I dissent.
The majority’s holding will deprive numerous plaintiffs suffering from so-called “latent” diseases caused by exposure to asbestos and other hazardous substances of full compensation for injuries inflicted by tortfeasors long before Proposition 51 went into effect. In my view, the majority’s reasoning and result are incorrect.
I.
In Evangelatos v. Superior Court (1988) 44 Cal.3d 1188 [246 Cal.Rptr. 629, 753 P.2d 585] (hereafter Evangelatos), we held that Proposition 51, which limits a tortfeasor’s liability for noneconomic damages to its percentage of fault, must apply prospectively only. A tortfeasor who caused an injury before Proposition 51’s effective date would continue to be subject to the traditional common law doctrine of joint and several liability. In so holding, we reaffirmed our seminal retroactivity decision, authored by Chief Justice Gibson, in Aetna Cas. & Surety Co. v. Ind. Acc. Com. (1947) 30 Cal.2d 388 [182 P.2d 159].
We explained: “ ‘ “[A] retrospective law is one which affects rights, obligations, acts, transactions and conditions which are performed or exist prior to the adoption of the statute." ’ [Citation.] ‘Since the industrial injury is the basis for any compensation award, the law in force at the time of the injury is to be taken as the measure of the injured person’s right of recovery.’ ” (Evangelatos, supra, 44 Cal.3d at p. 1206, quoting Aetna Cas. & Surety Co. v. Ind. Acc. Com., supra, 30 Cal.2d at pp. 391, 392.)
We emphasized: “Decisions of both the United States Supreme Court and the courts of our sister states confirm that the application of a tort reform statute to a cause of action which arose prior to the effective date of the statute but which is tried after the statute’s effective date would constitute a retroactive application of the statute.” (Evangelatos, supra, 44 Cal.3d at p. 1206, citing Winfree v. Nor. Pac. Ry. Co. (1913) 227 U.S. 296 [33 S.Ct. 273, 57 L.Ed. 518], and Joseph v. Lowery (1972) 261 Or. 545 [495 P.2d 273]; see also Landgraf v. USI Film Products (1994) 511 U.S. 244, 269-270 [114 *542S.Ct. 1483, 1499-1500, 128 L.Ed.2d 229] [in determining whether a statute operates “retrospectively” “the court must ask whether the new provision attaches new legal consequences to events completed before its enactment”]; Miller v. Florida (1987) 482 U.S. 423, 430 [107 S.Ct. 2446, 2451, 96 L.Ed.2d 351] [“A law is retrospective if it ‘changes the legal consequences of acts completed before its effective date.’ ”]; Un. Pac. R.R. Co. v. Laramie Stock Yards (1913) 231 U.S. 190, 199 [34 S.Ct. 101, 102, 58 L.Ed. 179] [a retroactive statute gives “a quality or effect to acts or conduct which they did not have or did not contemplate when they were performed”].)
We applied the general principle that legislation is presumed to operate only prospectively: “ ‘ “[T]he first rule of construction is that legislation must be considered as addressed to the future, not to the past. . . . The rule has been expressed in varying degrees of strength but always of one import, that a retrospective operation will not be given to a statute which interferes with antecedent rights . . . unless such be the ‘unequivocal and inflexible import of the terms, and the manifest intention of the legislature.’ ” [Citation.]”’ (Evangelatos, supra, 44 Cal.3d at p. 1207, italics added in Evangelatos.)
The majority now substantially overrule Evangelatos, by imposing, in effect, a scienter requirement for plaintiffs injured before Proposition 51 went into effect. The application vel non of the measure will no longer depend on “the law in force at the time of the injury.” (Evangelatos, supra, 44 Cal.3d at p. 1206.) Instead, it will turn on whether a plaintiff “was diagnosed with the disease for which damages are being sought, or otherwise discovered his illness or injuries” prior to the measure’s effective date. (Maj. opn., ante, at p. 525.)
Thus, under the majority’s new standard, the “ ‘ “rights, obligations, acts, transactions and conditions which are performed or exist prior to the adoption of the statute” ’ ” (Evangelatos, supra, 44 Cal.3d at p. 1206.) are no longer determinative of whether Proposition 51 applies. Even if a plaintiff establishes that he or she sustained a serious injury before the measure’s effective date, any damages from the tortfeasors who caused the injury may be subject to the measure’s damage limitations.
In my view, the majority err. The retrospective application of a provision should not depend solely on whether a plaintiff knew of his injury, and therefore had actual expectations based on prior law. As the United States Supreme Court instructed in Landgraf, “[a] statute does not operate ‘retrospectively’ merely because it. . . upsets expectations based on prior law.” (Landgraf v. USI Film Products, supra, 511 U.S. at p. 269 [114 S.Ct. at p. *5431499].) “Rather, the court must ask whether the new provision attaches new legal consequences to events completed before its enactment.” (Id. at pp. 269-270 [114 S.Ct. at p. 1499].)1
Consistent with Evangelatos, supra, 44 Cal.3d 1188, application of Proposition 51 should depend on when a wrongful act first gave rise to a cause of action for injury—i.e., when “ ‘the last element essential to the cause of action’ occurred].” (Spear v. California State Auto. Assn. (1992) 2 Cal.4th 1035, 1040 [9 Cal.Rptr.2d 381, 831 P.2d 821].) The dispositive question, therefore, should be whether a plaintiff had existing rights based on an injury prior to the effective date of the measure—not whether he or she knew it.
As stated in an analogous case, also involving the application of a statutory change in the laws governing personal injury actions: “‘Logic dictates that a plaintiff cannot bring a cause of action until he knows or reasonably should know of his injury, and also knows or reasonably should know that the injury was caused by the wrongful acts of another. However, that does not mean that the plaintiff does not have an existing cause of action of which he is unaware.'” (Fetzer v. Wood (1991) 211 Ill.App.3d 70 [155 Ill.Dec. 626, 569 N.E.2d 1237, 1243].)
I agree with the Court of Appeal that we should properly measure when a plaintiff had an existing cause of action from the time exposure to asbestos first resulted in a “compensable” injury from pleural mesothelioma. As we have previously observed, to be “compensable,” injury must have resulted in something more than “nominal damages, speculative harm, or the threat of future harm—not yet realized.” (Budd v. Nixen (1971) 6 Cal.3d 195, 200 [98 Cal.Rptr. 849, 491 P.2d 433].)
The critical question, therefore, in a case involving a latent injury from exposure to asbestos is: When was the injury first “compensable”? To answer that question, I would slightly paraphrase Justice Corrigan’s views on this point, in one of the several cases presently under review, as follows.
When exposure to a toxic substance causes cancer in an individual, that person is injured or harmed by the acquisition of the disease, whether or not he is aware of its presence. A contrary conclusion runs counter to the accepted usage of the term “injury.” The opinion in Aetna Cas. & Surety Co. v. Ind. Acc. Com., supra, 30 Cal.2d at pages 391-392, suggested as much by expressly rejecting a contention that a new compensation rule could be *544applied prospectively, as long as it was in effect not when the industrial accident occurred, but later, when the resulting disability became “manifest.”
I would distill the following rule. An individual sustains an “injury,” for purposes of Proposition 51, when he has undergone a physiological change that will, to a reasonable degree of medical certainty, result in a condition giving rise to the cause of action. At that point, the tortfeasor’s actions have harmed the plaintiff by causing a detrimental physical condition. Whether the plaintiff is aware of it or not, he is no less injured. Under this test, a cause of action does not ‘accrue’ at the point of mere exposure to or inhalation of asbestos fibers, because many who are exposed will never suffer a compensable injury. Neither would a nondetrimental physiological reaction to asbestos exposure constitute accrual. On the other hand, under this definition a cause of action may, under specific circumstances, accrue for purposes of Proposition 51 application before the plaintiff is diagnosed or diagnosable.
The analytic difficulty in these cases is that the point at which compensable harm has been suffered will always have to be evaluated in retrospect. According to expert testimony given in this case, an individual will not be diagnosable with mesothelioma for some 10 to 15 years after his cells have embarked upon an irreversible progression towards the disease, which is invariably fatal. At the point of that initial cellular change, the individual has experienced no symptoms and, because he is unaware of his condition, has suffered no associated emotional distress or compensable fear of cancer. He has, however, suffered a serious functional impairment of his cells. Moreover, from that point onward, absent some intervening illness or accident, that impairment will shorten his lifespan. We think such an impairment is compensable.
It could be argued that damages for such harm are speculative because an individual could die of unrelated causes in the decade or more between the initial cellular changes and the manifestation of mesothelioma. In the unique context in which these cases arise, however, it will be beyond argument that the plaintiff has, in fact, survived long enough to manifest the disease. In choosing between a policy that would ignore the reality of an injury because it was not immediately apparent and one that would recognize harm proven to exist by expert medical testimony based on all relevant information, we believe conventional tort analysis augurs in favor of the latter.
I also reject the argument of Owens-Coming Fiberglas Corporation here that application of Proposition 51 should depend on when a plaintiff “discovered” an injury—not on when it occurred—by analogy to the statutory *545provisions and judicially developed rules tolling the statute of limitations for certain actions until “discovery.” (See 3 Witkin, Cal. Procedure (4th ed. 1996) Actions, § 463, pp. 583-584.) The analogy is ill-conceived. Such tolling provisions are exceptions to the general rule that the statute of limitations begins to run when a cause of action arises—i.e., when facts exist to support each of its elements—“despite the plaintiff’s ignorance of his cause of action or the identity of the wrongdoer.” (Id., § 460, at pp. 581-582.) Their purpose—to avoid the unfairness of allowing the time for commencing an action to expire before a plaintiff learns of an existing cause of action—is irrelevant to the retroactivity question we resolved in Evangelatos. As the Court of Appeal below observed, applying a “discovery” rule in this context “is trying to insert a square peg into a round hole.” Indeed, Owens-Coming’s analogy is particularly inapt to asbestos cases, in which the statute of limitations is tied not to “discovery” but to “disability” and, thus, may not commence until long after a plaintiff learned of his or her injury and its cause.2
The majority conclude that application of Proposition 51 should depend on when a plaintiff “discovered” the injury—not on when it occurred— because “[t]he parties’ reasonable reliance on the laws governing recovery for personal injuries was of paramount concern in our determination in Evangelatos to declare Proposition 51 prospective only.” (Maj. opn., ante, at p. 531, italics added.) They reason that there could be no “reasonable reliance” on pre-Proposition 51 joint and several liability rules unless a plaintiff knew about the injury before the measure went into effect.
They are wrong. Evangelatos referred to the parties’ “reasonable reliance” as one policy rationale for the presumption against retroactivity of the measure, but it was not of “paramount concern.” The core basis for our holding was the principle articulated in Aetna Cas. & Surety Co. v. Ind. Acc. Com., supra, 30 Cal.2d at page 392, that “ ‘the law in force at the time of the injury is to be taken as the measure of the injured person’s right of recovery.’ ” (Evangelatos, supra, 44 Cal.3d at p. 1206.) As discussed, that overriding principle requires that parties are bound by the rules in effect at the time of the injury, i.e., by the legal rights and obligations that existed when the action arose. It would be especially inappropriate to impose a *546“discovery” requirement in cases involving asbestos-related injury when one of the chief reasons for the lack of “discovery” by plaintiffs like James Buttram was that tortfeasors willfully suppressed information concerning the facts of, and dangers from, exposure to asbestos.3
II.
In the present case, the trial court found, on the basis of evidence that included the unrebutted expert testimony by a physician specializing in pulmonary diseases that Buttram probably had cancer cells “on the order of seven years before” he was diagnosed with pleural mesothelioma in 1991. Like the Court of Appeal, I agree that this expert testimony constituted reasonably reliable evidence that Buttram sustained a compensable injury— and, thus, had an existing cause of action—well before the effective date of Proposition 51.
For these reasons, I would affirm the judgment of the Court of Appeal.
Respondent’s petition for a rehearing was denied October 15, 1997. Mosk, J., was of the opinion that the petition should be granted.
Logically, the events giving rise to legal consequences are “completed” at the time a plaintiff sustains an injury in fact. Thus, a cause of action arises at the time when a plaintiff sustains such an injury—even if it is not yet manifested or diagnosed.
The time for commencing an action for injury based on exposure to asbestos is the later of the following: “(1) Within one year after the date the plaintiff first suffered disability. [ID (2) Within one year ¿ter the date the plaintiff either knew, or through the exercise of reasonable diligence should have known, that such disability was caused or contributed to by such exposure.” (Code Civ. Proc., § 340.2, subd. (a).) “Disability” is defined as “the loss of time from work as a result of such exposure which precludes the performance of the employee’s regular occupation.” (Id., subd. (b).) The limitations period is, thus, not linked to any element of the plaintiff’s cause of action.
In this matter, for example, the jury found that “[u]se of an asbestos-containing product manufactured, supplied or distributed by Owens-Coming Fiberglas involved a substantial danger known or knowable to Owens-Coming Fiberglas that would not be readily recognized by the ordinary consumer of the product” and that it “failed to give an adequate warning of the danger.” The jury also found “[b]y clear and convincing evidence, Owens-Coming Fiberglas acted with malice or fraud.”