Court Opinion

ID: 9796363
Source: CourtListenerOpinion
Date Created: 2023-08-31 03:56:15.631113+00
Date Added: 2024-06-11T08:50:10.366115
License: Public Domain

MORENO, J., Concurring and Dissenting.
I join parts I and II of the lead opinion, holding that there is no per se bar to class treatment of medical monitoring claims, and concluding that plaintiffs have demonstrated some common issues as a class. However, I dissent from the,, lead opinion’s holding in parts III and IV that the trial court abused its discretion in finding that common issues predominate and in certifying the class in this case. Contrary to the majority, I conclude that the trial court did not abuse its discretion in certifying the class of plaintiffs seeking damages for the cost of future medical monitoring.
Plaintiffs in the present case allege that defendants caused contaminants, including toxic rocket fuel (ammonium perchlorate) and trichloroethylene (a carcinogenic solvent) to be leaked into the water table in Redlands and that this contaminated water was consumed by members of the proposed class. Plaintiffs brought a claim seeking damages for the cost of a court-supervised medical monitoring program, and punitive damages. The trial court determined that plaintiffs had a realistic chance of success on the merits. In addition, the trial court found that common issues predominate in this action and that plaintiffs could pursue their claims as a class.
The decision of a trial court to certify a class action is reviewed for abuse of discretion. “Because trial courts are ideally situated to evaluate the *1119efficiencies and practicalities of permitting group action, they are afforded great discretion in granting or denying certification.” (Linder v. Thrifty Oil Co. (2000) 23 Cal.4th 429, 435 [97 Cal.Rptr.2d 179, 2 P.3d 27] (Linder)) The majority disregards this deferential standard of review and instead engages in its own examination of the record to decide that, while there are some common issues in this case, these issues do not predominate. The majority concludes, therefore, that the trial court erred in certifying the class. I believe that substantial evidence supports the trial court’s certification order. Because I would uphold the trial court’s decision to certify the class in this case, I dissent.
I.
A. Applicable Standard of Review
The lead opinion briefly summarizes the standard for reviewing a trial court’s decision to certify a class. (See lead opn., ante, at p. 1106.) This short discussion, however, does not fully acknowledge the level of deference given to a trial court. The lead opinion cites our opinion in Linder, supra, 23 Cal.4th at page 436, for the proposition that “we must examine the trial court’s reasons for [granting] class certification.” The lead opinion does not mention, however, that in the following sentence in Linder we clarify that “ ‘Any valid pertinent reason stated will be sufficient to uphold the order.’ ” (Ibid) Thus, while the lead opinion is correct in stating that reviewing courts may overturn a trial court ruling on certification if it is not supported by substantial evidence, it misses the point that any valid pertinent reason is sufficient to uphold an order for certification. This is an extremely deferential standard of review.
Further, we have stated that “a trial court ruling [on certification] supported by substantial evidence generally will not be disturbed ‘unless (1) improper criteria were used [citation]; or (2) erroneous legal assumptions were made [citation].’ ” (Linder, supra, 23 Cal.4th at pp. 435-436.) For example, in Washington Mutual Bank v. Superior Court (2001) 24 Cal.4th 906, 927 [103 Cal.Rptr.2d 320, 15 P.3d 1071] (Washington Mutual), we reversed a Court of Appeal decision upholding the trial court’s certification order because the order was “premised upon [a] faulty legal assumption.” In the present case, however, the majority does not conclude that the trial court used improper criteria in granting the certification order, nor do they find that the trial court made erroneous legal assumptions. In such a case, “the sole question is whether the court abused its discretion.” (Occidental Land, Inc. v. Superior Court (1976) 18 Cal.3d 355, 361 [134 Cal.Rptr. 388, 556 P.2d 750].)
*1120In addition, an appellate court’s review of a certification order should not consider the merits of the underlying suit. As we have said, “we view the question of certification as essentially a procedural one that does not ask whether an action is legally or factually meritorious.” (Linder, supra, 23 Cal.4th at pp. 439-440.) In reviewing a certification order, then, we assume that the plaintiffs’ theories of liability are viable. Any challenge to the viability of the plaintiffs’ claims should be left for a pleading or motion that considers the merits of these claims. As we have stated, “[w]hen the substantive theories and claims of a proposed class suit are alleged to be without legal or factual merit, the interests of fairness and efficiency are furthered when the contention is resolved in the context of a formal pleading (demurrer) or motion (judgment on the pleadings, summary judgment, or summary adjudication) that affords proper notice and employs clear standards. Were we to condone merit-based challenges as part and parcel of the certification process, similar procedural protections would be necessary to ensure that an otherwise certifiable class is not unfairly denied the opportunity to proceed on legitimate claims.” (Id. at pp. 440-441.)
B. Trial Court’s Certification Order
In the certification order at issue here, the trial court explained that while it recognized that this case presents some individual issues, these issues were “manageable.” The trial court found that plaintiffs’ case derived from a common nucleus of facts and that common issues predominate. Because we review the certification order for abuse of discretion, I set forth in detail its relevant contents.
In granting the certification order, the trial court stated that its ruling was interlocutory: “This order may be rescinded or modified as the changed circumstances of the class, its representatives, or particular actions require.” After concluding that plaintiffs have a realistic chance of success on the merits, and recognizing that plaintiffs allege that they were exposed as a class to water contaminated by toxic chemicals, the court noted: “This court further finds that although there is no evidence of the dosage of toxins that were received by the members of the proposed class, proof of dosage received is not necessary at this time.” Additionally, the court found that “it is not necessary to determine the levels of toxins received by each plaintiff at this time.”
Most importantly, the trial court found that “[t]he issues of law and fact in this case all evolve from a common nucleus of facts and these common questions of law and fact predominate over those that are individual to the plaintiffs, [f] The court recognizes that there are individual issues that will *1121have to be dealt with at the time of trial, however, the court finds these individual issues to be manageable.”
Turning to the benefits of class treatment, the trial court found that “proceeding with this action as a class action will substantially benefit the court and the litigants because it will provide a superior method of dealing with the common questions of law and fact that exist in this case.” The trial court noted that it had “considered other methods of proceeding with this litigation” but found that “the class action is the superior method.”
In addition, the trial court found that the prerequisites for a class action set forth in Federal Rules of Civil Procedure, rule 23(a) (28 U.S.C.), were satisfied. We have stated that in determining whether a class action proponent has demonstrated a predominance of common issues and manageability of the class, “we may look to the procedures governing federal class actions under rule 23 of the Federal Rules of Civil Procedure (28 U.S.C.) . . . for guidance.” (Washington Mutual, supra, 24 Cal.4th at p. 922.) The trial court in this case found that “(1) The class consists of an estimated 50,000 - 100,000 people and therefore, the members of the class are so numerous that joinder of members of the class as individual plaintiffs is impracticable; (2) The common questions of law and fact predominate over those that are individual to the plaintiffs; (3) The claims of the persons representing the class are typical of the class generally; (4) The persons acting as class representatives are able to fairly and adequately protect the interest of all members of the class and class counsel is able to adequately represent the class.”
II.
Applying the standard of review to the trial court’s certification order, it is clear that the trial court did not abuse its discretion in certifying the class in this case. Contrary to the majority, I conclude that substantial evidence supports the trial court’s determination that common issues predominate and that any individual issues in this case are manageable.
A. Duty and Breach
In reviewing the factors that plaintiffs will have to prove at trial to recover medical monitoring damages, there is substantial evidence to support the trial court’s conclusion that common issues predominate. Part II of the lead opinion recognizes that it is undisputed that several key issues at trial will be proven by evidence that is common to all class members. (Lead opn., ante, at pp. 1106-1108.) As the lead opinion states, because plaintiffs’ claims sound *1122generally in negligence, plaintiffs will have to prove duty, breach of duty, proximate cause, and damages. (Artiglio v. Corning Inc. (1998) 18 Cal.4th 604, 614 [76 Cal.Rptr.2d 479, 957 P.2d 1313].) The lead opinion acknowledges that the issue of whether defendants owed a duty of care to the proposed class members is susceptible to common proof. (Lead opn., ante, at pp. 1106-1107.) In addition, the lead opinion states that the issue of defendants’ breach of this duty of care is also one that will be proven by evidence common to all class members. (Ibid.)
The trial court, in its certification order, explained that it found that common issues predominate because “[t]he issues of law and fact in this case all evolve from a common nucleus of facts.” This conclusion is supported by substantial evidence since the central question of whether defendants acted negligently is common to all class members. In order to establish defendants’ liability, plaintiffs will present common evidence attempting to show that defendants negligently disposed of toxic chemicals that contaminated the groundwater of Redlands. Evidence of how these chemicals were discharged, and in what amounts, and how they entered into the domestic water system, will be common to all class members. In fact, all of defendants’ actions will be proven by common evidence.
B. Proximate Cause and Damages: The Potter Factors
In addition to establishing defendants’ duty of care and their breach of this duty, plaintiffs will also have to show that their injuries were proximately caused by defendants’ actions and that they are entitled to damages as compensation for these injuries. Plaintiffs in this case, however, do not seek traditional compensatory damages. Instead, they seek to recover damages for the cost of medical monitoring of future injuries. As we explained in Potter, “[i]n the context of a toxic exposure action, a claim for medical monitoring seeks to recover the cost of future periodic medical examinations intended to facilitate early detection and treatment of disease caused by a plaintiff’s exposure to toxic substances.” (Potter v. Firestone Tire & Rubber Co. (1993) 6 Cal.4th 965, 1004-1005 [25 Cal.Rptr.2d 550, 863 P.2d 795] (Potter).)
Damages for medical monitoring are unlike a traditional damages remedy because in order to recover medical monitoring damages, a plaintiff need not demonstrate a present physical injury or even show proof that injury is reasonably certain to occur in the future. We have determined that “medical monitoring may be called for as a result of defendant’s tortious conduct, even in the absence of actual physical injury.” (Potter, supra, 6 Cal.4th 965, 1007.) “[R]ecovery of medical monitoring damages should not be dependent upon a showing that a particular cancer or disease is reasonably certain to *1123occur in the future.” (Id. at p. 1008.) To recover medical monitoring damages, a plaintiff must show that “the need for future monitoring is a reasonably certain consequence of a plaintiffs toxic exposure and that the recommended monitoring is reasonable.” (Id. at p. 1009.)
As the lead opinion explains, we set forth five factors in our decision in Potter (the Potter factors) that are relevant to a court’s determination of the reasonableness and necessity of medical monitoring. (Potter, supra, 6 Cal.4th at p. 1009; see lead opn., ante, at p. 1103.) The five Potter factors are not novel evidentiary burdens; they are simply meant to give courts guidance in determining whether plaintiffs seeking medical monitoring have met the traditional tort requirements of causation and damage. (See lead opn., ante, at p. 1105.) Thus, plaintiffs will need to present evidence relating to the Potter factors in order to prove the elements of proximate causation and damages.
As with the elements of duty and breach, I agree with the majority that some of the Potter factors are clearly subject to common proof. The majority recognizes that two of the five Potter factors—the toxicity of the chemicals allegedly discharged and the seriousness of a disease for which the plaintiffs are at risk—will involve common proof.
Furthermore, the lead opinion acknowledges that “[sjtrictly speaking,” the trial court was correct in ruling that the first Potter factor—the significance and extent of plaintiffs’ exposure to chemicals—is subject to common proof, since under plaintiffs’ theory of liability, the exact dosage of each discharged chemical received by each individual plaintiff is irrelevant. (Lead opn., ante, at p. 1108.) Part III of the lead opinion, however, ultimately rejects plaintiffs’ theory of liability and concludes that the first Potter factor is not subject to common proof. It is largely this determination, that the issue of plaintiffs’ exposure is not subject to common proof, that leads the majority to reject the trial court’s conclusion that common issues predominate. For this reason, I will focus on this factor to explain why I believe that the issue of exposure is subject to common proof, and that the trial court did not err in concluding that common issues predominate.
The lead opinion refers to Potter for the proposition that “evidence of exposure alone cannot support a finding that medical monitoring is a reasonably necessary response.” (Lead opn., ante, at pp. 1108-1109, citing Potter, supra, 6 Cal.4th at p. 1009.) This statement is, of course, correct. A plaintiff cannot recover the cost of medical monitoring merely because he or she has been exposed to toxic chemicals. Instead, a plaintiff must show the need for medical monitoring in light of the other Potter factors, including the *1124toxicity of these chemicals and the seriousness of the diseases for which plaintiff is at risk as a result of the exposure to these chemicals.
The lead opinion is incorrect, however, in concluding from our statements in Potter that the issue of plaintiffs’ exposure to toxic chemicals cannot be subject to common proof. We did not decide in Potter whether evidence of exposure could be presented on a class-wide basis. We merely said that one factor relevant in determining whether a plaintiff could recover the cost of medical monitoring was the significance and extent of plaintiff’s exposure to the toxic chemicals. We did not say whether or not plaintiffs could present evidence of exposure on a class-wide basis by alleging that all plaintiffs in a proposed class have received a certain minimum level of exposure to the chemicals.
Plaintiffs’ theory of liability is that all individuals who meet the class requirements are entitled to medical monitoring. Plaintiffs allege that everyone exposed to defendants’ discharged chemicals over specified minimum safety levels “for some part of a day, for greater than 50% of a year, for one or more years from 1955 to the present” will require specialized monitoring for diseases caused by such exposure. Class membership, therefore, is restricted by definition to persons who have received a specified, medically significant minimum level of exposure to the allegedly contaminated water. Plaintiffs claim that individual class members need only establish their residency and/or employment in the contaminated area for at least six months to be eligible for medical monitoring. Thus, under plaintiffs’ theory of liability, the significance and extent of toxic exposure is susceptible to common proof. While plaintiffs may or may not be able to succeed in proving this theory, the trial court was correct in accepting this theory for purposes of a certification motion.
The majority concludes, however, that plaintiffs cannot prove exposure on a class-wide basis because each plaintiff received different dosages of toxic chemicals. (See lead opn., ante, at p. 1109.) Of course, whether someone is exposed to toxic chemicals is not the same issue as what dosage of the chemical he or she received. I agree with the majority that any relevant questions relating to variations in actual chemical dosage received by individual members of the plaintiff class are likely not susceptible to common proof. Plaintiffs, however, have constructed their theory of liability to make these questions of individual dosage largely irrelevant.
The majority errs in examining the record in this case to determine whether plaintiffs’ experts’ declarations support plaintiffs’ theory of liability. The lead opinion, finds that “the medical expert testimony plaintiffs *1125presented in support of their motion for class certification is too qualified, tentative and conclusionary to constitute substantial evidence that plaintiffs, by adopting a liability theory that makes actual dosages and variations in individual response irrelevant, will be able to prove causation and damages by common evidence.” (Lead opn., ante, at p. 1111.) This type of reevaluation of the record and critique of expert testimony is inappropriate in the context of a certification motion.
In reviewing a certification order, we are not called upon to determine whether plaintiffs’ experts’ declarations demonstrate the reasonableness and necessity of medical monitoring.1 Whether the evidence submitted in support of certification is adequate to support plaintiffs’ theories on their merits is not before us, since certification may not be “conditioned upon a showing that class claims for relief are likely to prevail.” (Linder, supra, 23 Cal.4th at p. 443.)
By rejecting the viability of plaintiffs’ theory of liability—that all plaintiffs in the proposed class are entitled to medical monitoring based on a threshold level of exposure—the majority is effectively ruling on the substantive merits of plaintiffs’ claims in the context of a procedural motion for certification. Such a conclusion should not be made in the context of a certification motion but rather should be made in the context of a formal pleading or motion that affords proper notice to the parties and follows clear standards of review. By ruling on the merits of plaintiffs’ claims in the context of a certification motion, the majority denies plaintiffs the procedural protections to which they are entitled. (Linder, supra, 23 Cal.4th at p. 440.)
In addition, the majority’s search of the record for evidence to support plaintiffs’ theory of liability risks making a motion for certification a more complicated and burdensome procedure. As we have cautioned, “[substantial discovery . . . may be required if plaintiffs are expected to make meaningful presentations on the merits. All of that is likely to render the certification process more protracted and cumbersome, even if . . . trial courts were prohibited from resolving factual disputes. Such complications hardly seem necessary when procedures already exist for early merit challenges.” (Linder, supra, 23 Cal.4th at p. 441, fn. omitted.)
*1126Furthermore, the majority ignores the fact that the nature of the remedy requested in this case reduces the importance of each plaintiffs individual exposure. If plaintiffs had sought to recover compensatory damages, the issue of each individual’s exposure clearly would have been relevant to each individual’s recovery. In seeking medical monitoring damages, however, plaintiffs need not prove present or future individual injury. Instead, they need only show that medical monitoring is reasonably necessary as a result of exposure to the toxic chemicals. Plaintiffs allege that all class members, having received a threshold level of exposure, are entitled to the same remedy because they are all at a greater risk of disease. This is the approach taken in Yslava v. Hughes Aircraft Co. (D.Ariz. 1993) 845 F.Supp. 705, where the court determined that for a class action seeking medical monitoring, “[a]ll persons who were exposed to [a certain] level for at least a year would qualify for medical monitoring. Thus, proof of an exact or individual amount of exposure or particular risk level is not necessary. The core issues of liability and exposure are common to all class members.” (Id. at p. 713, italics added.)
Ultimately, the majority, in rejecting plaintiffs’ theory of liability, fails to give proper deference to the findings of the trial court. The trial court accepted plaintiffs’ theory of liability for purposes of the certification order. As the trial court concluded, “although there is no evidence of the dosage of toxins that were received by the members of the proposed class, proof of the dosage received is not necessary at this time.” Moreover, the certification order was interlocutory. Thus, should plaintiffs’ theory of liability prove to be not viable at a later date, the trial court retained the option of decertifying the class. (See O’Connor v. Boeing North American, Inc. (C.D.Cal. 2000) 197 F.R.D. 404, 408-409 [while trial court initially certified class seeking damages for medical monitoring, the court decertified the class after its summary judgment rulings].) At this early point in the proceedings, however, the trial court assumed, as it should, that plaintiffs’ theory of liability was viable. Under this theory, the first Potter factor—plaintiffs’ exposure to the toxic chemicals—is subject to common proof.
Turning to the remaining Potter factors, the lead opinion briefly states that proof of each individual plaintiff’s chances of developing a particular disease, had he or she not been exposed, may not be subject to common proof. I agree with the lead opinion that an individual’s preexisting conditions are, by definition, not susceptible to common proof. I am not convinced, however, that predisposition to a disease should preclude a plaintiff who has been exposed to toxic chemicals from receiving medical monitoring for diagnostic purposes. As we stated in Potter, “While there is no question that a defendant ought not to be liable for medical monitoring of a plaintiff’s *1127preexisting condition that is unaffected by a subsequent toxic exposure negligently caused by the defendant, we see no reason why the defendant should not be held responsible for any increased or different monitoring of the preexisting condition (whether or not the preexisting condition is caused by the plaintiff’s voluntary conduct) where necessitated as a direct result of the subsequent exposure.” (Potter, supra, 6 Cal.4th at p. 1009, fn. 27.) Thus, neither the possibility nor the actuality of preexisting medical conditions constitutes a bar to medical monitoring liability. Furthermore, screening for preexisting conditions, while individualized, is irrelevant to an initial determination of defendants’ liability. Such screening for preexisting conditions can be done postjudgment, perhaps as an initial part of the monitoring process.
Finally, the lead opinion does not discuss the fifth Potter factor, the clinical value of early detection and diagnosis. (Potter, supra, 6 Cal.4th at p. 1009.) Presuming that the clinical value of early detection and diagnosis varies among diseases, whether monitoring has clinical value in a particular case would seem to depend, at least in part, on the specific toxicity of the chemicals allegedly discharged. As previously discussed, the lead opinion agrees that such toxicity may be susceptible to common proof.
Part I of the lead opinion states that even if one Potter factor is not subject to common proof, this should not prove fatal to a certification motion. The lead opinion explicitly rejects defendants’ argument that Potter requires that each of the five factors is capable of common proof. (See lead opn., ante, at p. 1105.) I agree with this conclusion and determine that even though some factors may not involve common proof, certification of a class action may still be appropriate. As we have stated, “the fact that each member of the class must prove his [or her] separate claim to a portion of any recovery by the class is only one factor to be considered in determining whether a class action is proper” and “[t]he requirement of a community of interest does not depend upon an identical recovery.” (Vasquez v. Superior Court (1971) 4 Cal.3d 800, 809 [94 Cal.Rptr. 796, 484 P.2d 964, 53 A.L.R.3d 513] (Vasquez).) Even “that each class member might be required ultimately to justify an individual claim does not necessarily preclude the maintenance of a class action.” (Collins v. Rocha (1972) 7 Cal.3d 232, 238 [102 Cal.Rptr. 1, 497 P.2d 225]; see also Vasquez, supra, at p. 815.)
Here, the trial court concluded that class treatment was the superior method since the case arose out of a common nucleus of facts and common issues predominate. In my view, substantial evidence supports this conclusion. I agree with the majority that the issues of defendants’ duty and breach of this duty is susceptible to common proof. In addition, I conclude that *1128most, if not all, of the Potter factors will involve proof that is common to all class members. Therefore, unlike the majority, I cannot conclude that the trial court abused its discretion in determining that common issues predominate.
III.
While the majority concludes that there is no per se bar to class treatment of medical monitoring claims, I am concerned that by reversing the trial court’s decision to certify the class in this case, the effect of our ruling will be a de facto bar on class treatment of medical monitoring claims. Plaintiffs’ theory of liability is that all plaintiffs who meet a threshold level of exposure should recover damages for the cost of medical monitoring. The majority rejects this theory, agreeing with defendants that proof of exposure alone is insufficient to show causation and damages. Since the majority believes that each plaintiff will have to show the specific dosage of toxic chemicals he or she received, they conclude that the trial court erred in certifying this case as a class action. My concern with this holding is that it essentially precludes plaintiffs from constructing a claim for medical monitoring damages that minimizes questions of individual exposure. If plaintiffs are required to show evidence of dosage on an individual basis, and such a requirement of individualized proof will prove fatal to a certification motion, then essentially no claim for medical monitoring damages can be treated on a class-wide basis.
In every potential class action for medical monitoring damages, exposure will be individualized in some sense. A group of plaintiffs seeking medical monitoring based on their exposure to asbestos in the workplace, for example, will have been employed for varying amounts of time. Even for those plaintiffs employed for the same length of time, contact with hazardous substances may vary from plaintiff to plaintiff. Under the majority’s holding, these employees could not bring a class action for medical monitoring damages because each class member did not receive an identical exposure to the asbestos. Even if the employees attempted to bring an action for medical monitoring damages based on a minimum level of exposure, the majority would require each plaintiff to prove his or her individual level of exposure, and would conclude that, as a result, common issues do not predominate and the class could not be certified. Ultimately, by rejecting plaintiffs’ theory of liability in the present case and concluding that common issues do not predominate, the majority risks barring class treatment for any medical monitoring claim. (Cf. Lamb v. United Security Life Company (S.D. Iowa 1972) 59 F.R.D. 25, 33 [to reject class actions for securities fraud merely because of the existence of the individual reliance issue would “wholly eviscerate Rule 10b-5”].)
*1129IV.
Contrary to the majority, I believe that this case is ideally suited for class treatment. The majority’s failure to uphold the trial court’s decision to certify the class in this case is contrary to the public policy of this state. As we have said, “this state has a public policy which encourages the use of the class action device.” (Richmond v. Dart Industries, Inc. (1981) 29 Cal.3d 462, 473 [174 Cal.Rptr. 515, 629 P.2d 23].) Class actions “ ‘serve an important function in our judicial system. By establishing a technique whereby the claims of many individuals can be resolved at the same time, the class suit both eliminates the possibility of repetitious litigation and provides small claimants with a method of obtaining redress for claims which would otherwise be too small to warrant individual litigation.’ ” (Id. at p. 469.)
By allowing plaintiffs to pursue their claims as a class, the trial court’s certification order may advance a number of public policies. In Potter, we found that “recovery of medical monitoring costs is supported by a number of sound public policy considerations.” (Potter, supra, 6 Cal.4th at p. 1008.) We listed four public policy reasons supporting medical monitoring damages: (1) the “important public health interest in fostering access to medical testing for individuals whose exposure to toxic chemicals creates an enhanced risk of disease, particularly in light of the value of early diagnosis and treatment for many cancer patients”; (2) the “deterrence value in recognizing medical surveillance claims” because allowing plaintiffs to recover the cost of care could deter the irresponsible discharge of toxic chemicals; (3) the mitigation of future illness and therefore the reduction of overall costs that could result from providing medical monitoring before the consequences of exposure are manifest; (4) the fact that “it would be inequitable for an individual wrongfully exposed to dangerous toxins, but unable to prove that cancer or disease is likely, to have to pay the expense of medical monitoring when such intervention is clearly reasonable and necessary.” (Ibid)
I agree with the trial court that plaintiffs’ claims for medical monitoring damages are most effectively and efficiently presented as a class action. Plaintiffs allege that they were injured by defendants as a class. As claimed by plaintiffs, defendants negligently disposed of toxic rocket fuel, which seeped into the groundwater of Redlands and contaminated the city’s drinking water. The majority holds that notwithstanding this class-wide injury, plaintiffs cannot recover as a class. Instead, they must pursue their claims on an individual basis. In order to recover the cost of medical monitoring for risks of diseases allegedly caused by defendants’ negligent actions, each *1130plaintiff will have to prove the elements of a damages claim. Each plaintiff will have to show that defendants had a duty of care, that defendants breached this duty by negligently disposing of toxic chemicals, and that the chemicals contaminated the groundwater. He or she will additionally have to show the amount of contaminants that entered the groundwater, and when, where, and at what levels the contaminants were pumped by the city’s wells and introduced into the domestic water system. Each plaintiff will have to prove the toxicity of the chemicals, and the diseases he or she is at risk of contracting as a result of exposure to the chemicals. Each plaintiff will have to show that medical monitoring of future potential diseases is a reasonably necessary response based on the risk of disease due to exposure to the chemicals.
Absent class treatment, therefore, each individual plaintiff will present the same or essentially the same arguments and evidence (including expert testimony) on these numerous complicated issues. Any Redlands resident who wishes to recover the cost of medical monitoring will have to go to great expense to prove defendants’ liability and his or her right to recover. The result will be a multiplicity of trials conducted at enormous cost to both the judicial system and the litigants. As Chief Judge Weinstein observed in In re “Agent Orange” Product Liability Litigation (E.D.N.Y. 1983) 100 F.R.D. 718, 720, “[i]f [mass injury] claims are dealt with individually, the result might [be] \ . . a tedium of repetition lasting well into the next century.’” “It would be neither efficient nor fair to anyone, including defendants, to force multiple trials to hear the same evidence and decide the same issues.” (Boggs v. Divested Atomic Corp. (S.D. Ohio 1991) 141 F.R.D. 58, 67 (Boggs).)2 Class treatment here therefore promotes judicial efficiency and economy.
More importantly, it is unlikely that, on an individual basis, plaintiffs will pursue such a remedy. Class claims for medical monitoring damages typically present a large body of plaintiffs who, individually, do not expect a large recovery, but, as a class, expect a significant recovery. “Where it is not economically feasible to obtain relief [in separate suits] . . . , aggrieved persons may be without any effective redress unless they may employ the class-action device.” (Deposit Guaranty Nat. Bank v. Roper (1980) 445 U.S. *1131326, 339 [100 S.Ct. 1166, 1174, 63 L.Ed.2d 427].) As we have stated, “[w]hile the mere denial of certification does not, as a legal matter, terminate the right of any plaintiff to pursue claims on an individual basis, it is likely to have that net effect when there has been injury of insufficient size to warrant individual action.” (Linder, supra, 23 Cal.4th at p. 441.) In the present case, the cost of litigating defendants’ liability undoubtedly will be greater than any expected individual recovery in the form of damages for the cost of medical monitoring. For “exposure only” plaintiffs individually to pursue even plainly meritorious medical monitoring claims may be economically infeasible.
Furthermore, class treatment of plaintiffs’ claims would secure uniform results for any viable medical monitoring claims pled herein. To the extent a class action “ ‘ “eliminates the possibility of repetitious litigation” ’ ” of common issues (Linder, supra, 23 Cal.4th at p. 435), it also eliminates the possibility of inconsistency in their adjudication.
Not only is the nature of plaintiffs’ claims well suited for class treatment, but also the remedy requested here is one that is most effectively administered to a class of plaintiffs. If plaintiffs receive the medical monitoring remedy as a class, one unitary monitoring program with clear standards and procedures can be established. An initial screening can be utilized to detect any preexisting conditions, and to identify any specific risk factors. Diseases may be easier to identify through class treatment of medical monitoring plaintiffs as well, because doctors monitoring a class of plaintiffs exposed to the same toxic chemicals may see similar symptoms in a number of individuals.
In addition, the maintenance of a class action for medical monitoring damages serves as a deterrent for corporate polluters. “Absent a class suit, a wrongdoing defendant [may] retain the benefit of its wrongs.” (Vasquez, supra, 4 Cal.3d at p. 810.) “‘Allowing plaintiffs to recover the cost [of medical monitoring] deters irresponsible discharge of toxic chemicals by defendants.’ ” (Metro-North Commuter R. Co. v. Buckley (1997) 521 U.S. 424, 451 [117 S.Ct. 2113, 2127, 138 L.Ed.2d 560] (conc. & dis. opn. of Ginsburg, J.).) Since the cost of litigating cases on an individual basis may be prohibitive, a class action may be the only way to establish defendants’ liability for the cost of medical monitoring. In fact, unless defendants are held liable for the cost of medical monitoring, they may escape liability altogether. As one court has noted, “The difficulty of proving causation, where the disease is manifested years after exposure, has caused many commentators to suggest that tort law has no capacity to deter polluters, because the costs of proper disposal are often viewed by polluters as *1132exceeding the risk of tort liability. [Citations.] However, permitting recovery for reasonable pre-symptom, medical-surveillance expenses subjects polluters to significant liability when proof of the causal connection between the tortious conduct and the plaintiffs’ exposure to chemicals is likely to be most readily available.” (Ayers v. Jackson Tp. (1987) 106 N.J. 557, 604 [525 A.2d 287, 311-312, 76 A.L.R.4th 571].)
Thus, while “ ‘ [a]ny valid pertinent reason stated [would] be sufficient to uphold the [certification] order’ ” (Linder, supra, 23 Cal.4th at p. 436), the trial court’s certification order in this case is supportable on several grounds: responsible public health policy, efficiency in the expenditure of judicial resources, uniformity of adjudication, effective administration of the remedy, and deterrence of wrongdoing by potential polluters.
V.
Part I of the lead opinion states that medical monitoring claims may be treated as a class “so long as any individual issues the claims present are manageable.” (Lead opn., ante, atpp. 1105-1106.) In reviewing the evidence to be proven at trial, it is clear that the trial court was well within its discretion in concluding that any individual issues in this case are manageable. The majority errs in reweighing the balance of common versus individual issues in this case and determining that common issues do not predominate. This is a conclusion we need not reach. Instead, the weighing of individual versus common factors and the decision on the manageability of the class is an exercise left to the sound discretion of the trial court. A trial court’s class certification determination is discretionary because “ ‘it is “a practical problem, and primarily a factual one with which a [trial] court generally has a greater familiarity and expertise than does a court of appeal[].” ’ ” (Boughton v. Cotter Corp. (10th Cir. 1995) 65 F.3d 823, 828.)
The majority essentially disregards the trial court’s conclusion that the individual issues in this case are manageable and that common issues predominate. Rather than reviewing the certification order for abuse of discretion, the majority rejects plaintiffs’ theory of liability after a merit-based analysis of plaintiffs’ claims. Our role as a reviewing court, however, is not to determine whether or not we agree with the trial court’s conclusion that common issues predominate but only to see whether this conclusion was an abuse of discretion. Unless this decision was an abuse of discretion, it should be upheld.
Plaintiffs allege that they were injured as a class by defendants. They ask that defendants be held responsible for the cost of medical monitoring, *1133which can detect, and prevent, future illness. The trial court determined that class treatment of plaintiffs’ claims was the superior method of dealing with the common questions of law and fact that exist in this case. Substantial evidence supports this determination, and so I conclude that the trial court did not abuse its discretion in certifying the class in this case. Therefore, I dissent.
George, C. J., concurred.

 I note, however, that the record does contain evidence to support plaintiffs’ theory of liability. Plaintiffs’ expert, Dr. Teitlebaum, opined that “even small doses of environmental carcinogens . . . such as those present in Redlands, [and] their breakdown products delivered to the population, are quite capable of interacting with the human genome to produce malignant outcomes.” Dr. Teitlebaum further stated that “any person who fulfills the class definition proposed in this case is at greater risk of developing cancer and other serious illness which is known by scientists and toxicologists to be associated with the chemicals at issue in this case.”

Boggs, supra, 141 F.R.D. 58, involved claims by neighbors of an industrial facility that hazardous materials released from the facility had contaminated their properties. In certifying a medical monitoring class, the federal district court “rejected defendants’ view of the individualized nature of the plaintiffs’ claims” (id. at p. 67), which parallels defendants’ arguments here (see id. at pp. 64-65). The court noted that “[cjommon issues of liability, causation, and remedies not only predominate but overwhelm individualized issues. If these claims were tried separately, the amount of repetition would be manifestly unjustified.” (Id. at p. 67.)