Full Opinion

FIFTH DIVISION BROWN, C. J., MERCIER, P. J., and EPPS, J. NOTICE: Motions for reconsideration must be received no later than 4:30 pm on the 10th day after the decision was issued to be deemed timely filed. https://www.gaappeals.gov/rules November 3, 2026 In the Court of Appeals of Georgia A26A0973. GEORGIA POWER COMPANY v. SINYARD et al. BROWN, Chief Judge. Georgia Power Company appeals from the trial court’s order dismissing Ford Motor Company and Union Carbide Corporation as defendants and ruling that Georgia Power, as the only remaining defendant, is not entitled to have the jury apportion fault among other potential tortfeasors in this asbestos-mesothelioma case. Georgia Power also appeals from the denial of its motion to exclude expert testimony and the denial of its renewed motion for summary judgment. For the reasons that follow, we affirm. This Court reviews “de novo a grant or denial of summary judgment, viewing the evidence and all reasonable conclusions and inferences drawn from it in the light most favorable to the nonmovant.” Henry v. Griffin Chrysler Dodge Jeep Ram, 362 Ga. App. 459, 460 (868 SE2d 827) (2022). Summary judgment is proper when there is no genuine issue of material fact and the movant is entitled to judgment as a matter of law. The burden on the moving party may be discharged by pointing out by reference to the affidavits, depositions and other documents in the record that there is an absence of evidence to support the nonmoving party’s case. If the movant meets this burden, the nonmovant cannot rest on [its] pleadings, but rather must point to specific evidence giving rise to a triable issue. Id. at 460–61 (citations and punctuation omitted). See OCGA § 9-11-56(c), (e). This case is now before this Court for a third time. The pertinent facts, as outlined in Sinyard v. Ga. Power Co., 363 Ga. App. 195 (871 SE2d 45) (2022) (“Sinyard I”), are as follows. Kevin Sinyard was a pipefitter for more than 25 years and worked for more than 41 contractors, including Georgia Power Company, at various job sites across Georgia. Id. at 195–96. Sinyard performed work as an independent contractor for four Georgia Power plants—Scherer, Branch, McDonough and Vogtle—between 1979 and 1986. Sinyard was never directly employed by Georgia Power, and his work was not continuous during this time; instead, he would 2 work for four to six weeks when needed, which was approximately once a year. ... A representative for Georgia Power testified that Georgia Power has used asbestos gaskets, asbestos packing, and asbestos insulation in its plants since the 1930s and continued to stock asbestos products as late as 1992. The representative agreed that asbestos-containing materials existed in all of Georgia Power’s plants during the period of Sinyard’s employment. Id. at 197–98(b)(i), (ii). In 2014, Sinyard was diagnosed with malignant pleural mesothelioma. 363 Ga. App. at 195. In 2016, Sinyard and his wife filed a lawsuit against various defendants, including Georgia Power, Ford Motor Company, and Union Carbide Corporation, alleging negligence, premises liability, loss of consortium, and punitive damages, claiming that his disease was caused by exposure to asbestos while working at facilities owned by some of the defendants.1 Id. at 202(e). 1 After settlements and the grant of summary judgment to one defendant, four defendants remained in the case: Georgia Power, Ford, Union Carbide, and Georgia-Pacific LLC. The case was stayed with respect to Sinyard’s claims against Georgia-Pacific in 2017, due to Chapter 11 bankruptcy proceedings. 3 In 2021, the Sinyards appealed from the grant of summary judgment to Ford, Georgia Power, and another defendant on other grounds. Sinyard I, 363 Ga. App. at 195. This Court reversed the grant of summary judgment to Ford and affirmed in part and reversed in part the grant of summary judgment to Georgia Power. Id. at 195, 203–05(1), 211–12(4), 217. On remand from Sinyard I, Georgia Power, Ford, and Union Carbide Corporation (collectively “Defendants”) moved to exclude the testimony of the Sinyards’ causation expert, Dr. Jerrold Abraham, and two other expert witnesses, Christopher DePasquale and Dr. Steven Compton. Defendants also moved for summary judgment on the issue of causation based on the exclusion of Dr. Abraham’s opinions.2 In a single order, the trial court denied the motions to exclude Dr. Abraham’s testimony, concluding, inter alia, that Dr. Abraham properly based his causation opinions on “reliable ranges of exposure” established by DePasquale and Dr. Compton. The trial court separately denied the motions to exclude testimony of DePasquale and Dr. Compton. Thereafter, the trial court concluded that, given its ruling on the admissibility of Dr. Abraham’s opinions, disputed issues of material fact 2 Georgia Power contended it was entitled to summary judgment on other grounds, which the trial court ultimately rejected. 4 remain as to causation and thus denied the motions for summary judgment. The court certified its orders for immediate review, and we granted Defendants’ applications for interlocutory appeal but later dismissed the resulting appeals as having been improvidently granted Following remittitur to the trial court, the Sinyards participated in mediation with Georgia Power, Ford, and Union Carbide. As a result of that mediation, the Sinyards settled their claims against Ford and Union Carbide, but their claims against Georgia Power remained pending. Ford, Union Carbide, and the Sinyards filed joint motions to dismiss Ford and Union Carbide and drop them as parties to the action in light of the settlements, with the result that Georgia Power would be the sole remaining defendant in the case. Georgia Power objected, asking the court to maintain the status of Ford and Union Carbide as nominal parties because dismissing them “could adversely affect substantial rights of Georgia Power to apportionment of fault and damages under OCGA § 51-12-33,” or, alternatively, to apply the newly enacted provisions of OCGA § 51-12-15. The trial court granted the motions, dismissed Ford and Union Carbide, and ruled that Georgia Power is not entitled to apportionment of fault. Specifically, the trial court ruled that OCGA § 51-12-15 divides personal injury 5 trials into three procedural phases and grants a defendant a right, in the first phase, to introduce evidence that other defendants and non-parties may be at fault. The trial court determined, however, that the statute creates a new substantive right, so it cannot be applied retroactively. At the request of Georgia Power, the trial court certified its order for immediate review, and this Court subsequently granted Georgia Power’s application for interlocutory review. Georgia Power appeals from this order and also enumerates as error the trial court’s previous denial of its motions to exclude the testimony of the Sinyards’ expert witnesses and the denial of its renewed motion for summary judgment.3 1. At the time the Sinyards filed their complaint, OCGA § 51-12-33(b) (2005) provided for the apportionment of fault when a lawsuit involved multiple defendants: Where an action is brought against more than one person for injury to person or property, the trier of fact, in its determination of the total amount of damages to be awarded, if any, shall . . . apportion its award of damages among the persons who are liable according to the percentage of fault of 3 Because we have jurisdiction to address the trial court’s order dismissing Union Carbide and Ford under OCGA § 5-6-34(b), we also have jurisdiction to address the orders denying Georgia Power’s motion to exclude Dr. Abraham’s testimony and its renewed motion for summary judgment under OCGA § 5-6-34(d). See Gulfstream Aerospace Servs. Corp. v. U.S. Aviation Underwriters, Inc., 280 Ga. App. 747, 751 n.5 (635 SE2d 38) (2006); Aetna Cas. & Surety Co. v. Cantrell, 197 Ga. App. 672, 672–73(1) (399 SE2d 237) (1990). 6 each person. Damages apportioned by the trier of fact as provided in this Code section shall be the liability of each person against whom they are awarded, shall not be a joint liability among the persons liable, and shall not be subject to any right of contribution. (Emphasis supplied.) In AU Medical Center v. Dale, 373 Ga. App. 521 (908 SE2d 790) (2024), this Court interpreted the phrase “[w]here an action is brought against more than one person” to mean that apportionment is available only when more than one defendant remains in the case at trial. Id. at 530–32(1)(c). In other words, where—as here—all defendants except one have been dismissed before trial, then the trier of fact will not apportion fault under OCGA § 51-12-33(b). Georgia Power acknowledges that as a result of the trial court’s dismissal order and our AU Medical Center decision, it is not entitled to apportionment under OCGA § 15-12-33(b).4 Nonetheless, Georgia Power maintains that it is entitled to apportion fault under a different statute, OCGA § 51-12-15(a), which became effective as part of Georgia’s Tort Reform Act on April 21, 2025, and provides as follows: 4 In a footnote, Georgia Power summarily argues that AU Medical Center was “wrongly decided as argued by the dissent and this Court should overrule it.” We decline. 7 (a) In any action to recover damages for bodily injury or wrongful death, any party may elect ... to have fault and any award of damages determined at trial in the following manner: (1) In the first phase of the trial, the trier of fact shall determine the fault of each defendant, and if the trier of fact finds that any defendant is at fault for the plaintiff’s injuries or wrongful death, the trier of fact shall further determine through an appropriate form of the verdict the percentage of fault of all persons or entities that contributed to such injuries or wrongful death as provided in Code Section 51-12-33, prior to any determination of the total amount of damages to be awarded[.]... (2) If the trier of fact finds in the first phase of the trial that any defendant is at fault for the plaintiff’s injuries or wrongful death, the trial shall be recommenced immediately with the same judge and the same jury. In the second phase of the trial, the trier of fact shall determine all compensatory damages to be awarded to the plaintiff, if any, and the evidence and arguments of counsel shall be limited to this issue; and (3) If the trier of fact finds in the second phase of the trial that any compensatory damages are to be awarded to the plaintiff, the trial may be recommenced immediately with the same judge and the same jury for such further proceedings as may be required, including, but not limited to, proceedings provided for in subsection (d) of Code Section 51-12-5.1 concerning punitive damages and proceedings to determine liability for, and the amount of, any attorney’s fees, court costs, or expenses of litigation that may be awarded by the trier of fact as provided by law. 8 (Emphasis added.) Georgia Power asserts that the apportionment provisions of OCGA § 51-12-15 retrospectively apply in this case. As stated above, the trial court concluded that the statute creates a new substantive right and thus could not apply retroactively. “As the standard of review for a question of law on appeal is de novo,” we review the trial court’s ruling de novo. Advantage Behav. Health Sys. v. Cleveland, 350 Ga. App. 511, 517(2) (829 SE2d 763) (2019) (punctuation omitted). “The presumption against retroactive legislation is deeply rooted in our jurisprudence, and embodies a legal doctrine older than our Republic. For that reason, courts usually insist upon some clear indication in the statutory text that a statute is to be applied retroactively before so applying it.” Howard v. Coffee Regional Med. Ctr., Inc., 377 Ga. App. 742, 748(2) (922 SE2d 890) (2025). Here, the legislature provided such a “clear indication” in the amendment enacting Georgia’s 2025 Tort Reform Act: Sections 6 and 7 of this Act shall apply only with respect to causes of action arising on or after the effective date of this Act, and any prior causes of action shall be governed by prior law. It is the intention of the General Assembly that all other provisions of this Act shall apply to causes of action pending on the effective date of this Act, unless such application would be unconstitutional. 9 Ga. L. 2025, p.9 §9(b) (emphasis added). The Code section at issue is found in Subsection 8 and thus should be given retroactive effect unless our Constitution forbids it. See Deal v. Coleman, 294 Ga. 170, 174–75(1)(b) (751 SE2d 337) (2013). See also Southern States Chem., Inc. v. Tampa Tank & Welding, Inc., 316 Ga. 701, 708(1) (888 SE2d 553) (2023) (“It is only when such a clear indication is present that we then consider whether retroactive application is unconstitutional[.]”). Accordingly, we must determine whether the retroactive application of OCGA § 51-12-15(a) is unconstitutional. “The prohibition in Art. I, Sec. I, Par. X of the Georgia Constitution of 1983 against retroactive laws applies only to those laws which affect or impair substantive rights under prior law which have vested at the time the subsequent law takes effect.” Devore v. Liberty Mut. Ins. Co., 257 Ga. App. 7, 9 (570 SE2d 87) (2002). “That is, retrospective operation takes away or impairs vested rights acquired under existing laws or creates a new obligation, imposes a new duty, or attaches a new liability in respect to transactions or considerations already past.” Fowler Props., Inc. v. Dowland, 282 Ga. 76, 77–78(1) (646 SE2d 197) (2007) (punctuation omitted). “Where an amendment to a statute changes procedure or rules of evidence, it does not affect or 10 impair vested substantive rights, and it is to be given retroactive effect absent the legislature’s expressed contrary intention.” Devore, 257 Ga. App. at 9. See also Murphy v. Murphy, 295 Ga. 376, 377 (761 SE2d 53) (2014) (“[O]ne has no vested rights in any course of procedure, and the presumption against a retrospective statutory construction does not apply to statutory enactments which affect only court procedure and practice, even when the alteration from the statutory change results in a disadvantage to a party.”); DaimlerChrysler Corp. v. Ferrante, 281 Ga. 273, 274(1) (637 SE2d 659) (2006) (“Procedural law is that law which prescribes the methods of enforcement of rights, duties, and obligations.” (punctuation omitted)). Examples of laws found by Georgia appellate courts to affect only procedure or remedy include the following: provisions of the Tort Reform Act of 2005 governing the qualification of expert witnesses and the admissibility of expert testimony in civil cases;5 a statute making an award of interest automatic in child support proceedings when requested by the person owed child support;6 a statutory amendment requiring 5 Mason v. Home Depot U.S.A., Inc., 283 Ga. 271, 278–79(4) (658 SE2d 603) (2008) (provisions, as evidentiary rules, were procedural and thus application of the statute to plaintiffs’ case did not violate the constitutional prohibition against retroactive laws). 6 Reid v. Reid, 232 Ga. App. 304, 306 (502 SE2d 269) (1998) (concluding that statute at issue was “procedural or remedial” in nature, rather than substantive, because it “in no 11 those desiring to file suit for damages against a municipality to include certain specific information in the required ante litem notice, namely “‘the specific amount of monetary damages being sought[.]’”7 Conversely, the following were found to affect substantive rights: a statute extinguishing the right to a jury trial in a paternity suit;8 provisions of the asbestos claims statute requiring plaintiffs to produce prima facie evidence establishing that exposure to asbestos was a substantial contributing factor to their medical conditions;9 a law imposing an additional duty and obligation to pay an opposing party’s attorney fees following a rejected settlement offer when a final judgment does not meet a way alters a person’s obligation to pay child support ... [but] only alters the manner in which an obligee owed child support can proceed to obtain interest ... on the unpaid child support payments”). 7 Harrell v. City of Griffin, 346 Ga. App. 635, 640(2)(b) (816 SE2d 738) (2018) (amendment to OCGA § 36-33-5 “merely refine[d] one aspect of the procedure for enforcing the rights [plaintiff] had arising out of her tort cause of action” and thus could be retrospectively applied). 8 Hargis v. Dep’t of Human Res., 272 Ga. 617, 617–18 (533 SE2d 712) (2000) (The right to a jury trial is a substantive one, and thus the statute extinguishing the right to a jury trial in a paternity suit could not be applied retrospectively.). 9 Daimler Chrysler Corp. v. Ferrante, 281 Ga. 273, 274(1) (637 SE2d 659) (2006) (provisions affected plaintiffs’ substantive rights by imposing a greater evidentiary burden than was required under the law in effect at the time their actions were filed and could not retroactively be applied to their claims). 12 certain amount or is one of no liability;10 a statute repealing the cause of action for alienation of affections;11 and a statute abolishing the rule that a plaintiff could not recover against a tortfeasor damages for which minimum, mandatory no-fault compensation was available.12 Additionally, in F. H. Ross & Co. v. White, 224 Ga. 324 (161 SE2d 857) (1968), the Georgia Supreme Court held that the “[t]he right of contribution between joint trespassers is a substantive right,” and thus the statute creating such a right could not be applied retrospectively. Id. at 325(2). The distinctions drawn by these cases support the conclusion that the right of apportionment is a substantive right affecting a defendant’s liability and a plaintiff’s ability to collect. In considering whether apportionment is procedural or substantive in nature, we also find it instructive that other state courts considering the issue have concluded that similar statutes are substantive for retroactivity purposes. See, e.g., CNA Ins. Co. v. Ellis, 148 P.3d 874, 878(I)(A) (Okla. 2006) (holding change of law from 10 Fowler Props., Inc., 282 Ga. at 78(1). 11 Enger v. Erwin, 245 Ga. 753, 754–55 (267 SE2d 25) (1980). 12 Glover v. Colbert, 210 Ga. App. 666, 669 (437 SE2d 363) (1993). 13 apportionment of liability to sole liability of current insurer affected substantive rights of parties and could not be given retroactive effect); Forsythe v. Valley Consol. Indus., 139 MichApp 211, 217 (361 NW2d 768) (1984) (statutory amendment that took away the right of the most recent employer to have its liability for compensation apportioned among prior employers in proportion to the time that the employee was employed in the service of each prior employer affected substantive rights and thus could only apply prospectively); Aucoin v. State of Louisiana Through Dep’t of Transp. & Dev., 712 So.2d 62, 67 (La. 1998) (where statutory amendment shifting to joint and several obligation from solidary liability “altered the existing rule” and resulted in changing the amount of damages recoverable, the change was clearly substantive and, as such, the amendment could have only prospective application).13 Cf. Roth v. Roth, 571 SW2d 659, 672 (Mo. Ct. App. 1978) (Missouri Supreme Court ruling affecting apportionment of damages and the rights of recovery among joint tortfeasors was a change in substantive law and thus applied prospectively). Cf. Keith v. U.S. Fid. & Guar. Co., 694 So. 2d 180, 183 (La. 1997) (revision to apportionment statute affecting “the quantification of employer fault” was procedural; the substantive right to 13 Aucoin was subsequently overturned by legislation. 14 allocate fault was created previously with the introduction of comparative fault and revision at issue “simply delineates a method for enforcing that substantive right”). In contending that the apportionment provisions of OCGA § 51-12-15 are procedural in nature, Georgia Power asserts that OCGA § 51-12-15 “did not create Georgia’s apportionment scheme, which was added to the law in 2005, and changes absolutely nothing about how fault is actually distributed.” Rather, it “changes the timing for when fault determinations are made and requires apportionment in a trifurcated trial.” Further, according to Georgia Power, “OCGA § 51-12-15 does not impair any party’s or non-party’s vested substantive rights” and “should be read in pari materia with its pre-existing and unaltered sister apportionment statute, OCGA § 51-12-33 (2005) and (2022).” (Punctuation omitted.) We agree with the assertion that OCGA § 51-12-15 is a procedural vehicle for the apportionment statute, OCGA § 51-12-33. See Transcontinental Carriers, Inc. v. Bennett, __ Ga. App. __(1) (__SE2d __) (2026), A26A1643, slip op. at 3(1) (Ga. Ct. App. Sept. 9, 2026) (2026 WL 2653790). Despite arguing that OCGA § 51-12-15 does not create or alter any substantive rights and is simply a procedural statute, Georgia Power nonetheless contends that OCGA § 51-12-15 “is the most recent expression of the General 15 Assembly on ... the availability of apportionment,” and thus it controls over OCGA § 51-12-33. As already explained, the prior version of OCGA § 51-12-33 applies to this case, and under this Court’s binding precedent, Georgia Power is not entitled to apportion fault under OCGA § 51-12-33(b) (2005).14 See AU Medical Center, 373 Ga. App. at 532(1)(c). To the extent OCGA § 51-12-15 alters whether Georgia Power is entitled to apportionment, as Georgia Power argues, it is not merely “enforc[ing] existing obligations, or confirm[ing] existing rights.” Fowler Props., Inc., 282 Ga. at 78(1). Rather, it alters substantive rights, and as such, retrospective application of OCGA § 51-12-15 to this case does not comport with the Georgia Constitution. See White, 224 Ga. at 325(2). 2. Georgia Power contends that the trial court erred in denying its motion to exclude the specific causation testimony of Dr. Jerrold Abraham, the Sinyards’ expert, under Scapa Dryer Fabrics v. Knight, 299 Ga. 286 (788 SE2d 421) (2016). It also contends that DePasquale’s and Compton’s opinions are inadmissible as unreliable. 14 The 2022 revision to the statute is not retroactive and only applies to cases filed after May 13, 2022. See Ga. L. 2022, p. 802, §§ 2-3. See, e.g., Southern Oil Refinery, LLC v. Price, 372 Ga. App. 427, 428(1) n.2 (903 SE2d 693) (2024), disapproved on other grounds, AU Med. Ctr., 373 Ga. App. at 521. The Sinyards filed suit in 2016. 16 Admissibility of Expert Testimony “OCGA § 24-7-702 (“Rule 702”) governs the admissibility of expert testimony and requires that the trial court act as gatekeeper to ensure the relevance and reliability of expert testimony.” Kershaw v. Princeton Properties Mgmt., 348 Ga. App. 779, 782 (824 SE2d 668) (2019) (physical precedent only) (punctuation omitted). Under Rule 702, the trial court has broad discretion to admit or exclude expert testimony. Miller v. Golden Peanut Co., 317 Ga. 22, 30(2) (891 SE2d 776) (2023). See also Smith v. CSX Transp., 343 Ga. App. 508, 510(1) (806 SE2d 890) (2017) (“the determination of whether a witness is qualified to render an opinion as an expert is a legal determination for the trial court and will not be disturbed absent a manifest abuse of discretion”) (punctuation omitted). “The proffering party bears the burden of presenting evidence of reliability in order to meet the standards of [Rule 702].” Hart v. Phung, 364 Ga. App. 399, 406(1) (876 SE2d 1) (2022) (punctuation omitted). Rule 702 provides: A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise, if: (1) The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; 17 (2) The testimony is based upon sufficient facts or data; (3) The testimony is the product of reliable principles and methods; and (4) The expert has reliably applied the principles and methods to the facts of the case. OCGA § 24-7-702(b). Causation “Causation is an essential element of a toxic tort case.” Butler v. Union Carbide Corp., 310 Ga. App. 21, 30(2) (712 SE2d 537) (2011). In such a case, “the plaintiff must prove both general causation, that a substance is capable of causing a particular injury or condition, and specific causation, that a substance made a meaningful contribution to a particular individual’s injury.” Wadley v. Mother Murphy’s Laboratories, 357 Ga. App. 259, 263(1) (850 SE2d 490) (2020) (punctuation omitted). Specific causation is at issue in these appeals. “Where, as here, the case involves a ‘specialized medical’ question, expert testimony is required to establish causation.” Kershaw, 348 Ga. App. at 782. See also Butler, 310 Ga. App. at 30(2). Thus, “[a]bsent reliable expert testimony that exposure to [asbestos in a Georgia Power facility] contributed to the development of [Sinyard’s] mesothelioma, there is insufficient evidence to create a jury issue as to causation.” 18 Butler, 310 Ga. App. at 30(2). More specifically, to prove causation in an asbestos- mesothelioma case, a plaintiff must “show that exposure to asbestos [at the premises or in the products in question] was a contributing factor in bringing about his mesothelioma.” Scapa, 299 Ga. at 290 (punctuation omitted). While the contribution to the resulting injury need not be “substantial,” to show legal causation, a “de minimis” contribution is not enough. Id. Thus, a plaintiff must show that the exposure to asbestos by the defendant “made a meaningful contribution” to his mesothelioma. In Scapa, our Supreme Court held that the trial court abused its discretion in admitting the testimony of Dr. Jerrold Abraham—Sinyard’s expert at issue here—because his testimony did not fit the legal standard for causation in a toxic tort case. In that case, the plaintiff sued a textile manufacturer claiming that it negligently exposed him to asbestos while he worked at one of its facilities and thereby caused his mesothelioma. 299 Ga. at 286–87. Dr. Abraham opined that, “if [the plaintiff] actually was exposed to asbestos while working at the [manufacturer’s] facility, that exposure was a cause of his mesothelioma, regardless of the precise extent of the exposure.” Id. at 287. Dr. Abraham reasoned that “[b]ecause each and every exposure to respirable 19 asbestos in excess of the background contributes to the cumulative exposure, ... each exposure in excess of the background is a contributing cause of the resulting mesothelioma, regardless of the extent of each exposure.” Id. at 288. The manufacturer appealed the jury’s verdict against it, contending that the trial court erred in admitting Dr. Abraham’s testimony because his theory of cumulative exposure was not reliable and did not comport with the legal requirements for causation. Id. The Supreme Court agreed with the latter argument, explaining: By his testimony, Dr. Abraham essentially told the jury that it was unnecessary to resolve the extent of exposure at [the manufacturer’s] facility—if the jury determined that [the plaintiff] was exposed at the facility to any asbestos beyond background, that exposure contributed to his cumulative exposure, and according to Dr. Abraham, it was, therefore, a contributing cause of the mesothelioma. 299 Ga. at 291. The Court qualified its holding by clarifying that expert testimony premised upon a cumulative exposure theory could be relevant to causation under Georgia law if “coupled ... with reliable data sufficient to show that the exposure in question were more than de minimis[.]” Id. at 291–92. More specifically, and pertinent to the instant case, 20 if an expert coupled his reliance on the cumulative exposure theory with reliable data sufficient to show that the exposure in question were more than de minimis—and if the expert qualified his ultimate opinion as to causation, conditioning it upon there having been more than a de minimis exposure—the opinion then might “fit” the pertinent causation inquiry, notwithstanding that the extent of exposure is disputed. In that instance, the jury would have to resolve the extent of the exposure, and if the jury accepted that the exposure was as significant as the data of the expert suggested, it then could accept his opinion as to causation. Id. at 291–92. Admissibility of Christopher DePasquale’s Testimony (a) DePasquale’s Opinions. Christopher DePasquale is a certified industrial hygienist, an asbestos inspector, and asbestos management planner and has conducted industrial hygiene, asbestos management, and indoor air quality studies. DePasquale’s opinion reviews various industrial hygiene studies regarding asbestos and how those studies apply to Sinyard’s asbestos exposure. According to DePasquale, he was retained in order to prepare a report summarizing Sinyard’s exposures to asbestos based on his review of various materials and documents provided to him by Sinyard’s 21 counsel, including a review of Sinyard’s depositions.15 DePasquale provided “ranges of exposures as it relates to certain work practices” nonspecific to any particular premises or defendant. When asked to describe his method for arriving at the exposure ranges, DePasquale elaborated: I’ve tried to gain an understanding of Mr. Sinyard’s career, his opportunities to be exposed to asbestos. I’ve attempted to review the literature, both published and unpublished, as it relates to exposures relevant to Mr. Sinyard’s career, trying to identify similar exposure groups, and then applying that data to Mr. Sinyard. In most instances, DePasquale took “descriptions of similar work that Mr. Sinyard did that is reported in the literature ... basically summarizing that reported literature and giving a range of exposures based on that literature.”16 DePasquale offered ranges of exposure because “that’s the appropriate way ... based on the existing literature, and certainly with the acknowledgment that there may be variations, for example, in environmental conditions, methodologies with regard to how Mr. Sinyard may have 15 In reviewing Sinyard’s depositions, DePasquale “was attempting to gain an understanding of Mr. Sinyard’s occupational, nonoccupational, [and] potential take-home exposures relating to asbestos over the course of his lifetime[.]” 16 “Range” specifically refers to a range of asbestos fibers and is measured in a “fiber per CC measurement.” 22 done the work.” Based on these ranges, it was DePasquale’s opinion that the tasks/exposures would have increased Sinyard’s risk for the development of mesothelioma. (b) Analysis. Georgia Power contends that DePasquale’s “fictional ranges of exposure” are “divorced from any specific facts of Sinyard’s case.” A review of DePasquale’s report and testimony flatly contradicts this. And, Georgia Power’s argument that DePasquale’s opinion must be entirely excluded because he failed to consider every possible variable in estimating every range of exposure is without merit. “An expert has great liberty in determining the basis of his opinions. As a general rule, the factual basis of an expert opinion goes to the credibility of the testimony, not the admissibility, and it is up to the opposing party to examine the factual basis for the opinion in cross-examination.” Emory Univ. v. Willcox, 355 Ga. App. 542, 545(2) (844 SE2d 889) (2020) (citations and punctuation omitted). Here, “De[P]asquale has used data as close as possible based on the information available, a technique that other courts ... have endorsed for exposure reconstruction assessments.” Michel v. Ford Motor Co., No. CV 18-4738, 2019 WL 118008, at *8(III) (E.D. La. Jan. 7, 2019) (rejecting similar arguments attacking the reliability and factual basis of DePasquale’s 23 opinions in an asbestos-mesothelioma case). Such issues can be fully explored on cross-examination. See Old Republic Nat. Title Ins. Co. v. RM Kids, LLC, 337 Ga. App. 638, 646–47(4) (788 SE2d 542) (2016) (affirming trial court’s order denying motion to exclude expert testimony allegedly not based on reliable data or recognized methodology where the expert was properly qualified and the facts relied upon were within the bounds of evidence; questions about whether there was sufficient knowledge upon which to base an opinion went to the weight and credibility of the testimony, not its admissibility). To the extent Georgia Power contends that DePasquale’s opinions should be excluded because his ranges of exposure are untethered from the alleged exposures at specific premises, this argument is likewise without merit. DePasquale estimated “ranges of exposures as it relates to certain work practices,” which Sinyard would have performed as a pipefitter at sites owned by both Ford and Georgia Power. It is unclear, and Georgia Power does not elucidate, how this renders DePasquale’s methodology unreliable or shows that he failed to apply his methodology reliably to the facts of the case. See OCGA § 24-7-702(b). “The trial court’s broad discretion afforded [it] considerable leeway in deciding how to assess the reliability of 24 [DePasquale’s] opinion.” Emory Univ., 355 Ga. App. at 544–45(2). The trial court did not abuse its “broad discretion” in denying the motion to exclude DePasquale’s opinion evidence. Admissibility of Dr. Compton’s Testimony (a) Dr. Compton’s Opinions. Dr. Compton is a microscopist and physicist. According to his testimony, he reviewed an extensive amount of materials related to this case, including Sinyard’s testimony. It was Dr. Compton’s opinion that many of the tasks Sinyard described performing as a pipefitter, as well as the tasks described involving the drywall mix product, would have released asbestos fibers into the air, and further that “the concentrations that have been reported in studies evaluating those types of activities report airborne fiber concentrations that are, generally speaking, orders of magnitude above ambient levels that were reported by the Agency for Toxic Substances and Disease Registry.”17 Dr. Compton was prepared to offer ranges of exposure to asbestos fibers based on each of the activities or products Sinyard described. His opinions related to the exposures for specific activities but did 17 According to Dr. Compton, the Agency for Toxic Substances and Disease Registry publishes results which “describe average [ambient asbestos] concentrations from both rural and urban areas across the U. S.” 25 not calculate cumulative asbestos exposure or dose at any particular work site. He did not examine the specific gaskets, packing materials, or products handled by Sinyard nor did he visit the specific sites where Sinyard worked. Dr. Compton clarified that he was “relying on prior testing that I’ve performed on those types of materials, as well as the facts of the case; whether it’s testimony of the witnesses or any of the supporting documents,” including corporate records disclosed by Georgia Power. Dr. Compton previously had performed tests “that would be relevant to what [Sinyard] described, but nothing that was designed specifically to evaluate anything he did as opposed to any other individual who was performing that kind of work.” He had personally studied and/or tested gaskets and insulating materials. In reaching his conclusions, Dr. Compton also relied on various studies and research. (b) Analysis. Georgia Power asserts that Dr. Compton’s “opinions rely entirely on studies and simulations conducted in a laboratory for litigation purposes” and “do not reliably apply any scientific principles and methods to the facts of the case.”(Punctuation omitted.) Georgia Power also takes issue with the fact that none of the studies Dr. Compton relies on “were conducted specifically for Sinyard’s case or under the conditions and circumstances experienced by Sinyard,” and that he had 26 not visited any of Sinyard’s work sites, performed air sampling at the work sites, or tested the specific products used by Sinyard. As explained above in reference to DePasquale’s testimony, “the factual basis of an expert opinion goes to the credibility of the testimony, not the admissibility, and it is up to the opposing party to examine the factual basis for the opinion in cross-examination.” Emory Univ., 355 Ga. App. at 545(2) (punctuation omitted). See also Ovation Condo. Assn. v. Cox, 374 Ga. App. 681, 694(1)(c)(ii) (913 SE2d 819) (2025) (plaintiff’s expert in industrial hygiene “need not have personally visited [the plaintiff’s] unit or personally inspected the generator to have a sufficient factual basis for his opinion”). Additionally, such arguments regarding the reliability of Dr. Compton’s methodologies have been rejected by other courts. See, e.g., Young v. John Crane, Inc., No. CV 21-4