In City of Cedarburg Light and Water Commission v. Allis-Chalmers Mfg. Co., 33 Wis.2d 560, 568B, 149 N.W.2d 661, 662 (1967), the Wisconsin Supreme Court recognized that “[t]here may be cases where the issue of causation, like the issue of negligence, involves technical, scientific or medical matters which are beyond the common knowledge or experience of jurors.” Id. at 568B, 662 (on rehearing). In such cases, the relevant inquiry on appeal is whether there is “at least a minimal sufficiency of expert testimony and lay testimony on causation to support the finding the jury made.” Id.

In determining whether sufficient evidence supports a jury’s verdict, “the test is whether there is any credible evidence in the record on which the jury could have based its decision. The evidence is viewed in the light most favorable to sustain the verdict; we do not look for credible evidence to sustain a verdict the jury could, but did not, reach.” Sumnicht v. Toyota Motor Sales, U.S.A., Inc., 121 Wis.2d 338, 360, 360 N.W.2d 2, 12 (1984). In determining causation, the jury must decide “whether the conduct at issue was a substantial factor in producing the injury.” Cavanaugh v. Andrade, 202 Wis.2d 290, 306, 550 N.W.2d 103, 110 (1996). An appellate court must sustain the jury’s finding on causation “if there is any credible evidence under any reasonable view or any reasonable inferences derived therefrom that support [it].” Id. (citations omitted); see also Wausau Underwriters Ins. Co. v. Dane County, 142 Wis.2d 315, 326, 417 N.W.2d 914, 918 (Ct. App. 1987) (“When an appellant proposes that we change a jury’s answers on causation, we are to view the evidence in the light most favorable to the verdict and determine if the verdict is supported by any credible evidence.”).

Mrs. Anderson presented expert testimony linking the asbestos from Combustion Engineering’s products with the malignant mesothelioma that caused her husband’s death. This expert testimony, coupled with the fact witnesses who testified about Mr. Anderson’s exposure to asbestos from Combustion Engineering boilers, strongly supports the jury’s causation finding.


Mr. Anderson was initially diagnosed with mesothelioma by his treating physician, Dr. Margery Howard. R.310, 11/9/2000, Trial Tr. at 9-10. Dr. Howard is a board-certified oncologist based at St. Luke’s Hospital in Milwaukee. R.310, 11/9/2000, Trial Tr. at 4-5, 8-9. Dr. Howard’s diagnosis was confirmed by the initial findings at Mr. Anderson’s autopsy. R.310, 11/9/2000, Trial Tr. at 14-15, 17. The pathologist who performed the autopsy then sent tissue samples to Dr. Victor Roggli, a specialist in lung pathology at Duke University. R.310, 11/9/2000, Trial Tr. at 15-16. Dr. Roggli’s tests confirmed the diagnosis of mesothelioma and quantified the asbestos bodies in Mr. Anderson’s lung tissue. R.310, 11/9/2000, Trial Tr. at 18.

Dr. Roggli, a board-certified pathologist, testified at trial to explain his findings. <cite> Dr. Roggli is a widely recognized expert on asbestos-related diseases such as mesothelioma. His published research has focused on issues related to asbestos, such as identifying the types of asbestos fibers that cause mesothelioma and correlating the amount of asbestos in lung tissue with the nature and duration of occupational exposure. R.310, 11/9/2000, Trial Tr. at 64-65. In addition to publishing his research in peer-reviewed medical journals, Dr. Roggli is the lead author of a textbook called Pathology of Asbestos-Associated Diseases. R.310, 11/9/2000, Trial Tr. at 66. He is one of only seven physicians in the United States to serve on the U.S./Canadian Mesothelioma Panel, which serves as an international referral panel for pathologists. R.310, 11/9/2000, Trial Tr. at 68.

Dr. Roggli explained the different types of asbestos fibers and their connection to mesothelioma. The primary fiber types are chrysotile, amosite and crocidolite. R.310, 11/9/2000, Trial Tr. at 103. Dr. Roggli testified that amosite was the most common type of asbestos found in the lungs of workers who were exposed to asbestos-containing materials from boilers. R.310, 11/9/2000, Trial Tr. at 117. Dr. Roggli also explained the process by which these asbestos fibers are inhaled into the lungs, carried out to the alveoli and into the pleura, the lining of the chest cavity. In some cases, such as Mr. Anderson’s, the fibers interact with the lining of the pleura, the mesothelium. A tumor is formed and eventually encases the lung, a type of cancer known as mesothelioma. R.310, 11/9/2000, Trial Tr. at 83-84.

Most people have very low levels of asbestos in their lung tissue, ranging between zero and 20 asbestos bodies per gram of wet lung tissue. R.310, 11/9/2000, Trial Tr. at 85-86. In Mr. Anderson’s lung tissue, Dr. Roggli found 3,040 asbestos bodies per gram of wet lung tissue. R.310, 11/9/2000, Trial Tr. at 96-97. Most of the asbestos fibers in Mr. Anderson’s lung were amosite, the type associated with boiler exposures. R.310, 11/9/2000, Trial Tr. at 100, 117.

Based on his findings, Dr. Roggli concluded to a reasonable degree of medical and scientific certainty that Mr. Anderson died from mesothelioma caused by his prior exposure to asbestos. R.310, 11/9/2000, Trial Tr. at 111-12. In cross-examination, Combustion Engineering asked Dr. Roggli: “You are aware of the fact that the majority of asbestos-containing products sold commercially in the United States were amosite, correct?” R.310, 11/9/2000, Trial Tr. at 128. Dr. Roggli was not aware of this “fact,” because there is no such fact. Dr. Roggli responded, correctly, that the majority of the products contained chrysotile asbestos. Id. Dr. Roggli was entirely correct on this point, and Combustion Engineering was wrong. It is a historical fact that approximately 90 percent of the asbestos commercially used in the United States was chrysotile. See, e.g., 48 F.R. 51086, 51114 (1983).[1] After correcting Combustion Engineering’s factual error, Dr. Roggli did not press the point and said he would be willing to defer to a qualified industrial hygienist on the question. R.310, 11/9/2000, Trial Tr. at 128. The question is somewhat academic, since there were no practicing industrial hygienists called at trial. Combustion Engineering called Dr. J. LeRoy Balzer, who is not a certified industrial hygienist and has not been one since 1988. R.315, 11/20/2000, Trial Tr. at 106-07. In any case, Dr. Balzer did not dispute Dr. Roggli’s testimony. Indeed, contrary to Combustion Engineering’s representations, Dr. Balzer did not testify about causation at all.

Dr. Balzer is not a medical doctor. R.315, 11/20/2000, Trial Tr. at 108. He is not qualified to determine the cause of Mr. Anderson’s mesothelioma, as he admitted in cross-examination:

Q. Are you testifying today that Jerry [Anderson] did not have mesothelioma?

A. No, that is a medical question.

Q. Are you testifying that asbestos did not cause Jerry [Anderson’s] mesothelioma?

A. I’m not, no.

Q. Are you testifying that any company’s asbestos specifically caused Mr. Anderson’s mesothelioma?

A. No, I’m not testifying to that.


Q.Are you offering any opinion as to whether or not the defendant’s asbestos played any role in causing Jerry [Anderson’s] mesothelioma?


R.315, 11/20/2000, Trial Tr. at 142-43 (emphasis added). Had Dr. Balzer sought to offer opinions on the causation of Mr. Anderson’s illness, he would have been far outside the scope of his qualifications. See Leahy v. Kenosha Memorial Hosp., 118 Wis.2d 441, 453, 348 N.W.2d 607, 614 (Ct. App. 1984) (questioning whether nurse was qualified to “render medical opinions relating to diagnosis, causation and permanency”).

Dr. Balzer addressed the narrower issue of whether Mr. Anderson was exposed to levels of asbestos that exceeded a historical industry standard called the “Threshold Limit Value” or “TLV.” Dr. Balzer testified in support of Combustion Engineering’s argument that its products were not defective because they did not produce dust in excess of this TLV. R.315, 11/20/2000, Trial Tr. at 99. Dr. Balzer testified that he thought Mr. Anderson’s exposure to asbestos from Combustion Engineering’s boilers was below the TLV.[2] Even accepting Dr. Balzer’s testimony as true, it has nothing to do with causation. As Dr. Balzer himself admitted, the TLV is not calculated to protect against mesothelioma. R.315, 11/20/2000, Trial Tr. at 115-16; see also R.308, 11/7/2000, Trial Tr. at 11. The undisputed medical testimony established that mesothelioma is caused by relatively low levels of exposure to asbestos. See, e.g., R.309, 11/8/2000, Trial Tr. at 53-56.

Indeed, it is unclear whether the TLV was ever effective in protecting against any asbestos-related disease. Dr. David Egilman, a physician specializing in occupational medicine, has researched the development of the TLV for asbestos. He testified that the TLV has never represented a “safe” level of exposure. R.308, 11/7/2000, Trial Tr. at 11. As early as the 1930s, scientists questioned whether the TLV was really protective against disease. R.308, 11/7/2000, Trial Tr. at 20-21 As Dr. Egilman has documented in his published articles, the concept of a TLV for asbestos was developed by asbestos companies as a tool for defending against personal injury suits. R.309, 11/8/2000, Trial Tr. at 197-98. Whatever the merits of the TLV as a legal strategy, it has nothing to do with the medical question of what caused Mr. Anderson’s mesothelioma.

As discussed above, the undisputed medical testimony established that mesothelioma can be caused even by relatively low exposures to asbestos. The other evidence at trial established that Mr. Anderson was in fact exposed to large amounts of asbestos dust from Combustion Engineering’s boilers. Tom Mlinar, one of Mr. Anderson’s co-workers, testified that the process of removing panels on the boilers produced dust to thick he could not see someone a foot away. R.310, 11/9/2000, Trial Tr. at 165-66. Cutting these panels would produce “very dusty” conditions “right next to” Mr. Anderson. R.310, 11/9/2000, Trial Tr. at 178. Mr. Anderson was exposed to dust while making repairs over and under the boilers. R.310, 11/9/2000, Trial Tr. at 179-83. Mr. Mlinar recalled Mr. Anderson telling him to “keep that damned dust up there” while working on the boiler. R.310, 11/9/2000, Trial Tr. at 184.

Don Hakes, another of Mr. Anderson’s co-workers, explained that the asbestos dust from the boilers would filter through gratings dozens of feet down into the machine shop, where Mr. Anderson worked. R.310, 11/9/2000, Trial Tr. at 231-32. Boilermakers pulling out panels would yell “look out below” as insulation dust fell on the machinists. R.312, 11/10/2000, Trial Tr. at 44.

Dr. Egilman explained the significance of such occupational exposures. Dr. Egilman has been trained to evaluate plant exposures. R.308, 11/7/2000, Trial Tr. at 43; R.309, 11/8/2000, Trial Tr. at 44-46. He consults for companies seeking to design safer workplaces and reduce hazardous exposures and has served as a medical officer for the National Institute for Occupational Safety and Health. R.308, 11/7/2000, Trial Tr. at 52; R.308, 11/7/2000, Trial Tr. at 40-41. Based on this training and experience, Dr. Egilman discussed the ways in which workers such as Mr. Anderson are exposed to hazardous levels of asbestos.

Workers are exposed to asbestos when they inhale dust from asbestos-containing products. R.308, 11/7/2000, Trial Tr. at 27-31. Drawing on several decades of scientific research, Dr. Egilman explained that this dust can move throughout a plant, making it essential to isolate the processes that produce dust. R.308, 11/7/2000, Trial Tr. at 48-51. Working near boilers, as Mr. Anderson did, increases the risk of developing diseases such as mesothelioma. R.309, 11/8/2000, Trial Tr. at 51-52. Indeed, data from Combustion Engineering’s own plant in Pennsylvania demonstrated that people working around boilers were exposed to asbestos. R.309, 11/8/2000, Trial Tr. at 65-66.

Rather than addressing the testimony that was actually presented at trial, Combustion Engineering devotes much of its argument to a witness who never took the stand. Mrs. Anderson’s attorneys initially designated an industrial hygienist named William Ewing as a witness, but they notified Combustion Engineering well before trial that they did not intend to call Mr. Ewing in their case in chief and “probably not call him at all.” R.315, 11/20/2000, Trial Tr. at 10. Mr. Ewing would only be called in rebuttal if Dr. Balzer testified to matters outside the scope of his deposition. R.158, Letter dated 9/25/2000 (emphasis in original). Dr. Balzer did not do so, and Mr. Ewing’s rebuttal testimony proved unnecessary. Mrs. Anderson’s counsel informed Combustion Engineering that Mr. Ewing was not asked to prepare any opinions for trial and that if he were deposed, his answer to most substantive questions would therefore be “I don’t know.” R.158, Letter dated 9/25/2000. Nevertheless, Combustion Engineering insisted on deposing Mr. Ewing. To the surprise of no one, Mr. Ewing’s answer to most substantive questions was “I don’t know.” Combustion Engineering refers to these deposition excerpts repeatedly but never explains how a jury’s verdict can be set aside based on testimony that was never presented at trial.

The evidence that actually was presented at trial, which Combustion Engineering largely ignores, does establish that Combustion Engineering’s products were a substantial factor in causing Mr. Anderson’s mesothelioma. Combustion Engineering takes the position that the medical and scientific testimony presented by Mrs. Anderson cannot support a finding of causation, but there is no support for Combustion Engineering’s position. In fact, most occupational exposure cases rely primarily on medical testimony in evaluating causation.

For example, in Kimberly-Clark Corp. v. Labor and Industry Review Commission, 138 Wis.2d 58, 405 N.W.2d 684 (Ct. App. 1987), two physicians attributed an employee’s hearing loss to occupational noise exposure. Id. at 67, 689. Against this medical testimony, the employer offered “noise level surveys” taken by an industrial hygienist, which showed noise levels below the threshold levels set in the Administrative Code. Id. at 61-68, 686-89. This Court held that the industrial hygiene surveys were not even sufficient to raise a question about the physician’s medical conclusions and held that the employer’s denial of benefits constituted bad faith. Id.; see also Maynard Elec. Steel Casting Co. v. Industrial Commission, 273 Wis. 38, 42-46, 76 N.W.2d 604, 606-08 (1956) (reviewing testimony of physicians and concluding that medical testimony supported finding that employee’s “heavy dust exposure” caused his silicosis). Significantly, the statute governing workers’ compensation for toxic exposures requires a “competent medical opinion”and provides for a medical examination but does not require any other form of expert testimony. W.S.A. § 102.565(1). Like courts in virtually every other jurisdiction, Wisconsin courts rely on medical testimony to evaluate causation in toxic exposure cases.

Mrs. Anderson presented direct testimony about her husband’s exposure and expert testimony linking that exposure to his fatal disease. This evidence strongly supports the jury’s finding on causation.


Combustion Engineering argues separately that expert testimony was required to assist the jury in apportioning fault among the various joint tortfeasors. As discussed above, the jury heard extensive testimony from both expert and fact witnesses on the nature, extent and duration of Mr. Anderson’s exposure to asbestos from different sources and the connection between that exposure and his disease. This evidence provided a reasonable basis for the jury to apportion fault. The jury’s apportionment of fault requires an evaluation of the conduct of the parties and the circumstances of the case. It is not, as Combustion Engineering suggests, an exercise in applying rigid numerical formulas. As the supreme court has explained:

The apportionment of negligence is the peculiar province of the jury. The degree of negligence attributable to a party is not to be measured by the character thereof nor by the number of respects in which he is found to have been at fault. It is the conduct of the parties considered as a whole which should control. In other words, once it has been established that each has been negligent, it is then the jury’s function to weigh their respective contributions to the result, which will, regardless of the nature of their acts or omissions, determine which made the larger contribution and to what extent it exceeds or is less than that of the other.

Collins v. Eli Lilly Co., 116 Wis.2d 166, 199, 342 N.W.2d 37, 53 (Wis. 1984) (quoting Taylor v. Western Casualty & Surety Co., 270 Wis. 408, 411-12, 71 N.W.2d 363 (1955)).

Even if Combustion Engineering were correct in arguing that additional expert testimony was required on the apportionment of fault, the burden was on Combustion Engineering to present such testimony at trial. A plaintiff has the burden of showing that the defendant’s conduct was a substantial factor in causing the injury. As discussed above, Mrs. Anderson met that burden. If a defendant seeks to reduce its liability by attributing fault to the plaintiff or other parties, the defendant bears the burden of proof. See McGuiggan v. Hiller Bros., 253 N.W. 403, 405 (Wis. 1934) (“Under the comparative negligence law the burden of proving the total amount of the damages sustained is upon the plaintiff, but the burden of showing to what extent the damages sustained by the plaintiff shall be diminished on account of the negligence attributable to him is upon the defendant.”). It is widely recognized that the burden of apportioning fault among tortfeasors rests on the party seeking apportionment, usually the defendant. See, e.g., Piner v. Superior Court, 962 P.2d 909, 916 (Ariz. 1998); McGraw v. Sanders Co. Plumbing and Heating, Inc., 667 P.2d 289, 296 (Kan. 1983).

If Combustion Engineering believed that expert testimony was necessary to apportion fault, then Combustion Engineering should have presented such testimony at trial. Combustion Engineering certainly cannot seek reversal based on shortcomings in its own evidence. See Engel v. Dunn County, 273 Wis. 218, 222, 77 N.W.2d 408, 410 (Wis. 1956) (“If appellant was dissatisfied with damages based on cost of repairs it might show, if such was the fact, that diminution of value was a smaller sum. The absence of such evidence does not render evidence of cost of repairs insufficient to support a finding of damage in that amount.”).

In reality, there was not an “absence” of expert testimony as to the apportionment of fault. Experts from both sides discussed the degree of exposure Mr. Anderson sustained from different sources. It was the jury’s role to weigh this expert testimony and apportion fault accordingly. Jurors are not required to give “controlling influence” to any particular expert testimony and “may consider it along with other testimony and arrive at their independent judgment on the facts.” Anderson v. Eggert, 234 Wis. 348, 291 N.W. 365, 371 (1940). Combustion Engineering has shown no basis for setting aside the jury’s decision on apportionment of fault or any other issue. The judgment should be affirmed.

  1. This Court may take judicial notice of the contents of the Federal Register. 44 U.S.C. § 1507; W.S.A. § 902.03(2).
  2. The basis for Dr. Balzer’s opinions remains somewhat unclear. He admitted that he cannot accurately quantify past exposures and that he did not observe conditions at Oak Creek during the relevant time frame. R.315, 11/20/2000, Trial Tr. at 108, 143-44. His conclusions appear to be based on selected deposition testimony and other information provided by Combustion Engineering’s attorneys. See R.315, 11/20/2000, Trial Tr. at 117-19, 121-22, 133-34.