Y o u n g L a w y e r s Challenging Plaintiff’s Expert Defending Lead- Containing Toy

By Ryan L. Nilsen Lawsuits and Michael R. Carey

Think creatively An injured child epitomizes the sympathetic plain- and exploit as many tiff. Not surprisingly, therefore, children injured by toys weaknesses as possible. containing lead have captured the attention of the plain- tiffs’ bar. Proving—or disproving—exposure, causa- tion, and damages in cases, tion (CDC), the mean level of lead in chil- however, is not child’s play. dren ages one to five was 2.2 µg/dl in 2000. This article will explore ways to chal- Any level higher than 10 μg/dL, the CDC lenge plaintiffs’ experts in lead toy expo- notes, is cause for concern. sure litigation by highlighting common Lead has no known biological role in the weaknesses in exposure analysis, cogni- body. Its results from its ability to tive-injury proof, and specific causation. mimic other biologically important metals, such as calcium, iron, and zinc, that bind Lead Is Everywhere to proteins and molecules throughout the Lead is everywhere in our environment. body. Once bound to lead, these proteins Its most prevalent source is leaded-fuel and molecules can no longer carry out the exhaust that, for decades, has accumu- same reactions, such as producing enzymes lated in the soil and entered our bodies as necessary to certain biological processes. dust. Exposure also occurs in residential For centuries, lead exposure has been homes when lead paint peels and flakes associated with negative health effects, off walls and children ingest the chips or including irreversible neurological dam- when drinking water becomes contam- age, renal disease, cardiovascular effects, inated by lead piping and solder used in and reproductive toxicity. According to home plumbing. modern scientists, famed composer Lud- Because lead is so prevalent in the envi- wig van Beethoven died of lead poisoning. ronment, nearly everyone has a measur- Among United States toy manufacturers, able blood-lead level (BLL). According to lead content is regulated by the Consumer the Centers for Disease Control and Preven- Product Safety Commission (CPSC). CPSC

n Ryan L. Nilsen is a partner and Michael R. Carey is an associate in the Minneapolis office of Bowman and Brooke LLP. Mr. Nilsen’s legal practice focuses on defense, primarily involving chemical exposure, medical device, pharmaceutical, and recreational vehicle cases. He is an active member of DRI’s Young Lawyers Committee and currently serves as vice chair of its Publications Subcommittee. Mr. Carey practices in the areas of products liability, toxic and warranty claims. The authors wish to recognize Wayne Struble for his assistance in editing this article.

© 2008 DRI. All rights reserved. For The Defense n February 2008 n 43 Y o u n g L a w y e r s regulations apply to everything from metal level of lead found in the child’s blood. Lead absorbed into the body, compared to just 20 alloys used in toy jewelry to the paint that absorption is a function of lead’s physio- to 70 percent of ingested lead (with children covers the toys themselves. But CPSC reg- chemical properties, concentration, and generally absorbing higher percentages ulations do not apply to the manufacture commingling with other agents that can than adults). Accordingly, the absorption of toys abroad. Nevertheless, domestic dis- assist or interfere with its intake. “For ex- of lead from a lead painted toy is different tributors and retailers remain liable under ample, inhaled lead is absorbed almost to- from a toy made of lead. state product liability laws for the harmful tally, whereas ingested lead is taken up only effects of foreign-made products that they partially into the body. Iron deficiency and Regulatory Standards Are Not place into the stream of commerce. low nutritional calcium intake, both com- Injury-Causation Thresholds mon conditions of inner-city children, in- The key to understanding the injury- crease the amount of ingested lead that is ­causation thresholds is the relationship absorbed in the gastrointestinal tract and between exposure level and injury risk. As Watch out for the exposure passes into the bloodstream.” B. Goldstein a basic tenet of toxicology, the injury result- and M. Henifin,Reference Guide on Toxicol- ing from a depends on the dose of the expert who concludes ogy, Reference Manual on Scientific toxin received. Related to that tenet is the Evidence (2d ed. 2000) at 424. concept of “threshold dose.” The “thresh- that ingestion occurred In addition to exposure and absorption, old” or “no effect level” is the level of expo- an expert must be prepared to explain the sure below which a substance does not and then sets out to find pathway of exposure from the toy into the exhibit a toxic effect or at least manifest a plaintiff’s body. The primary pathway for clinically observable effect. support for the conclusion. lead poisoning is ingestion. But lead can In 1975, blood-lead levels up to 30 µg/dl also enter the body through skin absorp- were considered safe. In 1985, the thresh- tion and, less frequently, inhalation. An old was lowered to 25 µg/dl. In 1991, the Evidence of Exposures Is expert must account for the method of threshold was lowered again to the present Not Proof of Causation delivery—and based on scientific princi- standard of 10 µg/dl. Various factors affect proof of specific cau- ples, not mere speculation. In this regard, In response to recent concerns over lead sation in lead-exposure cases, including watch out for the exposure expert who con- in imported toys, the CDC has shrugged exposure, absorption, pathway, and cludes that ingestion occurred and then off calls for further reduction of its lead absorption rates. Look for four things to sets out to find support for the conclusion. threshold level because, according to the attack plaintiff’s proof of specific causa- See Mitchell v. Gencorp Inc., 165 F.3d 778, CDC, “any decision to establish a new level tion. The first element of specific causa- 783 (10th Cir. 1999) (recognizing that sci- of concern would be arbitrary and provide tion is actual exposure to lead. In lead, as entists who testify about their conclusions uncertain benefits.” in other toxin cases, exposure is a condi- before performing necessary validation Thus, regulatory standards do not tion precedent to causation. Exposure can tests may lack the objectivity required by provide compelling evidence of injury- be proven in a variety of ways. For exam- the scientific method). ­causation thresholds for litigation. Reg- ple, blood tests can measure suspected lead Proof of the pathway of exposure will, ulatory standards “traditionally include exposure. When elevated levels of lead in in turn, require evidence excluding other protective factors to reasonably ensure that the bloodstream are present, the plaintiff’s sources of lead exposure. Adults most susceptible individuals are not put at risk.” treating physician can testify to the lead often encounter lead at work, while chil- B. Goldstein and M. Henifin, Reference levels found in the plaintiff’s blood and the dren generally encounter lead through play. Guide on Toxicology, Reference Manual symptoms reported. Children generally absorb lead into their on Scientific Evidence (2d Ed. 2000) at But proof of exposure is not enough to bloodstream at a higher rate than adults. 424. The mere fact that an individual has establish specific causation. Proof that a For both adults and children, the main been exposed to a level above a regulatory toy caused lead poisoning also requires ev- sources of lead poisoning are lead-contam- standard does not necessarily mean that an idence that the lead present in the toy is in a inated soil and lead-based paint dust or adverse effect has occurred. form that can be absorbed into the body. For chips, particularly in older houses. Lead- Nevertheless, plaintiff experts use regu- this type of evidence, a plaintiff must offer based paints can disintegrate into powder latory standards to prop up their causation expert testimony, often from a toxicologist. and be inhaled or swallowed, such as when theories. When a child’s BLL exceeds 10 µg/ Be skeptical of a treating doctor, or a pro- teething children suck on painted window- dl, they argue, adverse health effects will fessed exposure expert, who merely testifies sills as they look outside. Lead dust can also follow. Indeed, research conducted since that the toy at issue contains lead and that enter the circulatory system through the 1991 offers some evidence that children’s children generally put toys in their mouths. digestive track faster and more readily than physical and mental development can be That children put toys in their mouths does a solid piece of lead. affected at BLLs below 10 µg/dL. not prove that a toy containing lead can Finally, proof of specific causation But the CDC and EPA’s choice of 10 µg/dL or actually did transfer lead into a child’s requires evidence on lead absorption is based on a significant body of scientific -ev body or in an amount consistent with the rates. Almost 100 percent of inhaled lead is idence showing that several significant health

44 n For The Defense n February 2008 effects occur in the 10–15 µg/dL range. The or twenty years or more may intervene from any particular uses of latex paint EPA emphasizes, however, that its standard between the exposure and the manifes- are high enough to cause any reaction, does not imply that 10 µg/dL is a threshold tation of disease highlights the practical that prolonged, unspecified low level level. On the contrary, EPA maintains that difficulties encountered in the effort to exposure to irritants can cause asthma, there is no known threshold for lead, and that prove causation. or that latex paints generally (or these it chose 10 mg/dL because studies of adverse James v. Bessemer Processing Co., 714 A.2d paints in particular) cause asthma. health effects at lower levels of exposure are 898, 909 (N.J. 1998). Id. at 905. not well substantiated and observed only a Poking holes in specific causation is the limited number of children. defendant’s best chance to defeat a lead Be Wary of the Overreaching Plaintiffs claim that adverse health exposure lawsuit. Specific causation is the Neuropsychologist effects arise at blood-lead levels far below direct connection between two events in Some lead exposure studies have reported the 10 µg/dL regulatory standard, and their which the occurrence of one event is nec- cognitive declines from quantifiable expo- experts rely on the standard to sug- essary to the event that follows. sures. Other researchers and child advo- gest very low-dose exposures cause inju- Epidemiology alone cannot prove spe- cacy groups claim an association between ries in children. Reliance on the hazard cific causation. It can only demonstrate that early lead exposure and extreme learning standard is especially prevalent in lead toy lead is capable of causing certain harms. For disabilities, including speech development cases in which the uptake of lead is diffi- this reason, defense counsel should be on and even autism. Some studies even attri- cult to quantify. guard against any expert who plans to opine bute behavioral problems to lead exposure. If confronted by this claim, defend- on specific causation based solely on the fact Plaintiffs frequently offer the testimony of a ants should emphasize that neither the that lead exposure can cause harm. Also neuropsychologist to prove causation. CDC nor the EPA has lowered its hazard untrustworthy are causation opinions con- Predictably, therefore, plaintiffs may rely standard. Unless and until the CDC or the necting high BLLs to nothing more than a on a neuropsychologist to establish spe- EPA changes their hazard standard, the child’s toy-box full of lead-containing toys, cific causation between lead ingestion and defense bar should attack any expert who without addressing alternative explanation. neuro-cognitive deficiency. More sophis- opines on specific causation based on expo- With so many pathways for exposure, the ticated plaintiffs may proffer a neuropsy- sures below the 10 dl/mg threshold. For expert who concludes that a lead-containing chologist with a specialty in pediatrics. example, a New York court recently relied toy is the source of elevated BLLs is ripe for Defendants should be skeptical of a neu- upon the 10 µg/dl hazard standard to find attack. From the beginning of a case, man- ropsychologist who attempts to link cogni- no negligence in a medical malpractice ufacturer defendants should prepare for a tive deficits to lead exposure based on the case for failing to treat a patient with a BLL full-scale Daubert attack under Federal Rule alleged onset of reduced IQ. Rarely will a of 9 µg/dL. See Breeden v. Valentino, 2007 of Civil Procedure 702. neuropsychologist have conducted an IQ WL 3070774 *2 (N.Y. Sup. 2007). The court Courts require proof of exposure with test before the alleged exposure to use as a noted that, under New York State Pub- varying degrees of specificity. But one thing baseline. And without a baseline test, the lic Health Law, lead poisoning is not diag- is common in all courts: some effort to expert’s causation opinions are suscepti- nosed in children until the blood lead level quantify the exposure is required. In Cart- ble to exclusion. reaches 10 µg/dL. wright v. Home Depot U.S.A., Inc., 936 F. In Palmer v. Asarco Inc., 510 F. Supp. 2d Supp. 900, 902 (M.D. Fla. 1996), the plain- 519, 530 (N.D. Okla. 2007), the defendants Courts Insist on Proof of Causation tiff’s expert toxicologist opined that the challenged a neuropsychologist’s causa- In lead exposure litigation, proof of specific defendant’s paints caused his asthma. tion opinion on the ground that she “must causation is the plaintiff’s single biggest While the plaintiff’s toxicologist identi- know what plaintiffs’ educational abili- stumbling block to recovery. The New Jer- fied several components of the paints that ties would be without any exposure to lead sey Supreme Court described it this way: were known respiratory irritants, he pro- in order to testify.” The court agreed that By far the most difficult problem for vided no information as to how much of “[t]his is true for certain types of injuries, plaintiffs to overcome in toxic liti- the particular components the plaintiff such as IQ loss because, without pre-expo- gation is the burden of proving causa- had been exposed. Likewise, he failed to sure testing, any opinion that plaintiffs tion. In the typical tort case, the plaintiff “provide any quantification to substanti- have lost IQ points is purely speculative.” must prove tortious conduct, injury and ate in scientific terms what level of expo- Id. Thus, while the expert could testify that proximate cause. Ordinarily, proof of sure would have been sufficient to cause the plaintiff has a cognitive deficit as com- causation requires the establishment of asthma in the plaintiff or anyone else.” Id. pared to the general population, she could a sufficient nexus between the defend- at 904. The court granted the defendant’s not testify that the deficit is attributable to ant’s conduct and the plaintiff’s injury. motion to exclude the plaintiff’s toxicology lead exposure. In toxic tort cases, the task of proving evidence, stating: Similarly, in Adams v. Rizzo, 831 N.Y.S.2d causation is invariably made more com- Plaintiffs cite no authority for the prop- 351, 2006 WL 3298303 (N.Y. Sup. 2006), the plex because of the long latency period ositions that irritating chemicals in latex court highlighted a common mistake of of illnesses caused by or paints become bioavailable in relevant plaintiffs in attempting to prove specific other toxic chemicals. The fact that ten amounts, that actual exposure levels causation:

For The Defense n February 2008 n 45 Y o u n g L a w y e r s

Judging from these statements and com- Circuit Court of Appeals upheld the rejec- themselves to a Daubert challenge. In Farris ments made by plaintiffs’ counsel dur- tion of proffered expert testimony in Wills v. Intel Corp., 493 F. Supp. 2d 1174 (D.N.M. ing depositions and at oral argument, v. Amerada Hess Corp., 379 F.3d 32 (2d Cir. 2007), the defendants challenged the cau- it appears that plaintiffs hold the view 2004), because the expert failed to weigh sation opinions of the plaintiff’s general that once constructive or actual notice alternative explanations. In that case, the practitioner. The court noted that clinical is established together with “elevated widow and executrix for a seaman who experience does not provide support for an blood lead levels” any and all injuries, died of cancer alleged that her husband’s opinion requiring experience in epidemi- disabilities, syndromes or cognitive- cancer had been caused by exposure to ology or toxicology. Id. (citing Siharath v. intellectual-behavioral problems are and other alleged carcinogens Sandoz Pharms. Corp., 131 F. Supp. 2d 1347, during his work aboard the defendants’ 1351 (N.D. Ga. 2001)). vessels. The expert failed to account for In framing the Daubert attack on treating other cancer risks in his conclusions—in physicians, defense counsel should focus on Regulatory standards particular, cigarette smoking and alcohol the treating doctor’s lack of qualifications in consumption—and the court struck his the areas of toxicology and epidemiology. do not provide compelling opinions. Id. at 50. Despite otherwise impressive résumés, clin- Defense practitioners should be on the ical practitioners generally are unqualified evidence of injury-causation lookout for novel theories unsupported by to opine about causation issues in lead ex- reliable scientific literature. The court in posure cases, especially when the treating thresholds for litigation. Palmer v. Asarco Inc. excluded the causa- physician has not published articles or case tion testimony of a neuropsychologist as studies or conducted any other research on unreliable. The proposed testimony alleged the effects of lead exposure or has limited exclusively and dispositively linked to a link between lead exposure and ADHD. experience in treating patients with lead ex- lead exposure and the defense is fore- Id. at 531. However, the court described posure injuries. See Leathers v. Pfizer, Inc., closed from discovery on the issue of this testimony as “a novel scientific the- 233 F.R.D. 687 (N.D. Ga. 2006). damages and neurodevelopmental prob- ory and there does not appear to be any In the majority of federal circuits, experts lem causation. This court disagrees. support in the scientific literature for [the must be qualified on an opinion-by-opin- Id. *12. The court instead concluded that doctor’s] claim that lead exposure is a rec- ion basis. More and more courts disallow “[t]he generally accepted view that lead is a ognized cause of ADHD.” Id. According treating physicians to use their medical health hazard and may have an association to the court, even if the doctor “believes degrees to opine beyond their expertise. with the alleged injuries does not equate this link exists, without scientific support Having a medical degree is not sufficient with prima facie proof that lead exposure and research cited in her expert report to qualify an expert to testify about every was a substantial factor in causing the inju- and deposition this opinion is classic ipse medical question. O’Conner v. Common- ries alleged herein to these plaintiffs.” Id. dixit, and any testimony that lead expo- wealth of Edison Co., 807 F. Supp. 2d 1376, (emphasis added). sure caused ADHD will be excluded.” Id. 1390, aff’d, 13 F.3d 1090 (7th Cir. 1994); The expert must explain why exposure Similarly, in Veloz v. Refika Realty Co., 831 see also Porter v. Whiehal Lab., Inc., 9 F.3d to a lead-containing toy—and not some N.Y.S.2d 399, 2007 N.Y. Slip Op. 01980 (N.Y. 607, 614–15 (7th Cir. 1993) (excluding a other environmental factor—caused the App. Div. 2007), an expert failed to support doctor’s causation opinion because the plaintiff’s elevated blood-lead levels. Fail- his general causation opinion because he doctor admitted that the area in question ure to weigh alternative causes for a plain- “[did] not cite any particular scientific lit- was outside his expertise). Courts require tiff’s injury is proper grounds for excluding erature, nor [did] he identify which impair- experts to have “special knowledge” to a plaintiff’s specific causation testimony. ments were so described, who so described opine on a topic within a sub-specialty of In Bunch v. Artz, 2006 WL 2411428 *1 (Va. them, the similarity of those so described a discipline. Cir. Ct. 2006), a lead paint case, the defend- to those he saw in plaintiff, and at what ants sought discovery requesting that the level of exposure to lead such impairments Limit the Toxicologist “mother, Ms. Bunch, provide ‘[e]ducational have been observed.” Specific causation generally falls within the history of parents and siblings, and poten- expertise of a toxicologist because toxicol- tially other family members if there is a Rein In the Treating Physician ogy is “the study of adverse effects of chem- history of learning problems or special Like the overreaching neuropsycholo- icals on living organisms.” Casarett and education.’” Id. (citations omitted). The gist, courts often are skeptical of treating Doull’s Toxicology: The Basic Science court granted the request, finding that physicians who opine about causation in of Poisons 13 (Curtis D. Klassen ed., 5th the evidence was relevant to “determin- toxic exposure cases. Defense practitio- ed. 1996). ing whether any deficits the plaintiff may ners should closely scrutinize the opinions But even toxicologists may be limited have are solely the result of lead poisoning of treating physicians, looking for causa- in their ability to opine about the level or whether other factors, such as his moth- tion opinions. of lead absorption into the bloodstream er’s intelligence and education, are con- Most treating physicians fail to consider from different types of lead-containing tributing factors.” Id. Similarly, the Second the dose-response relationship, exposing toys. One of the inherent characteristics

46 n For The Defense n February 2008 of lead is that it leaves no identifiable trac- enced with the toxin at issue). Thus, if the • Determine whether the proffered testi- ers; thus, identifying the specific source plaintiff’s toxicologist lacks experience in mony will assist the trier of fact; of lead found in a plaintiff’s bloodstream lead poisoning, particularly in children, • Determine whether the expert is is usually impossible. According to one defendants should challenge the expert’s qualified; expert, the “bioavailability [of lead] oper- qualifications. • Use the traditional Daubert factors as a ates via a set of biological, biochemical and Finally, under Daubert, a toxicologist starting point and decide whether the physico-chemical processes that will often must employ the same level of scientific factors are appropriate; render starting forms of lead in pigments rigor in the courtroom as he or she would • Consider whether other factors, not men- indistinguishable in toxicokinetic terms.” in the laboratory. In a lead toy case, a tox- tioned in Daubert, are relevant; Thomas v. Mallett, 701 N.W.2d 523, 536 icologist should at least rely on materials • Consider whether the expert’s opinion (Wis. 2005). Because the uptake, distri- and studies based on lead poisoning among is: bution, retention, and excretion of lead is children. While there are numerous materi- • based upon facts consistent with the identical whatever the lead’s source, a tox- als arising out of lead-based paint litigation undisputed facts; icologist who claims to be able to identify used in homes, concern over lead in toys is • supported by reliable source data and the source of lead responsible for the harm a relatively recent phenomenon. As a result, supportable, reasonable assumptions based solely on blood contamination is “scientific” studies in this area are scarce. of the type normally relied upon by subject to exclusion. Thus, a toxicologist in a lead toy case who experts in the field; Just like the treating physician, a toxi- analogizes his or her opinions to lead paint • based upon an approach that employs cologist may have an impressive résumé, exposure may reach too far. Ingestion of the same level of intellectual rigor one that suggests sufficient training, skill lead-paint chips is quite different from a that characterizes the practice of the and experience to practice toxicology, but child ingesting lead from toys. expert in the relevant field. still be disqualified in your lead expo- Exclusion of expert testimony can be sure case if he or she lacks specific know- Conclusion achieved by finding and focusing on a ledge and experience about lead exposure. Recent product liability cases suggest some weakness in the expert’s person and/or See, e.g., Wintz v. Northrop Corp., 110 F.3d defenses to expert testimony proffered in opinion. It is important for practitioners 508, 514 (7th Cir. 1997) (finding a toxicol- lead-exposure litigation. The practitioner to think creatively and to exploit as many ogist unqualified to testify regarding an should: of those areas as possible. In the context infant’s abnormalities because the expert • Consider whether the expert’s testimony of lead exposure, due to its indeterminate was not a licensed physician, lacked exper- relates to scientific, technical, or other nature, savvy defendants should have a lot tise in genetic disorders, and was inexperi- specialized knowledge; of arrows in their quivers.

For The Defense n February 2008 n 47