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

Daubert Standard: Did Plaintiff Prove that Diesel Exhaust Causes Multiple Myeloma?

The primary disputed issue in this case is whether there was any scientifically reliable evidence to support a finding that Manuela Navarro’s bone marrow cancer was caused by any chemical components of diesel exhaust in the air at the Laredo rail yard and bridge facility. In this case the plaintiff’s experts concluded that diesel exhaust causes multiple myeloma. No reputable scientist has to our knowledge come to that conclusion or made that assertion in any published article, monograph, study or textbook. The fact is that the scientific community does not know what causes multiple myeloma. The notion that judicial liability can diverge from scientific knowledge was condemned in Daubert v. Merrell Dow Phar., Inc., 509 U.S. 579 (1993), and in Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706 (Tex. 1997), and other recent cases.

Manuela Navarro performed different functions — as messenger, way bill clerk, yard clerk, janitor, demurrage clerk, etc., for Union Pacific for twenty years as a part-time employee; she worked part of the time outside, either in the Laredo rail yard or as a messenger, and part of the time in the freight office. In April, 1994, Mrs. Navarro was diagnosed with multiple myeloma, a rare cancer of the bone marrow. Mrs. Navarro’s had a family history of and she was diagnosed with diabetes in 1988.

After her diagnosis of multiple myeloma, Mrs. Navarro sued, alleging that her cancer had been caused either by unknown hazardous chemical residues which originated in empty tank cars or else by diesel exhaust in the air at the Laredo rail yard, or both. No evidence was offered as to exposure to hazardous chemicals, and this theory was not submitted to the jury.

Plaintiff’s “experts” — Frank Parker, an industrial hygienist, Dr. Hari Dayal, an epidemiologist, Dr. Frank Gardner, an oncologist, and Dr. Marvin Legator, a toxicologist — never had done any research about diesel exhaust or its relationship to multiple myeloma before they were retained for this lawsuit.

Issue Areas:

Sound Science

Read the Amicus Brief:
Question(s) Presented:

Did the Trial Court err in admitting the unsupported conclusions of the Plaintiff’s expert witnesses?


Additional Background:

Several of the amici submitted a brief in the Supreme Court in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), the seminal case discussing the rule for admissibility of expert scientific evidence. Amici support the principles enunciated by the Supreme Court in that case, and by the Supreme Court of Texas in E.I. du Pont de Nemours & Co. v. Robinson, 923 S.W.2d 549 (Tex. 1995) and in Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706 (Tex. 1997).

ALF’s Amicus Brief:

Amici submit that the methodology used by the plaintiff’s experts in this case is not scientifically sound. In this case the plaintiff’s experts concluded that diesel exhaust causes multiple myeloma. No reputable scientist has to our knowledge come to that conclusion or made that assertion in any published article, monograph, study or textbook. The fact is that the scientific community does not know what causes multiple myeloma. The notion that judicial liability can diverge from scientific knowledge was condemned in Daubert v. Merrell Dow Phar., Inc., 509 U.S. 579 (1993) and in Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706 (Tex. 1997), and other recent cases.

The problem starts with Frank Parker’s speculative opinion as to Mrs. Navarro’s exposure to diesel exhaust. Mr. Parker’s estimate of exposure forms the underlying basis of the opinions of the other plaintiff’s experts that Mrs. Navarro’s multiple myeloma was caused by diesel exhaust. Mr. Parker’s estimate is contradicted by actual data collected at the Laredo rail yard; that data showed that railroad workers at that yard were not exposed to elevated levels of harmful chemicals in diesel exhaust. Mr. Parker’s testimony that Mrs. Navarro was exposed to 128 to 233 micrograms per cubic meter (μg/m3) of diesel exhaust was a radical departure from his original estimate of exposure — 7.2 μg/m3 – which is close to the amount actually measured at the Laredo rail yard, and was arrived at by using exposure estimates for “hostlers” and “brakers,” (who work outdoors in the rail yard) not clerks like Mrs. Navarro, who work primarily indoors, based solely on one table in a 1988 study of railroad workers, and by ignoring numerous other factors that would tend to reduce Mrs. Navarro’s actual exposure.

The opinions of Dr. Dayal, an epidemiologist, Dr. Frank Gardner, an oncologist, and Dr. Marvin Legator, a toxicologist, should not have been admitted in evidence because: (1) they were based upon Frank Parker’s scientifically inaccurate exposure estimate; (2) they were not supported by scientifically reliable methodology; (3) they were not supported by independent scientific research; and (4) they were not supported by any scientifically sound data, theory, or methodology.

Plaintiff did not satisfy his burden of meeting the admissibility standards set forth in Robinson and Havner. If the trial court had applied the governing Texas standards for admissibility of expert testimony, it would have excluded plaintiff’s unreliable causation testimony. Amici ask this Court to reverse the court below.

Status:

On June 26, 2002, the Court issued a favorable opinion.

Date Originally Posted: November 25, 2001

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