biomonitoring: its expanding role in public health evaluations and litigation

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Biomonitoring: Its Expanding Role in Public Health Evaluations and Litigation

American Chemical SocietyNational MeetingMarch 26, 2009

Presented by:

LEONARD S. KURFIRST

© 2009 Wildman, Harrold, Allen & Dixon LLP.

DISCLAIMER

The purpose of today’s presentation is to give you an overview of bio-monitoring and its use in litigation, not to provide legal or scientific advice to any person or corporation.

For questions you may have regarding facts or scenarios applicable to you or your company, you will want to consult with a qualified attorney or consultant.

General observations contained within this outline do not reflect the opinions of Wildman Harrold Allen & Dixon or the American Chemical Society.

Different jurisdictions may have different rules and laws than those mentioned within this presentation.


Biomonitoring Defined

Biomonitoring is a scientific technique for assessing human exposures to natural and synthetic chemicals, based on sampling and analysis of an individual's tissues and fluids.

While blood, urine, breast milk and expelled air are most commonly measured, hair, nails, fat, bone and other tissues may also be sampled.

Chemicals that have entered the human body leave markers reflecting this exposure. The marker may be the chemical itself. It may also be a breakdown product of the chemical or some change in the body that is a

result of the action of the chemical on the individual. http://www.biomonitoringinfo.org


American Chemistry Council Position

ACC supports science-based biomonitoring programs and the responsible and appropriate use of biomonitoring information in assessing risk, creating public policy and communicating findings to the public

Biomonitoring is a promising public health tool that can help us better

understand human exposure to a wide range of substances.

Like all potentially useful tools, biomonitoring has limitations. Biomonitoring provides a snapshot of substances present in the body at a single point in time, but it alone does not tell us where a substance came from, when a person was exposed to it, the amount of exposure over time, or if there will be any health

effects. http://www.americanchemistry.com/s_acc/sec_mediakits.asp?CID=216&DID=565


Public Health Considerations

Center for Disease Control


CDC’s Third National Report on Human Exposure to Environmental Chemicals 2005

Primary Policy Objectives– To determine which chemicals get into Americans and at what

concentrations– For chemicals with a known toxicity level, to determine the

proportion of the population with levels above those associated with adverse health effects

– To establish reference ranges that can be used by physicians and scientists to determine whether a person or group has an unusually high exposure

– To assess the effectiveness of public health efforts to reduce exposure of Americans to specific chemicals

– To track trends over time and set priorities for research on human health effects of exposure

http://www.cdc.gov/exposurereport/pdf/thirdreport_summary.pdf


CDC’s Third National Report on Human Exposure to Environmental Chemicals 2005

Scope and Conclusions– The Third Report presented biomonitoring exposure data for 148

environmental chemicals over the period from 1999–2002.– The CDC measured chemicals or their metabolites in blood or

urine samples from a random sample of 5,000 participants from the National Health and Nutrition Examination Survey (NHANES).

– Chemicals analyzed included various pesticides/herbicides, heavy metals, dioxins, PAHs, phthalates and phytoestrogens

– CDC cautioned that “just because people have an environmental chemical in their blood or urine does not mean that the chemical causes disease.”

– CDC concluded that for most of the chemicals studied, more research is needed to determine if the reported exposures are a cause for health concern.

http://www.cdc.gov/exposurereport/pdf/thirdreport_summary.pdf


Biomonitoring Reported in the Press

A recent study looked at BPA concentrations in the urine of 2,157 adults and children older than 6 years of age. 92% of those sampled had BPA in their urine.

Laboratory tests of the umbilical cord blood of 10 newborns foundan average of 200 chemicals that can cause cancer, brain damage, birth defects and other health ailments, according to a study sponsored by the Environmental Working Group.

A National Geographic writer chronicled his efforts to learn what chemicals were in his body. He was told that a fire retardant, PBDE, was found in his blood at levels 10 times the average found in a small study of US residents.

While creating fear in some, none of these studies demonstrated that the levels of chemicals detected posed any risk of harm.


Problems With Data Interpretation

As noted by Dr. David Galbraith in his 2005 presentation to the International Society of

Regulatory Toxicology and Pharmacology: “Our vastly improved abilities to detect have often outstripped our abilities to detect meaning.”

This observation is equally applicable to the use of biomonitoring in litigation.


Biomonitoring and Litigation


Exposure/Dose Concepts in Litigation

Exposure– The amount of a substance that is available for uptake into the

body. It’s outside the body, such as an open bottle of vodka.

Dose– The amount of a substance that passes through a portal of entry

and actually gets into the body, such as drinking a shot of vodka.

Before biomonitoring, toxic tort lawyers and experts had little option but to use soil, air and groundwater sampling to determine exposure and then estimate dose.

Knowing a plaintiff’s actual dose through biomonitoring, however, is still a relatively small piece of the larger puzzle in toxic tort litigation.


Proving Causation In Litigation

General Causation– Established by demonstrating that a certain chemical is

capable of causing injury.

– Almost always requires epidemiological evidence. Dose is not important at this stage.

Specific Causation– Once the chemical has been “ruled in” as a possible

cause of a person’s illness, then the plaintiff must prove that the dose, which can be established through biomonitoring, was sufficient to cause the injury.


Biomonitoring Evidentiary Flaws

Difficult to Connect Results to a Specific Source– Dioxins and PAHS, for example, are generated by incomplete combustion

and are ubiquitous in our environment. Diet is generally recognized as the greatest source of these chemicals

– It is common for many litigation experts to ignore alternative source

Sound Epi Studies Don’t Exist for Many Chemicals– A “high” or “elevated” dose, in comparison to others, does not mean the

dose is sufficient to cause injury.– Animal and in-vitro studies are of limited applicability

Temporal Disconnect Between Results and Disease – Many of the diseases alleged in toxic tort litigation, such as cancer, have

latencies of 10 years or longer.– Dose measured at the time of litigation seldom proves the extent of past

exposures.


Paulson v. 3M (Minnesota state court)

Plaintiffs sought compensation for “subcellular” injury allegedly caused by long term exposure to 3M’s PFCs.

Plaintiffs admitted that they were not “sick”, but presented biomonitoring evidence of PFCs in their blood.

Plaintiffs’ experts testified that plaintiffs’ PCF exposures were sufficient to cause “subcellular” damage and put plaintiffs at risk for illness in the future, but no evidence of such damage was shown in any specific plaintiff.

The Court in Paulson dismissed the plaintiffs’ claims as speculative, holding that no injury had been demonstrated. The mere presence of chemicals in the blood was not sufficient to show actual injury.

WHAT IF SUBCELLULAR IMPACT HAD BEEN SHOWN?


New Trends in Biomonitoring


Toxicogenomics

The study of how the human genome reacts to environmental stressors and toxicants on the subcellular level.

Claims have been made that toxicogenomics will “provide precise causation proof in toxic tort cases, environmental bodily injury cases and workers compensation claims that dose-response and epidemiology studies cannot match.”* Such claims may be overly optimistic.

Recently, two types of toxicogenomic analyses have begun to appear in litigation– DNA Adduct testing

• Most commonly applied to PAH exposures

– Cytokine testing• Presently used to “rule” out exposure to benzene and chromium 6

*Dr. Bruce Gillis, Mealy’s Emerging Toxic Torts, Vol. 16, #24, March 18, 2008


DNA Adducts

In biology, an adduct is a complex that forms when a chemical binds to a biological molecule, such as DNA or protein

Diagram provided by Angela Harris of CTEH


DNA Adduct Studies: Findings

Efforts to correlate increased DNA adduct levels with increased risks of disease have led to inconclusive results.

One of the foremost researchers in this field, Dr. David Phillips, made the following observation:– “Given the multistage nature of tumor induction, it would be very

surprising if a single parameter, such as DNA adduct levels, could provide a quantitative estimate of human cancer risk.”*

*”DNA Adducts of Markers of Exposure and Risk,” 577 Mutation Research, 284-292, (2005)


Specific Problems with DNA Adduct Testing

Levels of adducts in white blood cells are a reflection of exposure and individual ability to accumulate adducts.– Ability to detoxify active metabolites of PAHs– Ability to repair (i.e. remove) bulky DNA adducts

DNA adducts in white blood cells do not predict levels in target tissues.

DNA adduct levels have not been shown to correlate with house dust PAH levels.

Same problems as earlier biomonitoring– Difficult to Connect Results to a Specific Source– Temporal Disconnect Between Results and Disease


Cytokine Testing

Cytokines are proteins that are produced when cells come into contact with foreign substances.

Thus far, cytokine signatures have been identified only for benzene and chromium 6. Work is underway to identify signatures for other chemicals, but the process is expensive.

Cytokine testing is subject to many of the same problems affecting DNA adduct testing. Essentially, it can be used to show exposure to a certain chemical on a subcellular level, but not much more.

No one has yet developed a biomonitoring test that analyzes a person’s blood, tissue, bone marrow or urine and can accurately trace back said person’s disease or illness to a particular exposure.


Judicial Response

Most states require a plaintiff to have an actual physical injury, disease, pain or other impairment in order to pursue a claim for personal injury.

While a handful of states have allowed plaintiffs to proceed based upon nothing more than damage to their DNA, the majority rule is that a clinical symptom or disease is necessary before a personal injury claim exists.

In Rayner v. Union Carbide Corp, 402 F. 3d 608, the Sixth Circuit expressed concern that such litigation, if allowed, might encompass a very large percentage of the total population since the average American is exposed to “chemically processed foods, toxic fumes, genetically modified fruits and vegetables, mercury laden fish and hormonally treated chicken and beef.”


Other Trends

Comparison of dioxin levels in blood– Usually, an attempt is made to compare total dioxin teqs in the

blood of a control group with the blood of people living next to an industrial defendant.

– Data is sometimes compromised by a high percentage of laboratory non-detects or flawed methodology, especially studies funded by litigants.

– Studies conducted by the ATSDR (Calcasieu, La.) and the University of Michigan (Dow Midland study) demonstrated that diet and age were the two factors that affected dioxin blood levels the most. There was no statistical correlation between the amount of dioxins found in house dust and dioxins found in blood.


Other Trends

Hydroxypyrene Testing– Pyrene is a PAH. When a person receives a dose, either through

inhalation or dermal absorption, his or her metabolism will transform the pyrene into 1-hydroxypyrene (1-OHP), which is quickly excreted through the urine.

– 1-OHP has been used as a biological indicator of PAHs.

– While medical studies have suggested that urinary 1-OHP will increase along with increased exposure, especially dermal exposure, there once again is an absence of any epidemiological evidence that connects the level of 1-OHP in the urine with health risk.

– Temporality with injury and alternative sources are again problems that make it difficult to use such testing effectively in litigation.


Conclusions

Biomonitoring is useful for demonstrating exposure, but is by no means “proof” of injury or causation.

Biomonitoring serves as an important tool in public health assessments, but has limited utility in toxic tort litigation.

Once the database of biomonitoring results fills out, and the science of epidemiology catches up, biomonitoring may be more useful for proving causation.

© 2009 Wildman, Harrold, Allen & Dixon LLP. 25

Thank You

Thank you for the opportunity to share with the American Chemical Societyour insights on biomonitoring and public health evaluations

Leonard S. Kurfirst, PartnerWildman, Harrold, Allen & Dixon LLP225 West Wacker DriveChicago, IL 60606-1229T: 312-201-2702F: [email protected]

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