Some legal scholars have suggested that apportionment of damages by causation is a 20th century reform to the common law[1]. This strikes view strikes me as ignoring the late 20th century American courts’ penchant for favoring joint and several liability, without apportionment, and its hostility or refusal to permit causal apportionments. See, e.g., Carter v. The Wallace & Gale Asbestos Settlement Trust, 439 Md. 333, 96 A.3d 147 (2014). See also “Maryland Refuses Apportionment in Asbestos Lung Cancer Cases – Carter” (Sept. 19, 2014); “Further Thoughts on the Carter Apportionment Case – The Pennsylvania Experience” (Sept. 20, 2014).
The common law, as it developed in the United States from the early 19th century, was hospitable to apportionments that avoided “entire” or “joint and several” liability. Apportionments of single harms were often permitted and encouraged by the use of reasonable estimates of relative causal contributions. The common law generally provided that entire liability, and its procedural consequences similar to joint and several liability, did not apply to concurrent or successive tortfeasors whose acts (or products) cause distinct injuries or cause an injury that can be reasonably apportioned.
Asbestos (and other similar) cases raise interesting questions about the divisibility and apportionment of physical injuries and resulting impairment or death. Asbestosis represented the cumulative fibrotic result from multiple exposures to asbestos, over the course of an entire occupational exposure. For workers who were exposed to asbestos that came from different manufacturers’ products, the workers’ asbestosis represents the cumulative, single result of all the exposures that resulted in pulmonary deposition of fibers. A very slight, passing exposure may not have contributed at all to pulmonary deposition and retention. Heavier, more sustained exposures might contribute to the overall fiber burden, but certainly not equally. Exposures, deposition, and retention would be expected to vary in proportion to the use and dustiness (asbestos) of each product, weighted by the duration of exposure from each product. If all products were used equally, and were equally dusty, then perhaps they all could be taken to contribute equally. This last hypothetical, however, ignores the reality of market dominance of a few manufacturers, such as Johns-Manville up through the end of asbestos use in insulation.
The situation with mesothelioma is more complicated because not all commercial asbestos fiber types have the same potency with respect to causing mesothelioma. Crocidolite fiber has a potency an order of magnitude greater than amosite fiber. Chrysotile, even with some tremolite contamination, is orders of magnitude below crocidolite in its ability to cause mesothelioma, if it does so at all. These complexities of varying potency can be modeled by dustiness, duration of exposure, intensity of exposure, and potency factors. A further consideration is that mesothelioma arises from one or a few cells deranged by an asbestos fiber in close proximity. Increasing exposure would appear to increase the risk of malignant change, but the change is likely a local phenomenon, not the result of total fiber burden. (Increasing total fiber burden, however, represents an increasing risk of mesothelioma induction.) The assessment of causal responsibility is essential an attribution based upon ex ante risk, not actual causation. Given this reality, there is no reason that the causation cannot and should not be apportioned by the magnitude of the risk, modeled as suggested above.
The scholar’s suggestion that apportionment is a new-fangled development in tort law, and a reform of the common law, does not appear to hold up on close scrutiny. The common law dealt with combined causes in a variety of situations, and liberally permitted apportionment even for single harms, when there was a rational basis. As Restatement (Second) of Torts makes clear, even so-called distinct harms may require some “rough” estimation in attributing damages to the tortfeasors responsible for the different harms. Restatement (Second) of Torts § 433A (1965). Comment b to this section rather circularly defines “distinct harms” as those “results which, by their nature, are more capable of apportionment.” The comment states a hypothetical case and suggested resolution, which are, however, more helpful:
“If two defendants independently shoot the plaintiff at the same time, and one wounds him in the arm and the other in the leg, the ultimate result may be a badly damaged plaintiff in the hospital, but it is still possible, as a logical, reasonable, and practical matter, to regard the two wounds as separate injuries, and as distinct wrongs. The mere coincidence in time does not make the two wounds a single harm, or the conduct of the two defendants one tort. There may be difficulty in the apportionment of some elements of damages, such as the pain and suffering resulting from the two wounds, or the medical expenses, but this does not mean that one defendant must be liable for the distinct harm inflicted by the other. It is possible to make a rough estimate which will fairly apportion such subsidiary elements of damages.”
The above hypothetical is very much analogous to cases that occur in asbestos personal injury and property damage litigation. The Restatement also provides for apportionment of damages in cases in which the plaintiff suffers a single but divisible harm. Restatement § 433A(1)(b). Apportionment is permitted for such a harm when “there is a reasonable basis for determining the contribution of each cause.” Id. at comment d, the Restatement gives several examples of joint torts that can be apportioned by cause. Of particular interest is the suggestion that:
“Apportionment is commonly made in cases of private nuisance, where the pollution of a stream, or flooding, or smoke or dust or noise, from different sources, has interfered with the plaintiff’s use or enjoyment of his land. Thus where two or more factories independently pollute a stream, the plaintiff’s use of the water may be treated as divisible in terms of degree, and may be apportioned among the owners of the factories, on the basis of the respective quantities of pollution discharged into the stream.”
Id. See also 1 S. Speiser, C. Krause & A. Gans, The American Law of Torts at § 3.12 & note 88 (1983 & Supp. 1984) (collecting cases on joint flooding and polluting). Like a stream wasted by pollution, a person’s lungs impaired by fibrosis should be divisible “in terms of degrees” of contribution to the outcome.
Some of the earliest cases giving rise to an apportionment of property damages have involved the worrying and killing of sheep by dogs belonging to two or more persons. Many of these early cases involved the propriety of joinder of the dog owners and the resultant joint liability. Under the common-law approach to joinder, courts found it “repugnant to the plainest principles of justice to say that the dogs of different persons, by joining in doing mischief could make the owners jointly liable.” Russell v. Tomlinson & Hawkins, 2 Conn. 206 (1817). Consequently, if two dogs, each belonging to different persons, run together and kill the plaintiff’s sheep, each owner is liable only for the sheep his dog killed. Id. (“no man can be liable for the mischief done by the dog of another, unless he had some agency in causing the dog to do it.”) Van Steenburgh v. Tobias, 17 Wend. 562 (N.Y. 1837) (affirming nonsuit based upon misjoinder because joinder was error unless defendants jointly liable). The court in Van Steenburgh noted that the imposition of joint liability on the owner of one dog, which happened to unite with other dogs in destroying a herd, would be unjust. Id. at 564. The difficulty in estimating the separate injury done by each dog does not permit imposing liability for the entire damage. Id. at 563.
In Adams v. Hall, 2 Vt. 9 (1829), the court rejected the plaintiff’s argument that the damage done to his property, a herd of sheep, was entire. Id. at 10, 11. Because the damage done by each defendant’s dog was separate, the defendants were misjoinded under the then current procedural rules. Id. at 11.
In Buddington v. Shearer, 37 Mass. (20 Pick.) 477 (1838), the court acknowledged that the plaintiff would have some difficulty in proving which dog caused what distinct harm, but that under the circumstances, the trier of fact could reasonably apportion damages equally on the assumption that the dogs were capable of equal mischief. Id. at 479-80.
In the absence of a statute, the rule requiring apportionment in dog and sheep cases remains valid. See Miller v. Prough, 203 Mo. App. 413, 425, 221 S.W. 159 (1920) (each owner of a dog may not be liable for the entire damage; evidence of relative size and ferocity sufficient to permit the jury to apportion damages); Stine v. McShane, 55 N.D. 745, 746 214 N.W. 906 (1927) (in absence of a joint tort or a statute modifying the common law, plaintiff can recover only those damages occasioned by that defendant’s conduct); Nohre v. Wright, 98 Minn. 477, 478-79, 108 N.W. 865 (1906) (each dog owner is liable separately for the damages done by his animal); Anderson v. Halverson, 126 Iowa 125, 127, 101 N.W. 781 (1904) (reversing judgment for defendant dog owner because although plaintiff could not show which defendant’s dog killed which sheep, the jury should have been allowed to consider defendant’s liability with proper instructions on apportionment), Denny v. Correll, 9 Ind. 72, 73 (1857) (per curiam) (reversing joint judgment against defendant dog owners); Dyer v. Hutchins, 87 Tenn. 198, 199, 10 S.W. 194 (1889)(each defendant dog owner is responsible only for the depradations of his own animal).
The validity of the apportionments made for separate harms in dog and sheep cases continued into the second half of the 20th century, as evidenced by the following illustration in the Second Restatement:
“Five dogs owned by A and B enter C’s farm and kill ten of C’s sheep. There is evidence that three of the dogs are owned by A and two by B, and that all of the dogs are of the same general size and ferocity.”
Second Restatement § 433A, illustration 3. Based upon these facts, the Second Restatement would hold A liable for the value of six of the sheep, and B liable for four. Id.
The destruction of a field or its crops presents a case of harm, which courts have often treated as single but divisible. In Powers v. Kindt, 13 Kan. 74 (1874), the plaintiff sued for the damage inflicted to his crops by cattle belonging to two unrelated parties. Noting that the plaintiff had suffered a single injury to his property, the court held that the damages for the single injury should be apportioned by the relative number of each defendant’s cattle. Id. at 83. In Wood v. Snider, 187 N.Y. 28, 79 N.E. 858 (1907), the plaintiff sued an owner of cattle, which had trespassed along with the cattle belonging to other persons, on the plaintiff’s land. Id. at 36, 79 N.E. 858. The court noted that the cattle were all on the plaintiff’s land and that they all caused equal damage to the plaintiff, and, therefore, each cattle owner was liable for his proportionate share of the entire damages. Id. Accord Pacific Live Stock Co. v. Murray, 45 Or. 103, 76 P. 1079 (1904) (the proper measure of plaintiff’s damages was the value of pasturage consumed by defendant’s sheep, not the mischief done by animals belonging to other persons); Hill v. Chappel Brothers of Montana, 93 Mont. 92, 103, 18 P. 2d 1106 (1933) (jury allowed to make the best possible estimate of the portion of damages attributable to the defendant’s horses).
Other courts, in considering animal trespass cases, have not emphasized whether they viewed the plaintiff’s injury as single or several. Rather, these courts, simply have stressed the reasonable divisibility of damages and the appropriateness of apportioning damages accordingly. Westgate v. Carr, 43 Ill. 450, 454-44 (1867) (each defendant cattle owner is liable only for the damage done by his cattle); State v. Wood, 59 N.J.L. 112, 113-14, 35 A. 654 (1896) (each dog’s trampling of the plaintiff’s cabbage patch is a separate harm; each owner is liable only for the harm his dog caused); King v. Ruth, 136 Miss. 377, 381,101 So. 500 (1924) (each dog owner is liable only for the damages done by his animals’ separate and distinct trespass). See also Cogswell v. Murphy, 46 Iowa 44 (1877) (reversing judgment against defendant cattle owners because of misjoinder of parties).
Apportionments of damages for indivisible harms are routinely made in cases involving the flooding of land from multiple sources. In Griffith v. Kerrigan, 109 Cal. App. 2d 637, 241 P.2d 296 (1952), a typical joint-flooding case, the plaintiff sued for damage to his peach orchard, caused by excessive underground water seepage from one defendant’s irrigation of an adjacent rice paddy, and from another defendant’s nearby canal. Id. at 638, 241 P.2d 296. The trial court entered judgment for the plaintiff against the remaining defendant for only the harm caused by that defendant. Id. Both parties appealed. On appeal, the plaintiff claimed that each defendant was the proximate cause of the entire harm, and therefore, she was entitled to a judgment for the entire amount of damages proved at trial. Relying on Restatement of Torts Section 881, the predecessor to Section 433A of the Second Restatement, the Griffith court rejected the plaintiff’s contention that damage and liability were entire. Id. at 639, 241 P.2d 296. The appellate court was satisfied that the estimates of the relative percentages of water from all possible sources were a sufficient evidentiary basis for making a reasonable apportionment of the damages. Id.
The defendants[2] in Griffith also appealed on grounds that the expert witness testimony given at trial established that no exact apportionment was possible. Because of this lack of precision, the defendants contended that the plaintiff had failed to carry his burden of proving each defendant’s causal role. Id. at 640, 241 P.2d 296. The appellate count expressly rejected the defendants’ contention and held that the expert witness’s estimate was a sufficient basis for the apportionment. Id.
The holdings in Griffith are based upon well-established precedents and principle of justice. Joint and several liability in such a case would allow “a plaintiff to overwhelm a defendant with claims for damages out of all proportion to his wrongdoing …” William Tackaberry Co. v. Sioux City Service Co.,154 Iowa 358, 377-78, 132 N.W. 945 (1911) (extensively reviewing authorities and rejecting joint and several liability for property damage caused by flooding from multiple causes; Boulger v. Northern Pacific Railroad Co., 41 N.D. 316, 324, 171 N.W. 632, (1918) (imposing entire liability on a party responsible for only a portion of the harm caused by a flood would be contrary to law and justice).
In Sellick v. Hall, 47 Conn. 260 (1879), the court held that regarding parties that independently damaged plaintiff’s property by flooding as joint tortfeasors was error. Id. at 273. Each party can be liable only for that portion of the harm, which he caused. Id. at 274. Although apportionment might be difficult in some cases, the court noted that juries are often entrusted with difficult factual judgments. Id. The plaintiff should not, therefore, be denied any recovery; nor should one defendant be “loaded with damages to not legally liable, simply because the exact ascertainment of the proper amount is a matter of practical difficulty.” Id.
The common law saw that any hardship to the plaintiff in not being able to assert joint and several liability was fairly mitigated by plaintiff’s being relieved of the requirement to prove the precise damage inflicted by each defendant. William Tackaberry Co. v. Sioux City Service, Co. 154 Iowa at 377, 132 N.W. 945; Griffith v. Kerrigan, 109 Cal. App. 2d. at 640, 241 P.2d 296. A reasonable basis for apportioning the single harm among multiple causes is sufficient to support an apportionment of damages. Sloggy v. Dilworth, 38 Minn. 179, 185, 36 N.W. 451 (1888) (rejecting entire liability; apportionment for damage to plaintiff’s crops caused by flooding from multiple causes may be based on the relative contribution of each party): Blaisdell v.Stephens, 14 Nev. 17, 19 (1879)(reversing joint judgment in a flooding case); Verheyen v. Dewey, 27 Idaho 1, 11-12, 146 P. 1116 (1915)(reversing joint judgment; each party should be responsible only for that portion of the flood that damaged plaintiff’s property): Ryan Gulch Reservoir Co. v. Swartz, 77 Colo. 60, 234 P. 1059, 1061 (1925) (rejecting joint liability for independent flooders of plaintiff’s land); Miller v. Highland Ditch Co., 87 Cal. 430, 431, 23 P. 550 (1891)(reversing joint judgment against defendants, whose irrigation ditches independently overflowed and deluged plaintiff’s land).
When two or more independent tortfeasors separately pollute the air or water and the consequences combine to form a single injury, each tortfeasor will be liable only for the consequences of his independent tortious act and will not be liable for the entire injury. Oakwood Homeowners Assoc. v. Maration Oil Co., 104 Mich. App. 689, 305 N.W.2d 567 (Mich. App. 1981). In Oakwood, the appellate court sustained the trial court’s jury instruction that the jury should separate the injuries caused to the plaintiff by the defendant from the injuries caused by other tortfeasors if they could do so.
“If two or more persons acting independently tortiously cause distinct harms or a single harm for which there is a reasonable basis for division according to the contribution of each, each is subject to liability only for the portion of the total harm that he himself caused.”
Oakwood Homeowners, 305 N.W.2d at 569.
In Maas v. Perkins, 42 W.2d 38, 253 P.2d 427 (Wash. 1953), the Supreme Court of Washington held that, while two alleged tortfeasors, accused of having contributed to the damage caused by oil sludge draining onto plaintiffs’ property, could be joined in one action, their liability was several and not joint. Plaintiffs would not be relieved of their burden that a particular defendant caused damage of a specified amount. Although the court admitted of the difficulty of such proof, the court required some basis for the allocation of the total damage. 42 W.2d 38, 253 P.2d at 430. The Maas decision followed the rule previously set out in Snavely v. City of Goldendale, 10 Wash. 2d 453, 117 P.2d 221 (1941, where a downstream farmer alleged that a municipality and a slaughterhouse discharged refuse into the Little Klickitat River. The court affirmed the rule that tortfeasors independently contributing to the pollution of a stream cannot be held jointly liable for the common injury. The basis of the court’s decision was fairness.
“[I]t might work great injustice to hold one responsible for the entire injurious effect of the pollution of a stream brought about by himself and others in varying degrees.”
Snavely, 117 P.2d at 224.
Courts have consistently viewed the rule of apportionment and several liability as a rule of fairness. Courts have been unwilling to impose liability on one tortfeasor for the acts of another over which the first had no control and where the only logical connection was some similarity of consequences.
In Farley v. Crystal Coal & Coke Co., 85 W.Va. 595, 102 S.E. 265 (1920), the Supreme Court of Appeals of West Virginia held that six separate mine operators, alleged to have polluted with slag, cinder and sewage the stream on which plaintiff’s farm was situated, could not be jointly liable for damage caused by the pollution:
“In the actual infliction of the injury there was nothing more than a combination, effected by natural causes of the consequences or results or the wrongful acts, in which the parties did not act. This of course does not absolve them from liability, but it does away with the ground or basis of joint liability and liability for entire damages. Each is liable only for the consequences of his own wrong and must be sued alone for the damages.”
Farley, 102 S.E. at 268.
Similarly, the court in Watson v. Pyramid Oil Co., 198 Ky. 135, 248 S.W. 227 (1923), was moved by considerations of fairness to adopt the rule of apportionment and several liability. Watson held that several refining companies could not be liable for the damage caused by each other’s operations. Otherwise, it reasoned “a defendant who had contributed to the injury in the slightest degree would be liable for all the damage caused by the wrongful acts of all the others.” 198 Ky. 135, 248 S.W. at 228.
In a case concerning noise pollution, the Georgia Court of Appeals held that a city operating an airport and the airlines using it were not jointly liable for damage caused to the plaintiff by a low flying aircraft. City of Atlanta v. Cherry, 84 Ga. App. 728, 67 S.E.2d 317 (Ga. App. 1951).
The Florida Supreme Court has held that joint liability would not be imposed on up-river phosphate producers despite the intermingling of the consequences of their tortious acts for the downstream riparian owners. Synnes v. Prarie Pebble Phosphate Co., 66 Fla. 27, 63 So. 1 (Fla. 1913); Standard Phosphate Co. v. Lunn, 66 Fla. 220, 63 So. 429 (Fla. 1913).
Apportionment, with burden on the plaintiff, was applied in personal injuries as well, at common law. In City of Mansfield v. Brister, 76 Ohio 270, 81 N.E. 631 (1907), the plaintiff, a riparian proprietor, sued the city for damage to his health caused by the pollution of Ritter’s Run. Ritter’s Run was found to have been fouled by five sewers, only one of which had been constructed by the city. The trial court instructed that jury that it was unnecessary to find that the city had caused the entire injury in order to find it liable for the damage. The Ohio Supreme Court deemed this error, and reversed. In a thoughtful opinion, the court discussed the contemporary authority. The court found the difficulty of apportionment presented no compelling reason to relieve the plaintiff from the obligation of proving that the damages sought from a defendant sprung from the act of that defendant:
“Each is liable only to the extent of the wrong committed by him. The fact that it is difficult to separate the injury done by each one from the others furnishes no reason for holding that one tortfeasor should be liable for act of others with whom he is not acting in concert.”
City of Mansfield, 76 Ohio 270, 81 N.E. at 633.
The suggestion of legal scholars that causal apportionment was a 20th century reform seems misguided. The mantra of “joint and several” has often clouded consideration of the fairness and practicality of causal apportionment in many kinds of personal injury cases.
[1] Michael D. Green, “Second Thoughts about Apportionment in Asbestos Litigation,” 37 Southwestern Univ. L. Rev. 531 (2008) (“The idea that liability is not all or nothing—a basic tenet of the common law—but could be apportioned in a fine-grained manner—that is using a scale of 100, whether you call it comparative negligence, fault, responsibility, or causation—is a reform of the twentieth century and one of the most influential in tort law of that century.”).
[2] Interesting how the procedure at that time put the defendants into the position that plaintiffs today take with respect to apportionment.
