1 COMMENT A DOSE OF REALITY: THE STRUGGLE WITH CAUSATION IN TOXIC TORT LITIGATION TABLE OF CONTENTS I. INTRODUCTION II. AN ASBESTOS PRIMER A. What Is Asbestos? B. The Signature Diseases C. A Brief History of Asbestos Litigation D. The Signature Problems III. LEGAL AND SCIENTIFIC PRINCIPLES OF TOXIC TORT CASES A. A Quick Toxicology Primer B. A Quick Tort Causation Primer C. Additional Causation Principles in Toxic Tort Litigation IV. HOW AND WHY DO ASBESTOS CASES DEPART FROM GENERAL TORT PRINCIPLES? A. Lohrmann: The Most Widely Used Causation Test in Asbestos Litigation B. Flores: The First Court of Last Resort Addresses the Lack of Dosage in Asbestos Litigation This Comment received the Shook, Hardy, and Bacon Award for Best Paper in the Area of Health Law. The Author would like to thank the fine editors of the Houston Law Review for their work in publishing this Comment; Professor Joseph Sanders for his guidance in selecting a topic; her family and Matt Savage for their enduring love and support throughout law school; and last, but certainly not least, Scott Armstrong and Joshua Lee, both of whom were substantial factors in her placement on the Houston Law Review and thus the production of this Comment. 1147
2 1148 HOUSTON LAW REVIEW [51:4 C. Rutherford: Introduction of the Concept of Increasing Risk of Asbestos-Related Diseases D. The Any-Exposure Theory: A Substantial Departure from Tort and Case Law V. A STARTING POINT FOR RECONCILIATION A. Exclude Inappropriate Expert Testimony That Supports Any-Exposure Theory B. Is a Dose of Reality Enough or Is It Too Much? VI. CONCLUSION I. INTRODUCTION Microscopic fibers, up to 1,200 times smaller than human hair, 1 wreak havoc in the human body 2 and the legal system. 3 These small fibers, collectively named asbestos, 4 led to a growing total of 730,000 lawsuits filed 5 with no projected end in sight. 6 Although it is unclear if asbestos litigation is in its final stages, 7 it is important to focus on the legal issues it presents. First, asbestos causes unique diseases that make the determination of the element of causation in plaintiff s tort 1. Examining the Human Health Effects of Asbestos and the Methods of Mitigating Such Impacts: Hearing Before the S. Comm. on Env t & Pub. Works, 110th Cong. 2 (2007) [hereinafter Asbestos Hearings] (statement of Sen. Barbara Boxer). 2. Id. 3. See SUMMARY OF THE REPORT OF THE JUDICIAL CONFERENCE: AD HOC COMMITTEE ON ASBESTOS LITIGATION 2 (1991) (describing asbestos litigation as a disaster of major proportions.... ). 4. U.S. GEOLOGICAL SURVEY, U.S. DEP T OF THE INTERIOR, USGS FACT SHEET FS , SOME FACTS ABOUT ASBESTOS (2001), available at /http://pubs.usgs.gov/fs/fs012-01/fs pdf. 5. STEPHEN J. CARROLL ET AL., ASBESTOS LITIGATION 70 (2005) [hereinafter CARROLL ET AL., ASBESTOS LITIGATION]. This estimate is the total amount of asbestos litigation filed as of 2002; it is likely more, but the exact figure is unknown. Id. at 71 72; see infra note 13 and accompanying text (discussing how state courts do not keep records as thoroughly or file cases by type as the federal courts). However, one researcher found that 1,598 out of more than one million claims went to trial. STEPHEN J. CARROLL ET AL., ASBESTOS LITIGATION COSTS AND COMPENSATION: AN INTERIM REPORT 56, 77 (2002) [hereinafter CARROLL ET AL., COSTS AND COMPENSATION]. Therefore, it is safe to assume that there have been at least one million asbestos claims filed. Id. at Joseph Sanders, Michael D. Green & William C. Powers, Jr., The Insubstantiality of the Substantial Factor Test for Causation, 73 MO. L. REV. 399, 401 (2008). 7. Id. One author submits that there are more than one million plaintiffs who have yet to file. CARROLL ET AL., COSTS AND COMPENSATION, supra note 5, at 78.
3 2014] A DOSE OF REALITY 1149 cases difficult. 8 To remedy these difficulties, some courts abandon traditional tort causation principles and allow plaintiffs to prove minimal exposure to a manufacturer s product rather than prove that the level of exposure actually caused the plaintiff s disease. 9 In these courts, plaintiffs rely on experts who regularly opine that any exposure is sufficient to cause a plaintiff s asbestos-related disease. 10 This is not consistent with traditional tort causation principles. 11 Second, even if the number of asbestos cases filed per year is declining, 12 the fact remains that the judicial system receives tens of thousands of case filings. 13 The acceptance or rejection of a certain causation theory in asbestos litigation can have a significant legal impact for both plaintiffs and defendants in pending cases, along with parties in cases that are not filed yet. 14 Additionally, whether a certain court accepts or rejects a 8. Sanders, Green & Powers, supra note 6, at ; see infra Part IV. 9. Mark A. Behrens & William L. Anderson, The Any Exposure Theory: An Unsound Basis for Asbestos Causation and Expert Testimony, 37 SW. U. L. REV. 479, (2008). 10. Id. at 487. For example, one expert testified, Each and every exposure to asbestos has been a substantial contributing factor to the abnormalities noted. Summers v. Certainteed Corp., 886 A.2d 240, 244 (Pa. Super. Ct. 2005), rev d, 997 A.2d 1152 (Pa. 2010). 11. Compare infra Part III (providing an overview of toxicology and tort causation principles), with infra Part IV (surveying the ways courts handle causation in asbestos cases). 12. For a brief discussion of reasons why asbestos case filings are down, see infra notes THOMAS F. HOGAN, ADMIN. OFFICE OF THE U.S. COURTS, JUDICIAL BUSINESS OF THE UNITED STATES COURTS: 2011 ANNUAL REPORT OF THE DIRECTOR 125 tbl.c-2 (2012). From September 30, 2009, to September 30, 2010, plaintiffs filed 41,133 asbestos-related civil cases in federal courts. Id. From September 30, 2010 to September 30, 2011, the number of asbestos-related cases filed in federal courts decreased slightly to 37,744. Id. Unfortunately, the exact number of asbestos cases nationwide is unknown because many state courts do not keep records of the types of cases filed. CARROLL ET AL., ASBESTOS LITIGATION, supra note 5, at 3. However, because federal courts handle a smaller amount of asbestos cases, it can be assumed that there are more than 100,000 in the judicial system. See id. (reporting that most lawsuits have been filed in state courts ); PUB. CITIZEN, ASBESTOS CASES IN THE COURTS: NO LOGJAM 9 (2006), available at (estimating that federal courts handle only twenty percent of the total amount of asbestos cases). 14. See supra notes 8 10 and accompanying text (discussing the accommodations that courts make for plaintiffs that file asbestos suits to prove causation). See generally infra Part IV (canvassing the different tests that jurisdictions use to help solve causation problems for plaintiffs filing asbestos claims). Asbestos-related diseases typically do not manifest themselves until decades after exposure to asbestos-containing products. Thomas A. Sporn & Victor L. Roggli, Mesothelioma, in PATHOLOGY OF ASBESTOS- ASSOCIATED DISEASES 104, (Victor L. Roggli et al. eds., 2d ed. 2004). There might be a new wave of filings in the future because there is asbestos in more than half of all buildings erected in the United States during the three decades from 1940 to 1970, and in
4 1150 HOUSTON LAW REVIEW [51:4 specific theory of causation, such as the lenient any-exposure theory of causation, 15 leads plaintiffs to forum-shop to present their case favorably with the support of expert testimony that other courts would exclude. 16 Asbestos litigation has a tendency to reshape itself over time. 17 This Comment will argue that it is time for asbestos litigation to reshape itself once more. 18 Asbestos litigation should align itself with the fundamentals of general tort and toxic tort causation theories. To achieve this realignment, judges should adhere to the judicial gate-keeping roles and exclude expert testimony that departs from both traditional toxic tort and scientific principles. Part II briefly discusses what exactly asbestos is, along with the unique diseases and challenges that arise for victims injured by it. Part III explores both the tort and scientific theories embedded in toxic tort litigation, which provide a backdrop to examine just how far courts are willing to depart from these principles. Part IV discusses the special standards and tests courts developed, used, and continue to use in asbestos cases. Part V provides a starting point to reconcile general tort and evidentiary principles with the unique problems rooted in asbestos litigation. 19 II. AN ASBESTOS PRIMER In order to understand fully the causation issues 20 in asbestos litigation, it is helpful to have a background on what exactly asbestos is, the diseases it causes, and the problems that victims typically encounter when they pursue tort claims allegedly caused by asbestos. almost every factory, school and home across the land. Janis L. Kirkland, What s Current in Asbestos Regulations, 23 U. RICH. L. REV. 375, 378 (1989) (quoting Burton T. Fried, Asbestos Abatement: A Pragmatic Survey of Problems and Solutions, in ASBESTOS: REGULATION, REMOVAL, AND PROHIBITION 113, 115 (1987)) (internal quotation marks omitted). 15. See infra Part IV.D (exposing the great deviation of the any-exposure theory from scientific and legally accepted theories). 16. William L. Anderson, Lynn Levitan & Kieran Tuckley, The Any Exposure Theory Round II Court Review of Minimal Exposure Expert Testimony in Asbestos and Toxic Tort Litigation Since 2008, 22 KAN. J.L. & PUB. POL Y 1, 14 (2012). 17. CARROLL ET AL., ASBESTOS LITIGATION, supra note 5, at See infra Part V (suggesting that courts abide by traditional tort causation principles and exclude experts who testify in ways that depart from scientific principles). 19. For a discussion of the unique problems in asbestos litigation see discussion infra Parts II.B D. 20. These causation issues are explored further in further detail in Part III.B C.
5 2014] A DOSE OF REALITY 1151 A. What Is Asbestos? Asbestos, in both its commercially produced and natural form, is pervasive; no one can escape exposure. 21 Dubbed as a magic mineral by some, 22 asbestos is indestructible by fire or water. 23 Asbestos is elastic enough to be sewn as flexible cloth material but remains tougher than steel. 24 Discovery of these magical properties occurred over two thousand years ago. 25 In fact, the Romans used fire to clean tablecloths made out of asbestos. 26 Currently, asbestos s utility and ubiquity 27 appeals to manufacturers of thousands of products, including automobile brakes, pipes, insulation in roofs of buildings, and gaskets. 28 Not all asbestos is harmful. 29 Thus, it is important to distinguish the asbestos minerals that are carcinogens, or cancer causing, from the minerals that are not carcinogens. 30 Asbestos is actually a term that describes six minerals: actinolite, amosite, anthophyllite, chrysotile, crocidolite, and tremolite. 31 These six asbestos minerals can be further broken down into two types: serpentine and amphibole. 32 The body can flush serpentine asbestos minerals, like chrysotile, even when inhaled in large doses. 33 On the other hand, amphibole minerals 21. Andrew Churg, Nonneoplastic Diseases Caused by Asbestos, in PATHOLOGY OF OCCUPATIONAL LUNG DISEASE 213, 219, (Andrew Churg & Francis H.Y. Green eds., 1988); James L. Stengel, The Asbestos End-Game, 62 N.Y.U. ANN. SURV. AM. L. 223, (2006). 22. Jeb Barnes, In Defense of Asbestos Tort Litigation: Rethinking Legal Process Analysis in a World of Uncertainty, Second Bests, and Shared Policy-Making Responsibility, 34 LAW & SOC. INQUIRY 5, 12 (2009) (quoting GEOFFREY TWEEDALE, MAGIC MINERAL TO KILLER DUST: TURNER & NEWALL AND THE ASBESTOS HAZARD 120 (2000)). 23. U.S. GEOLOGICAL SURVEY, supra note 4; Barnes, supra note 22, at U.S. GEOLOGICAL SURVEY, supra note 4; Barnes, supra note 22, at David E. Lilienfeld, The Silence: The Asbestos Industry and Early Occupational Cancer Research A Case Study, 81 AM. J. PUB. HEALTH 791, 791 (1991). 26. Joseph Hooper, The Asbestos Mess, N.Y. TIMES, Nov. 25, 1990, at Stengel, supra note 21, at U.S. GEOLOGICAL SURVEY, supra note See Anderson, Levitan & Tuckley, supra note 16, at 5 7, 41 (delineating between asbestos that causes cancer and asbestos that does not injure the human body). 30. Id. at 5 9, U.S. GEOLOGICAL SURVEY, supra note 4; Lee S. Siegel, Note, As the Asbestos Crumbles: A Look at New Evidentiary Issues in Asbestos-Related Property Damage Litigations, 20 HOFSTRA L. REV. 1139, 1149 (1992). 32. U.S. GEOLOGICAL SURVEY, supra note 4; Anderson, Levitan & Tuckley, supra note 16, at U.S. GEOLOGICAL SURVEY, supra note 4; Anderson, Levitan & Tuckley, supra note 16, at 5 7. The focus of asbestos litigation is not on serpentine asbestos minerals. Anderson, Levitan & Tuckley, supra note 16, at 5 7. Luckily, ninety-nine percent of
6 1152 HOUSTON LAW REVIEW [51:4 are cancerous and contain special characteristics that penetrate lung tissue and remain [in the body] longer. 34 It is these amphibole minerals that cause asbestos s signature diseases. 35 B. The Signature Diseases Asbestos fibers can float in the air for days at a time until deeply inhaled into people s lungs. 36 If a person inhales high levels of asbestos, 37 there is an increased risk of asbestosis, lung cancer, and mesothelioma. 38 Mesothelioma and asbestosis are signature diseases, which means that people infected by them are almost exclusively people who have breathed in the harmful and cancerous asbestos fibers. 39 Mesothelioma is a fatal cancer that affects the chest, stomach, and lungs that can occur after only minor exposure to asbestos. 40 Asbestosis is the accumulation of scar tissue in the lungs. 41 Asbestosis generally requires more exposure to asbestos than mesothelioma and affects plaintiffs with heavy occupational exposure. 42 Fortunately, plaintiffs with asbestosis are not that common anymore because of the reduction of occupational exposure limits. 43 Unfortunately, plaintiffs with asbestosis have claims that still linger in the judicial system. 44 Despite the fact that asbestosis and mesothelioma are unique or nearly unique to asbestos exposure, 45 injured asbestos used today is serpentine asbestos minerals. U.S. GEOLOGICAL SURVEY, supra note Id. 35. See id. (reporting the cancer-causing properties of amphibole fibers); see also infra Part II.B (detailing the signature diseases of asbestosis and mesothelioma). 36. Asbestos Hearings, supra note 1, at Unless otherwise noted, the carcinogenic asbestos will be the sole type of asbestos analyzed in this Comment from this point further. 38. U.S. GEOLOGICAL SURVEY, supra note Sanders, Green & Powers, supra note 6, at 401 (quoting Michael D. Green, D. Mical Freedman & Leon Gordis, Reference Guide on Epidemiology, in REFERENCE MANUAL ON SCIENTIFIC EVIDENCE 333, 364, 396 (2d ed. 2000)). 40. Wehmeier v. UNR Indus., Inc., 572 N.E.2d 320, 337 (Ill. App. Ct. 1991); U.S. GEOLOGICAL SURVEY, supra note 4; Barnes, supra note 22, at Barnes, supra note 22, at Stengel, supra note 21, at 228; Wehmeier, 572 N.E.2d at 337. Epidemiological studies estimate that asbestosis requires exposure of 25 to 100 fibers per cubic centimeter per year. Andrew Churg, Neoplastic Asbestos-Induced Diseases, in PATHOLOGY OF OCCUPATIONAL LUNG DISEASE, supra note 21, at 279, 281, U.S. GEOLOGICAL SURVEY, supra note 4; Stengel, supra note 21, at Stengel, supra note 21, at Sanders, Green & Powers, supra note 6, at 401.
7 2014] A DOSE OF REALITY 1153 plaintiffs face problems proving the link between asbestos exposure and their diseases. 46 This problem has not always prevented recovery. 47 C. A Brief History of Asbestos Litigation Asbestos-related diseases experienced explosive growth in the early twentieth century due to the useful properties of asbestos. 48 Unfortunately, the asbestos producers were aware that asbestos led to serious injuries but did not immediately acknowledge [the link] (or desire to do so). 49 In fact, the physician who first discovered asbestosis noted that economics as well as production factors... must be balanced against the medical factors before a company reveals the medical problems caused by asbestos exposure to a plant full of workers. 50 Time eventually revealed the realities of asbestos s effect on human health. 51 Yet, plaintiffs did not prevail in asbestos claims until the Fifth Circuit s decision in Borel v. Fibreboard Paper Products Corp. 52 The plaintiff, Clarence Borel, worked as an industrial insulation worker for thirty-three years. 53 He sued asbestos manufacturers alleging that a failure to warn of the dangers of asbestos caused his asbestosis and mesothelioma. 54 Borel died from these diseases before the Fifth Circuit handed down a watershed ruling: asbestos manufacturers could be subject to strict liability under a failure to warn theory DAVID L. FAIGMAN ET AL., MODERN SCIENTIFIC EVIDENCE: THE LAW AND SCIENCE OF EXPERT TESTIMONY 26:5, at (2011). For a discussion of the unique issues that plaintiffs face in asbestos litigation, see infra Part II.D. 47. See infra notes and accompanying text (noting that courts previously loosened standards of proof for plaintiffs alleging asbestos-related injuries because defendants obviously injured them) FAIGMAN ET AL., supra note 46, 26:1; see supra notes and accompanying text (describing asbestos s properties that make it flexible yet indestructible). During this period, the main use of asbestos was to produce insulation in buildings. Lilienfeld, supra note 25, at See id. at (describing the scientific discovery that linked asbestos to workers diseases, which was not revealed to the workers until later). 50. Id. at 792 (internal quotation marks omitted). For a discussion of the disease of asbestosis, see supra Part II.B. 51. See U.S. GEOLOGICAL SURVEY, supra note Borel v. Fibreboard Paper Prods. Corp., 493 F.2d 1076 (5th Cir. 1973); Stengel, supra note 21, at Borel, 493 F.2d at Id. 55. Id. at , A failure to warn theory allows a plaintiff to recover against a defendant for failing to warn of the gravity of asbestos exposure, namely that it leads to asbestosis, mesothelioma and other cancers. Id. at 1105.
8 1154 HOUSTON LAW REVIEW [51:4 Despite the great utility of asbestos, it could still be unreasonably dangerous... if unaccompanied by adequate warnings. 56 The Borel ruling began an era of asbestos litigation that was a contest between sick people and culpable entities. 57 In the years after Borel, most plaintiffs who sued with asbestos injuries held jobs in industries that physically manipulated asbestos or products containing asbestos. 58 The workers inhaled large amounts of asbestos fibers on an everyday basis. 59 Causation issues might have existed in their cases, but plaintiffs were obviously sick from demonstrable and sustained exposure to the products of the entities they were suing. 60 Worst of all, the defendants in these cases clearly acted tortiously toward injured plaintiffs. 61 Asbestos litigation skyrocketed, becoming and remaining the mass tort that dwarfs all others. 62 One scholar estimates that as of 2002, plaintiffs filed more than 730,000 claims that contained allegations of asbestos-related injuries against 8,400 different defendants. 63 These lawsuits resulted in defendants paying more than $54 billion to plaintiffs. 64 The number of cases filed started to decrease in There are several reasons for this decline. First, some states passed legislation that required potential plaintiffs to file asbestos claims only after their diseases manifested themselves. 66 Therefore, a potential plaintiff could not file a claim merely because he or she experienced a fear of suffering an asbestos-related disease Id. at Stengel, supra note 21, at CARROLL ET AL., ASBESTOS LITIGATION, supra note 5, at Id. 60. Stengel, supra note 21, at Joseph Sanders, Medical Criteria Acts: State Statutory Attempts to Control the Asbestos Litigation, 37 SW. U. L. REV. 671, (2008). 62. Deborah R. Hensler & Mark A. Peterson, Understanding Mass Personal Injury Litigation: A Socio-Legal Analysis, 59 BROOK. L. REV. 961, 1004 (1993). 63. Paul D. Carrington, Asbestos Lessons: The Consequences of Asbestos Litigation, 26 REV. LITIG. 583, (2007). 64. Id. Interestingly, one researcher found that despite the massive amounts paid to plaintiffs, only 1,598 out of more than one million plaintiffs ever reached a trial verdict. CARROLL ET AL., COSTS AND COMPENSATION, supra note 5, at 56, FAIGMAN ET AL., supra note 46, 26:1, at See, e.g., FLA. STAT (2013); GA. CODE ANN (Supp. 2013); S.C. CODE ANN (Supp. 2012); TEX. CIV. PRAC. & REM. CODE ANN (West 2011). 67. See Philip Zimmerly, Comment, The Answer Is Blowing in Procedure: States Turn to Medical Criteria and Inactive Dockets to Better Facilitate Asbestos Litigation, 59 ALA. L. REV. 771, (2008) (providing a survey of state legislation that exists in
9 2014] A DOSE OF REALITY 1155 Second, district courts created inactive dockets, increased expert testimony requirements, and managed cases in a way that avoided litigation, such as engaging in alternative dispute resolution to dispose of claims. 68 These legislative and judicial roadblocks led to a decrease in filings, 69 but in an interesting way: the diseases that appeared in courts changed. 70 In the late 1990s, a surge of cases entered the system, which was almost exclusively comprised of people with nonmalignant claims or little or no current functional impairment. 71 Eventually these cases decreased, but mesothelioma cases started to increase. 72 The increase in mesothelioma filings is the most important change in this era of asbestos litigation because these are the most serious and consequently most costly injuries. 73 Therefore, how courts handle mesothelioma plaintiffs claims could be more important than ever. Further, defendants that are subject to asbestos suits also changed. Many of the traditional defendants 74 from the peak of Florida, Georgia, Texas, South Carolina, and Kansas, which imposes medical requirements for filing asbestos lawsuits); see also Sanders, supra note 61, at (providing more overview of state statutes that includes an additional state, Ohio). These state statutes require potential plaintiffs to show that they are actually physically impaired before allowing them to file a lawsuit. Patrick M. Hanlon & Anne Smetak, Asbestos Changes, 62 N.Y.U. ANN. SURV. AM. L. 525, (2007); Zimmerly, supra, at 780. A benefit for potential defendants is that it is harder for plaintiffs lawyers to find potential plaintiffs that have weak or nonexistent evidence [of injury] that will sit on the docket accumulating settlement value. Id. at See Jeb Barnes, Rethinking the Landscape of Tort Reform: Legislative Inertia and Court-Based Tort Reform in the Case of Asbestos, 28 JUST. SYS. J. 157, (2007) (providing a summary all of these court reforms in asbestos litigation) FAIGMAN ET AL., supra note 46, 26:1, at Hanlon & Smetak, supra note 67, at CARROLL ET AL., ASBESTOS LITIGATION, supra note 5, at 73. One scholar points out the irony that the increase in claims was attributable, in part, to the consolidation of cases. Sanders, supra note 61, at 672. Consolidation of cases was done because the amount of asbestos cases was seemingly impossible to work through. Id. [T]he increased efficiency of consolidated proceedings encouraged additional filings, which probably contained weak cases. Id. 72. CARROLL ET AL., ASBESTOS LITIGATION, supra note 5, at Id.; CARROLL ET AL., COSTS AND COMPENSATION, supra note 5, at 44. Indeed, although they remain a small portion of the overall total filings, mesothelioma claims receive twenty-eight to thirty percent of the overall compensation paid to asbestos victims. Hanlon & Smetak, supra note 67, at Traditional defendants in asbestos litigation come from the following industries: shipyards, construction, chemicals, utilities, railroad and automobile maintenance, and asbestos miners, manufacturers, and installers. CARROLL ET AL., ASBESTOS LITIGATION, supra note 5, at
10 1156 HOUSTON LAW REVIEW [51:4 asbestos litigation declared bankruptcy. 75 A fear arose that solvent defendants would run out of money. 76 Plaintiffs then began to seek relief from nontraditional defendants with more attenuated liability. 77 This development in turn caused, and continues to cause, defendants with little available money to defend cases by plaintiffs with little or no impairment. 78 This combination of changes paints a legally interesting picture: defendants with little money and attenuated liability encountering a mix of plaintiffs who have little or no impairment and plaintiffs suffering from a debilitating cancer that is uniquely attributed to asbestos. Unfortunately, both types of plaintiffs, impaired and unimpaired, suffer from the inability to prove their cases because of unique problems caused by asbestos. D. The Signature Problems Plaintiffs that pursue asbestos litigation encounter two issues in suing for their asbestos-related injuries. First, there is a relatively long period between a plaintiff s exposure to asbestos and manifestation of his or her asbestos-related disease. 79 This period is called a latency period. 80 Mesothelioma, for example, typically does not manifest itself until thirty to forty years after a person s exposure to asbestos. 81 Therefore, plaintiffs with the most serious asbestos-related diseases are unable to determine which manufacturer created the products that exposed them to asbestos. 82 Often, in an attempt to overcome the latency between exposure and disease, plaintiffs will sue all manufacturers that produced the products that might have exposed the plaintiff to asbestos. 83 However, this sometimes leads to defendants FAIGMAN ET AL., supra note 46, 26:1, at 548; Sanders, supra note 61, at Sanders, supra note 61, at FAIGMAN ET AL., supra note 46, 26:1, at ; Sanders, supra note 61, at 673. This growing trend of suing nontraditional defendants is discussed further in infra notes and accompanying text. 78. Sanders, supra note 61, at Sanders, Green & Powers, supra note 6, at FAIGMAN ET AL., supra note 46, 26:20, at Sporn & Roggli, supra note 14, at Sanders, Green & Powers, supra note 6, at Id. at 403; see, e.g., Lohrmann v. Pittsburgh Corning Corp., 782 F.2d 1156, 1162 (4th Cir. 1986) ( [M]ost plaintiffs sue every known manufacturer of asbestos products, and during the course of discovery some of the defendants are dismissed on motions for
11 2014] A DOSE OF REALITY 1157 dismissals by either summary judgment or a directed verdict because the plaintiff s exposure to their product is too tenuous. 84 Second, even when plaintiffs might be fortunate enough to know the defendant who produced the asbestos that caused their disease, it is very hard to prove with any precision the amount of exposure to the product. 85 This second problem calls attention to the single most important factor to consider in evaluating whether an alleged exposure caused a specific adverse effect, which is dose. 86 The importance of dose is widely recognized as the foundation of causation in toxic tort cases. 87 III. LEGAL AND SCIENTIFIC PRINCIPLES OF TOXIC TORT CASES In order to appreciate just how far courts depart from traditional toxicology, tort, and toxic tort principles in deciding asbestos litigation, 88 it is helpful to understand their basic underpinnings. A. A Quick Toxicology Primer Virtually all substances have the ability to be toxic. 89 Whether a substance is harmful or not depends on the dose received. 90 Dose is the amount of a particular chemical that enters the body. 91 However, chemicals only lead to diseases in the human body when the dose is sufficiently high. 92 If the dose is high enough, the body will reach a point where its defenses summary judgment because there has been no evidence of any contact with any of such defendants asbestos-containing products. ). 84. Sanders, Green & Powers, supra note 6, at Id. at See David L. Eaton, Scientific Judgment and Toxic Torts A Primer in Toxicology for Judges and Lawyers, 12 J.L. & POL Y 5, (2003) (clarifying the concepts of dose and exposure and the relationship between the two). 87. See, e.g., McClain v. Metabolife Int l, Inc., 401 F.3d 1233, 1241 (11th Cir. 2005) ( In toxic tort cases, [s]cientific knowledge of the harmful level of exposure to a chemical plus knowledge that plaintiff was exposed to such quantities are minimal facts necessary to sustain the plaintiff s burden.... (alteration in original) (quoting Allen v. Pa. Eng g Corp., 102 F.3d 194, 199 (5th Cir. 1996))). The relationship between dose and toxicology in proving causation is discussed infra Part III.A. 88. See infra Part IV (providing an overview of the standards courts developed to address causation issues in asbestos litigation). 89. Eaton, supra note 86, at See Anderson, Levitan & Tuckley, supra note 16, at 7 (describing the threshold point where the body can no longer resist a substance s harmful properties). 91. Eaton, supra note 86, at Anderson, Levitan & Tuckley, supra note 16, at 7.
12 1158 HOUSTON LAW REVIEW [51:4 will no longer function to protect itself, which is referred to as the threshold point. 93 In order to prove causation in an asbestos case, the plaintiff must establish that his or her exposure to asbestos is of sufficient magnitude to exceed the threshold [point]. 94 A general principle of toxicology is the dose-response relationship. 95 The dose-response in a given individual describes the relationship between the magnitude or severity of the effect(s) and the dose. 96 If there is a high dose-response relationship, further increases in the dose may produce large increases in the response. 97 To make this scientific concept more easily understandable, Dr. David L. Eaton uses the familiar example of alcohol. 98 If a person drinks a few glasses of wine, then there is a stimulatory effect otherwise known as intoxication. 99 However, if one continues to drink more and more alcohol, one may be rendered unconscious or die. 100 Application of these notions to asbestos litigation reveals that both asbestosis and mesothelioma are thought to have a minimum threshold dose that the body can absorb. 101 However, beyond the threshold point for asbestosis, the severity of the disease increases proportionally to the dose past the threshold point; i.e., the disease follows the dose-response relationship. 102 To determine a defendant s liability, it is important to know how each disease manifests. If a defendant contributes to a plaintiff s asbestosis or mesothelioma threshold dose, that defendant would be liable for the onset of the disease as well as its aggravation once the threshold was crossed. 103 However, a defendant who exposed a person to asbestos after they had 93. Id. (internal quotation marks omitted). 94. Eaton, supra note 86, at Id. 96. Id. at Id. 98. Id. 99. Id. (internal quotation marks omitted) Id See Behrens & Anderson, supra note 9, at 490. Numerous theories convey that there is no safe level of asbestos exposure, which provides great fodder and is easy for an expert to sell to a jury. See id. at The threshold dose for mesothelioma is thought to be quite low. Sanders, Green & Powers, supra note 6, at 424. Further, once mesothelioma manifests itself, additional exposure does not affect the severity of the disease. Id. at FAIGMAN ET AL., supra note 46, 26:24, at 621; Sanders, Green & Powers, supra note 6, at Sanders, Green & Powers, supra note 6, at 422.
13 2014] A DOSE OF REALITY 1159 reached the threshold point of asbestosis would contribute to aggravation of the disease, as determined by the dose-response relationship. 104 In other words, the defendant did not contribute to the onset of the disease but contributed to the severity of the disease. 105 Unfortunately, determining a defendant s liability is not as simple as it first appears. B. A Quick Tort Causation Primer In an asbestos tort case, a plaintiff must prove the defendant s product was either a cause in fact, or a but-for cause, to the plaintiff s disease. 106 Conduct is a but-for cause when the harm would not have occurred absent the [defendant s] conduct. 107 The Second Restatement of Torts provides an alternative way of determining but-for causation called the substantial factor test. 108 Both courts and experts use the substantial factor test in many different ways when explaining causation issues in asbestos litigation. 109 The substantial factor test is an alternative causal test that imposes liability when multiple causes would render a defendant not liable under typical but-for causation. 110 It states when two forces are actively operating, one because of 104. Id Id Behrens & Anderson, supra note 9, at 483. The terms but-for cause and factual cause are interchangeable. RESTATEMENT (THIRD) OF TORTS: LIABILITY FOR PHYSICAL AND EMOTIONAL HARM 26 cmt. b (2010). For the sake of simplicity and cohesiveness, the term but-for causation will be used to describe factual cause, cause-infact, and any other terms to indicate this type of causation Id. 26. The Second Restatement of Torts did not separate legal causation into proximate cause and but-for cause. Ken Oliphant, Uncertain Factual Causation in the Third Restatement: Some Comparative Notes, 37 WM. MITCHELL L. REV. 1599, 1601 (2011). Thus, some courts and scholars are really referring to but-for causation when they say proximate cause, but referring to the concept in the more general Second Restatement sense of legal causation. See id. (noting the First and Second Restatement of Torts used only one concept for causation, which is referred to as legal cause ). The Third Restatement, however, actually subdivides causation into two separate types: factual cause and proximate cause. Id. The substantial factor test clearly is another way to determine but-for cause. Id RESTATEMENT (SECOND) OF TORTS 432 (1965); see also Sanders, Green & Powers, supra note 6, at In actuality, the substantial factor test was designed as a limit on proximate cause, not but-for cause. RESTATEMENT (SECOND) OF TORTS 42, at (1965); W. PAGE KEETON ET AL., PROSSER AND KEETON ON THE LAW OF TORTS 41 42, at 267 (5th ed. 1984) Sanders, Green & Powers, supra note 6, at For further discussion of the variations of substantial factor, see discussion infra Part IV (discussing various tests developed by courts around the country) Sanders, Green & Powers, supra note 6, at
14 1160 HOUSTON LAW REVIEW [51:4 the actor s negligence, the other not because of any misconduct on his part, and each of itself is sufficient to bring about harm to another, then the actor s negligence is a substantial factor in producing harm and therefore is a but-for cause. 111 Two specific situations called for the development of the substantial factor test. 112 The first situation is called the two-fire problem. 113 In Kingston v. Chicago & Northwest Railway Co., two independent fires converged and destroyed the plaintiff s property. 114 Sparks from the defendant s locomotive caused one fire; the cause of the other fire remained unknown. 115 The issue arose that even if one of the fires had not existed, the other fire would still have destroyed the property. 116 The defendant argued that it should escape liability because the fire could have occurred without the defendant s locomotive sparking a fire. 117 The court rejected the defendant s argument and held the defendant liable, noting that [n]o principle of justice requires that the plaintiff be placed under the burden of specifically identifying the origin of both fires in order to recover the damages for which either or both fires are responsible. 118 Courts and experts sometimes misidentify and label scenarios in asbestos litigation as Kingston two-fire problems when they are not. 119 A proper application of the substantial factor test is as follows: assume a person can resist a dose of 1,000 units of asbestos. 120 If he or she is exposed to more than 1,000 units of asbestos, then he or she will develop asbestosis RESTATEMENT (SECOND) OF TORTS 432 (1965). This concept is called multiple sufficient causes in the Third Restatement. RESTATEMENT (THIRD) OF TORTS: LIABILITY FOR PHYSICAL AND EMOTIONAL HARM 27 (2010) Sanders, Green & Powers, supra note 6, at Id Kingston v. Chi. & N.W. Ry. Co., 211 N.W. 913, 914 (Wis. 1927) Id Id. at Id. A more colorful example is provided by Prosser and Keeton. KEETON ET AL., supra note 108, 41, at 271. If two shooters negligently fire rifles, and one bullet pierces a victim s heart, either shooter could claim that the victim would have died anyway without the aid of their bullet. Id. In other words, each shooter could claim their bullet was not a but-for cause. Id. This argument would wrongly relieve the shooters from liability. Id Kingston, 211 N.W. at Sanders, Green & Powers, supra note 6, at 417 & n.79; see, e.g., Knodle v. Waikiki Gateway Hotel, Inc., 742 P.2d 377, (Haw. 1987); see also infra Parts IV.D, V.A This example is taken from Sanders, Green & Powers, supra note 6, at For discussion of what exactly occurs when a person suffers from asbestosis, see supra notes and accompanying text. For a discussion of dose and threshold point, see supra Part III.A.
15 2014] A DOSE OF REALITY 1161 If twelve defendants each expose the person to 100 units of asbestos, the dose of 1,200 units will cross the threshold point of 1,000 units and lead to asbestosis. 122 Each defendant might take the stance of the defendant in Kingston and argue that the disease would have occurred in the absence of their exposure. However, the substantial factor test could hold each defendant liable because multiple forces (i.e., asbestos exposures) were actively operating and each was sufficient to bring about harm to the person exposed to asbestos from each defendant. 123 In a similar, but improper, use of the substantial factor test, assume that the same person that can resist 1,000 units of asbestos without developing asbestosis. 124 He or she is then exposed to 600 units of asbestos from two defendants at the same time for a total of 1,200 units of asbestos. 125 If each defendant exposed the plaintiff to 600 units, there is no need to resort to substantial factor causation; each defendant was the but-for cause of the plaintiff s asbestosis. 126 The harm (i.e., the asbestosis) would not have occurred but for the defendant s conduct. Here, one can determine that it was exactly two defendants that were the but-for causes: in the absence of one defendant s conduct, the plaintiff would not have been exposed to the required dose to develop asbestos. In the proper application of the two-fire problem discussed previously, 127 even if one hypothetically removes a defendant from the scenario, the but-for cause is not apparent. 128 The plaintiff still would have the requisite amount for the development of asbestosis. The second situation the substantial factor test is designed to address is trivial but-for causes. 129 The substantial factor test 122. For a discussion of threshold point, see supra notes and accompanying text See RESTATEMENT (SECOND) OF TORTS 432 (1965); RESTATEMENT (THIRD) OF TORTS: LIABILITY OF PHYSICAL AND EMOTIONAL HARM 27 (2010) Sanders, Green & Powers, supra note 6, at Id See RESTATEMENT (SECOND) OF TORTS 432 (1965); RESTATEMENT (THIRD) OF TORTS: LIABILITY OF PHYSICAL AND EMOTIONAL HARM 27 (2010) (describing factual cause to a plaintiff s injury as established when the harm would not have occurred in the absence, or but for, the defendant s conduct); Sanders, Green & Powers, supra note 6, at See supra notes (discussing the two-fire problem presented by the Kingston case) The but-for cause is not apparent because if one removes a defendant who contributed 100 units of asbestos, then the plaintiff still exceeds the threshold dose of 1,000 units. See supra notes and accompanying text Sanders, Green & Powers, supra note 6, at 418.
16 1162 HOUSTON LAW REVIEW [51:4 is thus appropriate when it is clear that the defendant s actions were a but-for cause that was nevertheless insubstantial. 130 The Second Restatement of Torts specifically notes that if events or multiple acts are but-for causes but the acts or conducts have an effect that is so insignificant that no ordinary mind would think of them as causes, then they are not a substantial factor. 131 In other words, if something is a but-for cause but is also trivial, then it should be ignored. 132 The misuse of the substantial factor test is at the heart of expert testimony issues in asbestos cases. 133 C. Additional Causation Principles in Toxic Tort Litigation In a typical toxic tort case, a plaintiff must also prove general and specific causation. 134 These two types of causation are elements within the but-for prong of causation. 135 The plaintiff is attempting to prove but for the exposure to the defendant s toxic substance, the plaintiff would not suffer his or her injury. 136 A plaintiff proves general causation when he or she shows the defendant s substance is capable of causing a particular injury or condition in the general population. 137 General causation is typically not at issue in asbestos cases; defendants usually concede it. 138 Specific causation is generally the center of attention in toxic tort cases. 139 Specific causation is met when the plaintiff proves that the toxic substance caused the injury of the plaintiff himself. 140 Specific causation requires two elements. First, the plaintiff must prove that his or her exposure to the amount of 130. Id. at RESTATEMENT (SECOND) OF TORTS 431 cmt. a (1965) Id For a discussion of the substantial factor causation issues to which experts unreliably attest, see discussion infra Parts IV.D, V.A Joseph Sanders, From Science to Evidence: The Testimony on Causation in the Bendectin Cases, 46 STAN. L. REV. 1, 14 (1993). General and specific causation are fleshed out in infra notes and accompanying text David E. Bernstein, Getting to Causation in Toxic Tort Cases, 74 BROOK. L. REV. 51, (2008) See KEETON ET AL., supra note 108, 41, at Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706, 714 (Tex. 1997) FAIGMAN ET AL., supra note 46, 26:3, at 529. When the plaintiff alleges an injury that is not typically associated with asbestos, like colon, esophageal, and laryngeal cancers, then the defendant is more likely to attack general causation. Id. Also, if the plaintiff is alleging their injury occurred as a result of an asbestos fiber that is not considered to have the ability to cause the plaintiff s injury, then general causation might be at issue. Id. 26:3, at Bernstein, supra note 135, at Merrell Dow, 953 S.W.2d at 714.
17 2014] A DOSE OF REALITY 1163 toxin has the ability to cause his or her specific illness. 141 Second, because a plaintiff must prove specific causation by a preponderance of the evidence, 142 courts require the plaintiff to show that the exposure to the defendant s product doubled the risk of the plaintiff s disease. 143 Courts often refer to the doubling of the risk as a relative risk of greater than two. 144 Courts rely on epidemiological testing to prove these two subelements of specific causation. 145 Epidemiology is an area of study concerned with linking exposure to substances with injuries. 146 Although epidemiological studies are not an exact science, 147 they are the gold standard for establishing causation. 148 There are other forms of evidence to prove causation, such as structural similarity, in vitro testing, and case reports, but epidemiology is at the top. 149 Regardless of the type of evidence the plaintiff uses to prove specific causation, he or she must use the evidence in a way that a reasonable person could conclude that a defendant s emission has probably caused a particular plaintiff the kind of harm of which he or she complains. 150 In toxic tort cases, plaintiffs establish specific causation by relying on various types of scientific evidence to gather data to calculate relative risk. 151 For example, in Merrell Dow 141. Bernstein, supra note 135, at Sanders, supra note 134, at Bernstein, supra note 135, at Id. To put this in more relatable terms, a relative risk of 1.0 indicates there is no difference in the occurrence of a disease between someone exposed to a toxin, like asbestos, and someone not exposed to asbestos, while a relative risk greater than 1.0 indicates stronger evidence of general causation. See id. A preponderance of the evidence is also the level of proof for general causation. Id Id. at FAIGMAN ET AL., supra note 46, 23:1, at Bernstein, supra note 135, at Behrens & Anderson, supra note 9, at 490 (internal quotation marks omitted). Scholars note that epidemiology can be a two edged sword. 3 FAIGMAN ET AL., supra note 46, 23:1, at 215. While epidemiological evidence may show correlation between a substance and an injury, like tobacco s effects on health, the lack of epidemiological evidence tying an exposure to an injury sometimes acts as a barrier to recovery. Id Michael D. Green, Expert Witnesses and Sufficiency of Evidence in Toxic Substances Litigation: The Legacy of Agent Orange and Bendectin Litigation, 86 NW. U. L. REV. 643, 658 (1992) Parker v. Mobil Oil Corp., 857 N.E.2d 1114, 1121 (N.Y. 2006) (quoting Wright v. Willamette Indus., Inc., 91 F.3d 1105, 1107 (8th Cir. 1996)). Courts have held that in order to show the probability that the defendant caused the harm, the plaintiff must show a relative risk greater than 2.0. See supra note 144 and accompanying text (describing what relative risk is and how it is determined) Merrell Dow Pharm., Inc. v. Havner, 953 S.W.2d 706, 716 (Tex. 1997). For the definition of relative risk and how it functions in toxic tort cases, see supra notes and accompanying text.
18 1164 HOUSTON LAW REVIEW [51:4 Pharmaceuticals, Inc. v. Havner, the court addressed the question of whether Bendectin, a prescription drug for alleviating symptoms of morning sickness during pregnancy, caused a birth defect. 152 Multiple experts testified that Bendectin could cause the same birth defect from which the plaintiff suffered. 153 In fact, an expert whose credentials were described as impressive by the U.S. Supreme Court testified to a reasonable degree of medical certainty that the drug caused the plaintiff s birth defect. 154 Ultimately, the court ruled against the plaintiff because the studies provided by her experts did not identify a relative risk greater than two. 155 Because the studies did not have a sufficient relative risk, the plaintiff could not meet her burden to prove by a preponderance of the evidence that Bendectin caused her birth defect. 156 IV. HOW AND WHY DO ASBESTOS CASES DEPART FROM GENERAL TORT PRINCIPLES? Asbestos litigation has distinct causation rules that are different from typical tort litigation. 157 Perhaps this is because if the courts employed the typical but-for test for proving causation, plaintiffs would have a hard time proving that a defendant s product caused their injury. 158 These rules, their 152. Merrell Dow, 953 S.W.2d at This is an example of proving general causation. See supra notes and accompanying text (providing a definition of general causation); see also Merrell Dow, 953 S.W.2d at (noting that in most Bendectin litigation, there have been questions about the scientific reliability of expert testimony as to causation) Merrell Dow, 953 S.W.2d at 711 (quoting Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 583 & n.2 (1993)). This is an example of specific causation. See supra notes and accompanying text (describing specific causation and its application in toxic tort litigation) Merrell Dow, 953 S.W.2d at 730. The studies identified by the court had relative risk ranges between 0.7 and 1.8. Id. at Id. at 730. See supra notes and accompanying text (describing how courts require relative risk to prove causation in toxic tort litigation) Anderson, Levitan & Tuckley, supra note 16, at See 3 FAIGMAN ET AL., supra note 46, 26:5, at One author summarizes the problems that led to the different treatment of causation in asbestos litigation as attributable to [t]he many types of asbestos products, the many possible places of exposure, the lack of direct evidence of particular product exposure, and the possibility of contributing factors. Brian M. DiMasi, Comment, The Threshold Level of Proof of Asbestos Causation: The Frequency, Regularity and Proximity Test and a Modified Summers v. Tice Theory of Burden-Shifting, 24 CAP. U. L. REV. 735, (1995); see also Sanders, Green & Powers, supra note 6, at (discussing the daunting task of proving causation in asbestos cases ); supra Part II.D (elaborating on the two signature problems of asbestos litigation).
19 2014] A DOSE OF REALITY 1165 development, and their increasing departure from traditional tort and toxic tort principles are discussed in turn below. A. Lohrmann: The Most Widely Used Causation Test in Asbestos Litigation The Lohrmann test is the most common test used for causation in asbestos cases. 159 In Lohrmann, the plaintiff worked as a pipefitter at Bethlehem Steel in Baltimore. 160 He suffered from asbestosis and sued nineteen defendants, alleging negligence and failure to warn theories. 161 He could only prove exposure to one asbestos-containing product: a pipe manufactured by Pittsburgh Corning, which contained an asbestos product, Unibestos. 162 In the course of his thirty-nineyear employment with Bethlehem Steel, he encountered Unibestos ten to fifteen times for periods of one to eight hours. 163 In the Lohrmann case, the court had to deal with two distinct issues. The first issue was whether the plaintiff suffered exposure from the defendant s product. 164 The second issue was if the plaintiff established that he suffered asbestos exposure from the defendant s product, whether the exposure was sufficient to support a finding of [substantial factor] causation. 165 The court concluded as a matter of law that the exposure to Unibestos was not a substantial factor in the development of the plaintiff s asbestosis by creating a test: the frequency, regularity, and proximity test, or the Lohrmann test. 166 The court designed the frequency, regularity, and proximity test to meet the problem of the long latency period associated with asbestos-related diseases. 167 To meet the 159. Bernstein, supra note 135, at Lohrmann v. Pittsburgh Corning Corp., 782 F.2d 1156, 1158 (4th Cir. 1986) Id. Mr. Lohrmann s failure to warn theory is the same theory that the first successful plaintiff in asbestos litigation, Mr. Borel, pursued. See supra notes and accompanying text (explaining the failure to warn theory in the context of asbestos litigation) Lohrmann, 782 F.2d at Id Sanders, Green & Powers, supra note 6, at Id Lohrmann, 782 F.2d at 1163; Sanders, Green & Powers, supra note 6, at ; see also supra Part III.B (providing an overview of substantial factor causation) Bernstein, supra note 135, at Some plaintiffs diseases do not manifest themselves until thirty to forty years after their exposure. 3 FAIGMAN ET AL., supra note 46, 26:24, at 588; Sanders, Green & Powers, supra note 6, at See supra notes and accompanying text for more discussion of latency periods in asbestos litigation.
20 1166 HOUSTON LAW REVIEW [51:4 Lohrmann test, a plaintiff must prove: (1) exposure to a defendant s product, (2) regular exposure over time, (3) proximity to where the plaintiff s exposure occurred, and (4) probability that the defendant s product injured the plaintiff. 168 The court expressly rejected the plaintiff s argument that if the plaintiff can present any evidence that a company s asbestoscontaining product was at the workplace while the plaintiff was at the workplace, a jury question has been established as to whether that product contributed as a proximate cause to the plaintiff s disease. 169 Years later, courts would allow experts to testify to just the opposite. 170 B. Flores: The First Court of Last Resort Addresses the Lack of Dosage in Asbestos Litigation The Texas Supreme Court became the first state court of last appeal to reject the any exposure theory of causation in the case of Borg-Warner Corp. v. Flores. 171 The plaintiff, Arturo Flores, worked as a brake mechanic for thirty-five years at Sears. 172 Throughout his years as a brake mechanic, he changed many different brands of brake pads, including pads that Borg-Warner manufactured. 173 He used Borg-Warner s pads over the course of three years on about 25% of his brake jobs. 174 Mr. Flores put forth an expert that testified that he had asbestosis due to his exposure to asbestos from the brake pads. 175 At the trial court level, the jury apportioned 37% of causation of Mr. Flores s asbestosis to Borg-Warner. 176 The Texas Supreme Court reversed and rendered judgment for Borg-Warner, the defendant. 177 Although it appeared that 168. Lohrmann, 782 F.2d at Id. at See infra Part IV.D (discussing the any-exposure theory, which purports that any exposure, no matter how small, is a substantial factor in contributing to a plaintiff s asbestosis, mesothelioma, or other asbestos-related disease) Behrens & Anderson, supra note 9, at Borg-Warner Corp. v. Flores, 232 S.W.3d 765, 766 (Tex. 2007) Id Id Id Id. at 768. There were three other defendants in this case. Id. Each one of those defendants was apportioned twenty-one percent of liability for a total of one hundred percent liability attributed to the four defendants. Id. Mr. Flores also suffered an additional lung injury that, according to his expert, was unrelated to asbestos exposure. Id. at 767. In addition, Mr. Flores smoked fifty packs a year; however, this information was never used to challenge the reliability of Mr. Flores s experts. Id. at 768, 769 n Id. at 766.