Category: Litigation

Lab beakerMy previous post began a conversation about applying the evidentiary rules for admissibility of scientific studies and expert testimony to the emerging studies on the health and environmental effects of nanomaterials, all in the context of the toxic tort litigation that is soon to come.  This post will continue that conversation by looking at the legal rules to determine the reliability and scientific validity of such studies.  In particular, this post will look at the Frye rule and its continuing viability in a significant minority of jurisdictions.

Under the older Frye rule, reliability was determined solely by whether the scientific technique has achieved “general acceptance in the particular field in which it belongs.”  Frye v. United States, 293 F. 1013 (D.C. Cir. 1923).  States that have adopted and continue to apply the Frye test for admissibility of expert evidence have further clarified and refined the rule.  Thus, the Minnesota Supreme Court stated in Goeb v. Tharaldson, 615 N.W.2d 800, 810 (Minn. 2000), that a two-pronged test would apply:  “First, [the] technique must be generally accepted in the relevant scientific community, and second, the particular evidence derived from that test must have a foundation that is scientifically reliable.”  In Goeb, the plaintiffs alleged that their son had suffered permanent injuries from exposure to a pesticide that had been applied in their residence.  The court agreed that the trial court had properly excluded the plaintiffs’ expert scientific evidence of causation because the scientific methodology used was not generally accepted and because the expert’s analysis had no “independent validation.”

The Frye rule has frequently been criticized, however.  Thus, the Alaska Supreme Court (in a case adopting the Daubert rule and the federal evidentiary standard), has criticized Frye as incorrectly favoring the conclusions of scientists over courts in matters of a legal nature, arguing that it “ ‘abdicates’ judicial responsibility for determining admissibility to scientists uneducated in the law.” See State v. Coon, 974 P.2d 386, 392, 394-95 (Alaska 1999).  The Minnesota Supreme Court countered this argument by stating that “the Frye general acceptance standard ensures that the persons most qualified to assess scientific validity of a technique have the determinative voice.”  Goeb, at 813.  In Blackwell v. Wyeth, 971 A.2d 235 (Md. 2009), the Maryland Court of Appeals established a compromise rule.  In Blackwell, the plaintiffs alleged that their child’s autism was caused by thimerosal in childhood vaccines.  The court reaffirmed its adherence to the Frye doctrine, characterizing the doctrine in Maryland as requiring that “[g]enerally accepted methodology . . . must be coupled with generally accepted analysis” by the expert.  This approach thus assures that the trial judge has the final word on acceptance of the evidence.

The debate continues, however, over whether the Frye doctrine relies on excessive deference to the scientific community on matters of a legal nature.  This disagreement is not likely to be resolved soon and is reflected in the split in the states over the adoption of the Daubert rule, which, in contrast, is heavily dependent on judges to evaluate the scientific evidence.

What will happen to nanotechnology studies in a Frye jurisdiction?

The answer may depend on whether the studies are viewed as new and untested because they involve materials at a scale that has generally not been previously studied for health and environmental impacts.  Frye does not favor new technologies.  Frye admissibility is premised upon a history of the technologies that has evolved to the point of receiving general acceptance in the particular scientific community.

On the other hand, an argument could be made that such studies are simply versions of well-established and generally accepted scientific studies, whether of an epidemiological nature (statistical studies of human populations) or a toxicological nature (such as studies on mice conducted in a laboratory).  It is worth noting, too, that studies of human populations generally take much longer to develop, and nanomaterials measurable in consumer products and the environment are a relatively new occurrence in the scheme of things.  Thus, the studies on nanomaterials now emerging are laboratory experiments.  See, for example, the studies summarized in Powell & Kanarek, Nanomaterial Health Effects – Part 1:  Background and Current Knowledge, 105 Wisc. Med. J. 16 (2006).

In the next post, I will examine the Daubert reliability standard.

Many of my posts have talked about the need for studies on the health, safety, and environmental effects of nanomaterials.  But it has been a long time since I raised the question of what these studies may mean for toxic tort litigation.  As in any litigation, the evidence, including scientific studies and the experts who interpret them, must be admissible under the relevant rules of evidence.  In the United States, there are two basic approaches to the admissibility of expert evidence in the courts – (1) the federal courts’ approach, which is governed by the Federal Rules of Evidence and a trio of cases beginning with Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), and (2) the approach known as the Frye test.  Regardless of the approach used by the particular court considering the evidence, early studies that may demonstrate health or environmental risks associated with nanomaterials will have an uphill battle for admissibility in the courts.

Over the next month, I intend to discuss some of these issues in a series of posts.  This post will consider the first question:  What is it about this evidence that will be so difficult for the courts?

To begin with, let’s briefly look at the rules for admissibility of the evidence in court:

 1.  Frye Test:  This test derives from the case of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), a criminal case that involved a scientific lie-detection technique that was a sort of precursor to the modern lie-detector tests.  The court there said that “while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.”  Thus, courts view as admissible under this test only expert evidence derived from scientific studies or techniques in general use, and usually long-standing use, in the particular field, and which most experts in the field recognize as being reliable.

 2.  Daubert Test:  The Daubert case itself was a toxic tort, a prescription drug product liability action, so the Supreme Court had before it on the record scientific studies that resemble the kinds of studies of exposure-and-outcome that might be produced for nanomaterials.  The Supreme Court held that the test for admissibility of expert evidence under the Federal Rules is broader than the Frye test and requires that the proponent of the evidence demonstrate that it be reliable – i.e. that it be scientifically valid – and that it be relevant to a particular issue in the case, not that it merely be suggestive of health problems.  The Court emphasized that the trial judge is the “gatekeeper” who must make a determination at an early time in the litigation as to whether the expert evidence is admissible.  If it is not admissible, often plaintiffs’ cases are dismissed prior to trial.

 What evidentiary challenges will nanomaterial studies present?

 ●  The studies will provide only probabilistic evidence.  This means that the studies will only show statistical associations (probabilities) between exposure to a particular nanosubstance and a particular outcome (e.g. illness).  While the extent to which probabilistic evidence differs from traditional forms of proof in tort cases (such as motor vehicle accidents) is a matter of degree, the inability of the studies to confirm the causal relationship between exposure to a substance and the illness the plaintiff suffers will be problematic for plaintiffs’ cases.

 ●  The illnesses are likely to be “generic.”  Some substances previously studied are linked to “signature diseases,” which occur very rarely in the general population, but with greater frequency among people exposed to the substance.  Silicosis (silica dust), asbestosis (asbestos), and pleural mesothelioma (asbestos) are examples.  But most cancers, respiratory conditions, and neurological disorders, for example, are caused by a variety of triggers, some related to exposures, others genetic or idiopathic.  It is therefore difficult to differentiate those caused by a particular exposure and those arising for other reasons.

 ●  The nanostudies will be new.  Under either admissibility test, new and untested or unreplicated studies may not pass muster.  In toxic torts, history has shown that early plaintiffs may have considerable difficulty with the admissibility of their evidence; even if the evidence is ruled admissible, problems of proof arise because juries may not view the early evidence as having much weight.   As time goes on, these studies may gain more acceptance in the field – or, they may be proved to be aberrations.

 Next up:  Admissibility and scientific reliability of nanostudies.

nano 5

In an earlier post, I wrote about the consternation surrounding patents on genes and the potential implications to the developing realm of nanotechnology.  Recently, an amicus brief was filed with the Federal Circuit by the Department of Justice (DOJ) opposing the patents that were issued to Myriad regrding the testing for breast and ovarian cancer.  Interestingly, the United States Patent and Trademark Office (USPTO) did not join the DOJ, which indicates an idealogical rift in the Obama administration.  It was reported that Mr. Kappos, current director of the USPTO, ”seemed chagrined that the Department of Justice was taking a viewpoint very different from the patent office.”

The following is an excerpt from the amicus brief Table of Contents which is rather revealing and informative regarding the government’s opinion on the matter:

A. Section 101 Embraces Only “Human-Made Inventions”
B. Engineered DNA Molecules, Including cDNAs, are Human-Made Inventions Eligible For Patent Protection
C. Isolated But Otherwise Unmodified Genomic DNA Is Not A Human-Made Invention
1. Unmodified Genomic DNA Is A Product Of Nature
2. “Isolation” Does Not Transform A Product Of Nature Into A Man-Made Invention
3. Isolated Genomic DNA Is Not Patent-Eligible Merely Because It Is A Literal Composition Of Matter
4. Isolated Genomic DNA Is Not Rendered Patentable On The Theory That It Is “Pure”
5. Isolated Genomic DNA Is Not Patent-Eligible Merely Because It Is Useful Or Requires Investment To Identify

It is important to note that the DOJ is not advocating an all-out ban on patents on genes, just those that are ‘unmodified.’  Initially, this will allow for further development of the information contained in the genomic code.  It seems as though the big argument revolves around the pieces of the code that are isolated, but not changed in any way.  Proponents assert that there should not be the reward of patent protection based solely on finding that which already naturally occurs.  Opponents argue that invention and development of specified uses for these segments of DNA would be stiffled, and the United States’ position as a global leader in the life sciences would be severely compromised.

It will be interesting to watch the development of the subject matter as it works its way through the Federal Circuit, and presumably the Supreme Court.  Not only for the impact it will have on the biotechnology arena, but also on nanotech.  As mentioned before, many argue that the majority of inventions involving nanotechnology do not qualify for patent protection because they are not far enough removed from the naturally occurring material they are comprised of.  We shall see.

Link to the DOJ brief:

The course of asbestos litigation is well known, as is the fact that there appears to be no end in sight.  Is nanotechnology producing the next asbestos?  Some groups are working to prevent nanoparticle litigation from following in the steps of asbestos litigation.

In 2009, the United Kingdom’s Institute of Occupational Medicine (IOM) issued a report asking the question whether High Aspect Ratio Nanoparticles (HARN) – most notably, carbon nanotubes – create some of the same health risks as asbestos fibers.  The fiber-like features of HARN, although man-made rather than naturally occurring, may or may not interact with the human body in asbestos-like ways. The importance of determining whether HARN raise similar health risks cannot be overstated.  These issues have yet to be resolved, with potential health risks lurking in the interim.  As is often the case, development of new technology has flown past the scientific community’s ability to determine and assess the technology’s risks.

Looking back at the history of asbestos litigation, some burning questions need resolution sooner rather than later.  For example:

●  Do HARN fibers remain in vivo or do they degrade before disease processes are initiated?

●  If HARN are shown to persist in the body, what is the likely impact on workers?  In the asbestos context, the impact was seen in thousands of workers who developed debilitating progressive obstructive lung disease and/or malignant mesothelioma.  Do HARN have the capacity to produce similar health problems?

●  Even if HARN do not appear to behave directly like asbestos fibers, could HARN cause other, unknown, adverse health effects?

●  What broader impact might HARN have outside the workplace, including consumer and environmental exposures?

Are we headed down the same litigation road with HARN that we traveled with asbestos?

The asbestos litigation debacle in the United States began modestly enough with workers’ compensation claims, which were first denied and eventually routinely paid.  When asbestos insulation workers successfully brought actions against the manufacturers of the products they used in the workplace, the litigation expanded exponentially and has continued to challenge the court systems.

How can we avoid another asbestos?  The answer begins with research, knowledge, and awareness.



The nexus of a large number of nanotech inventions, specifically related to personalized medicine, is biological material and other naturally occurring materials.  In order to obtain a patent, the inventor is essentially required to create a new composition of matter from that which occurs naturally.  Until recently, scientists and inventors alike have been able to satisfy this requirement, but change might be on its way.

In May 2009, the American Civil Liberties Union and the Association for Molecular Pathology filed suit, in the United States District Court for the Southern District of New York, against the United States Patent and Trademark Office and Myriad Genetics. The complaint pertained to patents that were granted on the BRCA1 and BRCA2 human genes that are mutations correlated to the increased risk of breast or ovarian cancer.  Myriad Genetics designed a procedure to test for these mutations to indicate the likelihood of a woman developing either or both of the diseases.  The complaint asserted that patents on genes should not be allowed because they are violative of § 101, patentable subject matter, of the Patent Act, namely all three of the judicially recognized exceptions to patentability:  natural phenomena, laws of nature, and abstract ideas. Subsequently, the American Civil Liberties Union and the Public Patent Foundation filed a motion for summary judgment, in August 2009.  On March 29, 2010, the District Court found that the isolated segments of DNA utilized for the diagnostic tests were “not markedly different from native DNA as it exists in nature” and held the patents granted to Myriad were not valid.  Ass’n. for Molecular Pathology v. U.S.P.T.O., 702 F. Supp. 2d 181 (S.D.N.Y. 2010) available at

This particular case involved the nature of medical tests utilized to screen women for the specific types of cancer.   Myriad holds (held) patents on the two genes that indicate the likelihood of the woman developing cancer.  Two main issues precipitated the litigation.  First was the fact that Myriad charges more than three thousand dollars for its exclusive Comprehensive BRACAnalysis test.  This exorbitant cost prohibited many women from being able to have the test, placing them at an increased risk of developing cancer.  It was asserted that if Myriad would license the test, the cost would become more reasonable and allow for more women to benefit from the technology.  This is the specific goal of personalized medicine; however that goal is more often thwarted by the exclusionary nature of patents (absent licensing and/or collaboration).

The second concern arose from those women who actually undergo testing and are delivered a positive diagnosis for possible development of cancer.  Because Myriad held the patent on the test, the women were prevented from obtaining a second opinion to confirm the results prior to deciding to undergo preventative surgery. Examples of such prevention include radical mastectomies and ovarian removal surgery.  The combination of these concerns cuts directly to the heart of the ongoing debate:

Should patents on biological material be allowed, and if so, what does that mean for the future of scientific research and the development of personalized medicine?

The precursor to this debate harkens back to the California Supreme Court case of Moore v. Regents of the Univ. of Calif., 793 P.2d 479 (1990), where the court was asked to decide if a cancer patient had any property rights in a commercially viable invention created from his particular cancer cells.  The court ultimately decided that the plaintiff did not have any property rights in his biological materials because they considered the material discarded.  The same debate takes place today with regard to human DNA, but no specific human has a specific property right to a specific segment of the human genome.  As a result, scientists are able to use raw DNA and patents on genes are issued if the inventor/scientist has isolated a particular gene from its naturally occurring form, essentially creating a new composition of matter.  However, in light of the decision in Myriad, the fate of thousands of patents (issued and pending) might be uncertain.

Of course, I will bring the focus back to the challenges awaiting nanotechnology in the fields of personalized medicine, molecular biology, etc.  As I stated in the beginning of this post, the nexus of a large number of nanotech inventions is biological material and other naturally occurring materials.  We know from the patentable subject matter paradigm, now including Bilski, that there still exists a broad spectrum of possibilities of what is considered a “new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof . . . .”  35 U.S.C. § 101.  But, is there restriction on the horizon as a result of the Myriad decision?  Only time will tell.    


The paradigm to determine the patentability of inventions involving nanotechnology and biotechnology continues to evolve due to the Supreme Court deciding the case of Bilski v. Kappos, 2010 WL 2555192.  The Court heard oral arguments on November 9, 2009, and the opinion was issued on Monday, 28 June 2010.

The trouble for Bilski began when he and his business partner, Warsaw, applied for a patent on a computerized method for incorporating weather information into the speculation of future prices of commodities and energy costs (business method). The claim was denied by the Patent and Trademark Office (PTO) for lack of patentable subject matter (process), and the denial was affirmed in subsequent appeals to the PTO and the Federal Circuit. The Supreme Court decision affirmed the denial of the business method’s patentability, but it simultaneously held the test, utilized by the Federal Circuit, for determining if a process is proper patentable subject matter was not the exclusive and sole determining factor. Going forward, this decision will have a major impact on what constitutes patentable subject matter (the first hurdle on the road to a patent being issued), including those discoveries that have helped to fuel the explosion of cutting-edge bio/nanotechnology.


Throughout the litigation history, the focus was squarely on the ‘machine or transformation’ requirements articulated by the PTO and further solidified by the Federal Circuit.  The court relied on the two prong test set forth in Gottschalk v. Benson to determine whether a process claim is tailored narrowly enough. “A claimed process is surely patent-eligible under § 101 if:  (1) it is tied to a particular machine or apparatus, or (2) it transforms a particular article into a different state or thing.” The Federal Circuit outlined the task at hand, “It is undisputed that [Bilski’s] claims are not directed to a machine, manufacture, or composition of matter. . . . Thus, the issue before us involves what the term ‘process’ in [the law] means, and how to determine whether a given claim . . . is a ‘new and useful process.’”  Essentially, the legal issue generating all the consternation and strife is: “[W]hat test or set of criteria governs the determination by [PTO] or courts as to whether a process is patentable?”  The Federal Circuit opined that a process is not patentable subject matter unless it exactly conforms with the ‘machine or transformation’ test.


The Supreme Court agreed to hear the case, but rarely hears a case from the Federal Circuit to explain that they reached the correct and appropriate conclusion. Quite to the contrary, the Supreme Court seems to take case after case in the patent area to fix a wrong perpetrated by the Federal Circuit. This tension has been in place for quite some time.

At oral arguments before the Supreme Court, Justice Sotomayor voiced concern over the harsh majority opinion of the Federal Circuit:

How about we say something as simple as patent law does not protect business matters instead of what the Federal Circuit has begun to say, which is technology is tied to a machine or a transformation of the substance, but I have no idea what the limits of that ruling will impose in the computer world, in the biomedical world, all of the amici who are talking about how it will destroy industries?

That sentiment reverberated in the unanimous majority opinion whereby the ‘machine or transformation’ test was relegated to the role of a helpful clue in determining whether or not a process is patentable subject matter. Essentially, the Court rejected the Federal Circuit’s exclusive reliance on the bright-line rule and threw the proverbial ball back into their court to develop an appropriate test. The bottom line, as it stands now, is that patentable subject matter is still quite broad, and the analysis to determine it includes the ‘machine or transformation’ test as one criterion with regard to processes, but it no longer is the sole deciding factor.


If the Supreme Court had required strict adherence to the machine or transformation test, it would have had seismic implications for patents already issued, and certainly would have caused trouble for pending applications relating to biotechnology and nanotechnology.  The trouble arises from the precarious position that biotech and nanotech patents are not theoretically involved with either a machine nor do they transform matter.  Generally speaking, they are processes involved with analysis, diagnosis, treatment or some type of function. Notable examples are those nanoparticles involved in drug delivery. Even though the particles behave differently at the nanoscale level, they essentially are not transformed or part of a machine and would thus fall outside patent protection under the rigid Federal Circuit test. Now, there is a least the possibility for these types of inventions to move forward in the process of patentability.

Ultimately, the parties in Bilski did not receive the patent on the specific business method that was applied for; however, the patent world at large was able to avoid the strictures of the rigid, bright-line ‘machine or transformation’ test utilized by the Federal Circuit .  In essence, the fields of nanotechnology and biotechnology research and development dodged a catastrophic bullet. In the coming weeks and months I plan to return to this discussion in relation to emerging technology, especially after the PTO, practitioners, judges, and legislators have had time to digest the nuances of this landmark decision.

If you are not already familiar with Ron Wernette and his excellent blog, I recommend you add it to your nanolinks at

The blog keeps track of developments and learning opportunities in the field and is a perfect complement to our blog, as the blog’s mission statement demonstrates:

“The Nanotort Law Blog aims to be a useful resource for lawyers and risk managers. It will help you stay abreast of the current state of hazard assessment knowledge, pertinent governmental regulation, industry and NGO standards and guidelines, and other important information germane to environmental, health, and safety risks and potential liabilities. The Nanotort Law Blog will also offer ideas and links to other helpful resources to help you monitor, understand and manage the potential – and as yet unkown – liability risks of Nanotechnologies. “

Law sometimes happens in peculiar ways.  And none so peculiar as the Fifth Circuit Court of Appeals’ recent dodging of the important issues raised by climate change litigation.  What happened (or rather, didn’t happen) is so important that it merits a digression here.  It also suggests ways that courts can make law without seeming to make law, especially when the cases involve new claims, new theories, and even new technologies.  The Fifth Circuit’s maneuver should serve as a warning – and a reminder of the clever traps of procedure – to those who attempt novel theories in the era of new technology.

 Here’s what happened.  Property owners and other residents along the Mississippi Gulf coast brought a tort action against oil companies, electrical companies, and utilities, claiming that the defendants caused massive emissions of greenhouse gases that contributed to global warming, which, among other things, added to the power of Hurricane Katrina.  They sought compensation for property damage from Katrina.  The lower court dismissed the action on a pretrial motion, and the plaintiffs appealed to the Fifth Circuit Court of Appeals.  The 3-judge Fifth Circuit panel (“the panel”) reversed and held that the action could go forward, Comer v. Murphy Oil USA, 585 F.3d 855 (5th Cir. 2009), but that decision was vacated when the Fifth Circuit accepted the case for a full-bench (“en banc”) rehearing.  A number of judges recused themselves from the rehearing, presumably because of potential conflicts of interest with the case.  Last week, the Fifth Circuit said that because the court no longer had a quorum of judges, it was not empowered to rehear the case, so it dismissed the appeal and reinstated the lower court’s dismissal of the action.

 Is it really so easy to circumvent our judicial processes?

 Why is this procedural maneuver important, and what does it have to do with nanotechnology?

The net effect was to reinstate a lower court ruling over the Fifth Circuit panel’s own decision.  That lower court ruling was a dismissal of the lawsuit.  What was unusual was that the Fifth Circuit did this without considering the issues raised on appeal.  In other words, the case was decided on a technicality.  In so ruling, the Fifth Circuit rejected a variety of measures that would have allowed the rehearing to go forward.  If the court had wanted to continue with the rehearing en banc, it could have found a way.

 Nanotechnology tort actions will arrive in the courts soon enough, raising unprecedented issues (and yes, some old issues as well).  It is important that those issues (new and old) received full consideration.  The law favors deciding cases on the merits, not dodging difficult controversial and new issues.  Moreover, nanotechnology litigation will involve many industries, enormous and small, so the notion that judges may have to recuse themselves is not far-fetched.

 Most judges have past connections with big industry in this country, whether it is oil and utility companies, pharmaceutical companies, nanomaterial firms, or anything else.  They had clients who either were those companies or who were engaged in business or litigation with or against those companies.  They had investments of their own.  Their legal practices, government service, or other pre-judicial professional obligations involved them with many law firms and attorneys.  It is important that judges recuse themselves when there is the potential for a conflict of interest or even just the appearance of a conflict of interest.  But if courts will decline to hear cases because too many of their judges must recuse themselves, then the parties, and all of us, will end up on the losing side.

 And that’s not justice.

It is safe to say that the current state of nanotech litigation is embryonic.  There are only a handful of cases dealing with the validity of rules governing nanomaterials, and the results are
resoundingly similar – deference to the rule maker.  In Kennecott Greens Creek Mining Co. v. Mine Safety and Health Admin., 476 F.3d 94, 946 (D.C. Cir. 2007) (a three year old case that accurately represents the issue in the few cases brought before the courts), judicial review was sought regarding three regulations promulgated by MSHA. Specifically, the rules were implemented to require mining operations to utilize new engines that reduced the emission of diesel particulate matter, but it was argued that those same engines produced high levels of nanoparticle emissions  in the process.  On appeal, the court disagreed with the mine owners and took a complete deferential approach because the risks associated with nanoparticles, at this point, are speculative at best until further developments.

We should expect to see similar types of cases with the same results for some time or until there is solid proof of a substantial problem.

In June 2009, the EPA Nanomaterial Research Strategy released a list of eight questions that need to be considered to determine the risks involved with nanotechnology and quite possibly could become the nexus for non-deferential judicial opinions in the future.  Kristine L. Roberts, Nanotechnology and the Future of Litigation, LITIGATION NEWS,
Winter 2010, at 6, 8.  The list on page eight includes the following inquiries:

1) What advances in technology must occur to detect and quantify nanomaterials in the environment and biological material?
2) What are the major environmental impacts?
3) What are the exposure risks?
4) What are the effects on our health?
5) What are the ecological effects?
6) How many risk assessment approaches need to be amended/created?
7) Which nanomaterials have a high potential for release?
8)Can manufactured nanomaterials be utilized in a sustainable manner?

This list, at first glance, seems like a blunt tool when compared to the enormity of what it is attempting to procure.  However, this is one of the first proactive steps with regard to whom is going to be accountable for what in future ligation involving nanotechnology – litigation that should include more applicable standards based on
concrete information instead of automatic deference due to lack of knowledge.

In the call for studies on the health and safety of nanoparticles in various uses, it is easy to overlook important questions about what the studies mean.  Does a study demonstrating what may be considered an adverse outcome provide a basis for legal action?  The complex answer is, “Sometimes yes and sometimes no,” or in the words of every law professor, “It depends.”

Let’s take a look a highly publicized study published in late 2009.  See Trouiller et al., Titanium Dioxide Nanoparticles Induce DNA Damage and Genetic Instability In vivo in Mice, CANCER RES. 2009; 69: (22), Nov. 15, 2009.  Researchers from UCLA conducted a study in vivo on mice to test the effects of the titanium dioxide nanoparticles, regularly used in many consumer products, including cosmetics (especially sunblocks), food coloring, toothpaste, and paint.  The researchers herald their study as the first in vivo study to demonstrate a connection between the particular substance and genetic harm.  Previous in vitro studies, they say, produced mixed results and by their very nature did not involve living tissue.

First, a word about how the law views in vitro and in vivo studies.  In vitro studies, such as the Ames test, test the effects of chemicals on bacteria or other cells in a laboratory dish, looking for genetic mutations.  These studies are sometimes offered in a legal setting to suggest that exposure to the substance is carcinogenic in human, on the theory that somatic cell mutations lead to uncontrolled cell reproduction and, ultimately, cancer.  In vivo studies compare laboratory animals exposed to a particular substance to a control group that was not exposed, looking for differences in outcomes between the two groups.  What both types of studies have in common is that they do not involve humans.  As a result, they also have in common the need to extrapolate from the test data to predictable results in humans, a process that is speculative.  In other words, both studies fall short of demonstrating exactly what will happen when humans are exposed to the substance.  But both are relatively fast, inexpensive, and do not involve the ethical dilemmas of testing on humans.

Courts bristle when plaintiffs seek to introduce this kind of evidence, without anything else, in personal injury litigation as proof that exposure to a particular substance caused their illnesses.  The role of courts in determining what evidence is admissible under the rules of evidence is designed to keep frivolous suits from consuming resources and from reaching juries, which might be more impressionable than the court.  Regulators are less constrained than courts, however.  The role of government regulators is circumscribed by the legislation giving them authority.

In the scheme of things, the law prefers in vivo studies to in vitro studies because in vivo studies demonstrate some action of the substance on mammalian living tissue.  But both types of studies are a distant second to epidemiological studies on human populations.  Such statistical studies of risk factors examine groups of humans to determine the strength of relationships between exposures and outcomes.  But even they do not examine the direct impact of the substance on human tissues.

All scientific and statistical studies used to demonstrate carcinogenicity serve to demonstrate the difficulty the law has with understanding and using the studies to make legal decisions.  In the important U.S. Supreme Court case of Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), in which the Court provided guidance on determining the reliability of scientific studies in the federal courts (in the context of a toxic torts case involving the prescription drug Bendectin), the Court had the following to say about the distinctions between science and litigation:

[T]here are important differences between the quest for truth in the courtroom and the quest for truth in the laboratory. Scientific conclusions are subject to perpetual revision. Law, on the other hand, must resolve disputes finally and quickly. The scientific project is advanced by broad and wide-ranging consideration of a multitude of hypotheses, for those that are incorrect will eventually be shown to be so, and that in itself is an advance. Conjectures that are probably wrong are of little use, however, in the project of reaching a quick, final, and binding legal judgment – often of great consequence – about a particular set of events in the past.

Id. at 596-97.

There is strength in numbers, however.  The more reliable studies that are conducted showing similar results, the more likely the substance will be regulated effectively.  And the more likely litigants will be able to assemble a package of expert scientific evidence that will support their positions.


An abstract of the article may be found at