party had a fair opportunity to present admissible expert evidence earlier.

## Conclusion

The Sixth Circuit held that the trial court permissibly excluded plaintiffs’ medical causation experts as unreliable under Rule 702 and Daubert, and that summary judgment properly followed because plaintiffs lacked admissible causation evidence; the court also upheld the refusal to hold a Daubert hearing and to permit new experts after exclusion.


Nelson v. Tennessee Gas Pipeline Co., 243 F.3d 244 (6th Cir. 2001)