INSIGHT: Toxicology Experts in Litigation and Environmental Transactions

Toxicology is the study of adverse effects of chemical, biological, or physical agents on living systems, such as humans, farm animals, wildlife, and ecosystems.

While most toxicologists have similar core academic training, each toxicologist’s expertise is strongly shaped by their research experience, academic studies, experience in related sciences, and work history. Some toxicologists, for example, have exceptionally deep knowledge and experience in analytical chemistry, others in designing or conducting laboratory animal studies, and many in acute poisonings (like the experts who work at poison control centers). Other disciplines in which an individual toxicologist may have credible expertise include epidemiology, risk assessment, nutrition, ecology, statistics, and regulatory applications. Some toxicologists have been more specialized throughout their careers, while others have developed strong skills that can be applied more generally.

Of course some toxicologists have pre-existing knowledge about, and established positions on, certain aspects of the science related to a specific case or property. It is up to the retaining party to determine whether that is a strength or a limitation. In some situations, the gravitas of having an expert who has spent a career in the area being litigated could provide benefits like pre-existing knowledge that saves time and money on preparation, or greater credibility with a jury or judge. In other situations, though, an expert with a long-term focus of working, consulting, or serving as an expert in a narrow area may be perceived as a hired gun, or alternatively, may be so confident in his/her knowledge of the science that there could be a blind spot related to new literature that is inconsistent with his/her established position. A fresh perspective that incorporates an unbiased but in-depth review of the relevant science may be a stronger choice for some sets of facts.

Situations That Often Include an Expert Toxicologist

An expert toxicologist can bring valuable insights in many contexts, some of which include:

1. Contaminated property – Our country is littered with well-located property that has been contaminated with chemicals of various types, including:

• petroleum products from former gasoline stations, tank farms, and refineries;
• chlorinated solvents from former degreasing sites, dry cleaners, and other applications;
• lead, arsenic, and other metals from mines, steel mills, and countless other sources; and
• polychlorinated biphenyls and per- and polyfluoroalkyl substances.

Contaminants may have been released directly on the subject property or may have migrated from off-site, and current contamination may be in soil at the surface or subsurface, or in groundwater. Some properties may include water features and sediments that also could be affected, and contaminants also can find their way into air and vegetation. Current contamination may continue to migrate to other properties and to move between different media, moving among subsurface soil, groundwater, soil gas, or indoor air.

The right expert toxicologist can help you and your engineer:

• assess liability from the perspective of actual or potential health risk in light of current or planned future land uses;
• identify media and areas that may require remediation for planned land use;
• identify cleanup target levels;
• evaluate potential options to cut off or significantly reduce exposure pathways to humans;
• evaluate alternative placements for various land uses that might affect remediation/development costs; and
• meet with parties such as neighbors, investors, or agencies to explain health risk-related issues as part of an effort to build consensus or reduce fear or anger; this also may be known as risk communication.

2. Chemicals in drinking water – Chemicals are present in drinking water in several ways, including:

• As natural background components of the source surface water or groundwater,
• due to routine treatment of water for safety from pathogenic microbes (including disinfection byproducts),
• as a result of the composition of the distribution system and in-home plumbing, or
• as a result of unintended contamination of the source water.

Assistance available from an expert toxicologist could include:

• evaluation of potential health risk associated with the contamination;
• consideration of potential health risks from nonhousehold uses, such as irrigation;
• development of target levels for the chemical(s) in drinking water if there is no federal maximum contaminant level or other well-accepted criterion;
• evaluation of claims of adverse health effects as a result of the contamination, including in-depth consideration of available animal and or human studies about toxicity (toxicology and epidemiology literature); and
• presentations to customers, the public, and others.

3. Contamination in the home – Contamination inside the home (such as mold toxins, vapor intrusion, or lead) is about specific toxins, concentrations, and exposure conditions. However, contamination in the home may have the added dimension of greater perceived risk because a family’s home is “supposed” to be a safe refuge from the trials and tribulations of the larger world. In addition, children may be more susceptible to adverse health effects of contamination in the home due to a wide range of factors, both behavioral and biological. There may be added complexities, such as:

• the microbiological processes of living organisms in the home that may cause variable conditions and exposure over time;
• added dimensions to chemical or microbiological analytical methods, such as forms of lead in paint or various types of evidence related to molds like spores versus toxins;
• the impact on indoor air quality of periodic conditions such as HVAC cycles, open windows, humidity in air, moisture on surfaces or inside walls, and weather patterns; or
• the range of factors that can affect movement of chemicals, like volatile chemicals from the subsurface into indoor air or lead from paint to dust.

For example, lead may be present in deteriorating paint and dust in older homes but could also be present at elevated concentrations in drinking water in older homes with lead-based plumbing; outdoor soil (and therefore indoor dust) in areas that were formerly industrial; or in some cases in makeup, “natural” remedies, or jewelry or toys. An appropriate expert toxicologist can understand these complexities and help tease out significant contributors of lead from those less likely to be important overall. They also may understand the long history of childhood lead poisoning, including the waxing and waning of various sources of lead across time, geography, and socioeconomics, as well as the very long history of our still-improving understanding of the toxicity of lead to children and our refinement of screening blood lead levels (PbBs) as our understanding has grown.

4. Chemical accidents – Chemical accidents most often occur during transportation or in the workplace. Examples include a traffic or train accident that results in release of chemicals from containment, or unintended releases of chemicals normally present in the workplace. Evidence of the health consequences of these accidents can be immediate and/or possibly latent. An expert toxicologist can help sort between adverse effects that may be related to the release and adverse effects that are unlikely to have been caused by this exposure. Real-time data for exposure media (such as air) are not always available, in which case it is common to have another expert, someone who can model likely chemical concentrations in the exposure medium. An expert toxicologist can identify potential immediate and/or long-term adverse effects from accident-related releases, and evaluate the credibility and strength of claims in light of exposure concentration, route, and duration, as well as the toxicity of specific chemicals.

5. Workplace exposures – Chemicals are present in most workplaces, from printer ink and dust to chemicals pulled in by a poorly placed HVAC intake, from chemicals that are being produced to the chemical ingredients used to make that product. Exposures are most likely to be by inhalation and through the skin, and may be occasional or daily. Under some conditions, chemicals can be brought home (most commonly on clothing), resulting in exposure of family members. Chemicals also may cause complications with pregnancy or sperm production. An expert toxicologist can:

• assess potential relationships between chemicals, exposures, and claimed adverse effects;
• identify potential alternate causes of specific effects;
• sort strong claims from weaker ones; and
• provide in-depth evaluation of relevant literature in light of medical records.

6. Chemicals in food or feed – Chemicals can be present in food or animal feed as a result of intentional introduction (such as preservatives), environmental contamination or criminal activities (tampering or terrorism). For example, the presence of sufficient levels of aflatoxins (a mycotoxin that can occur naturally in certain storage conditions) in animal feed can sicken or even kill the animals. An expert toxicologist can help determine “safe” versus unsafe levels of contaminants in food or feed, as well as which claimed adverse effects are likely to have been associated with the specific chemicals and concentrations.

7. Chemicals in consumer products – All sorts of consumer products may result in exposures to chemicals, including,

• application of makeups, creams, and shampoos;
• off-gassing of chemicals from new cars, carpets, or furniture;
• household cleaners;
• paints;
• automobile-related fluids; and
• tobacco, marijuana, vaping liquid, and alcohol.

The increasing use of dietary and herbal supplements and essential oils opens a newer category of consumer products to which ever more people are exposed. For example, a person who, intentionally or unknowingly, consumes an herbal supplement in a “healthy” beverage product may have adverse effects from interactions of that herbal product with prescribed medications. An expert toxicologist can evaluate the facts of a case in the context of published scientific literature, medical records, and other records to determine whether, for example, an ingredient in the herbal product is likely to have interacted with routine medical treatment in a way that jeopardized patient welfare.

8. Regulatory criteria or cleanup goals – Regulatory criteria like state or federal drinking water standards or air criteria, or tolerances for pesticides in foods, are typically based, at least partially, on toxicity. In addition, there are risk-based (or partially risk-based) criteria to clean up contaminated media (such as soil, soil gas, and groundwater) at contaminated sites under the federal Comprehensive Environmental Response, Compensation, and Liability Act and the Resource Conservation and Recovery Act as well as in state programs, or as necessary to suit redevelopment goals. The two major factors that affect development of risk-based criteria or risk-based goals are exposure and toxicity. Toxicologists have a fundamentally necessary role in development of these numbers, or in challenging them. In addition, some (but not nearly all) risk assessors are toxicologists and in many contexts risk assessors play key roles in developing criteria. An expert toxicologist with experience in risk assessment and environmental issues can help you understand the bases of the criteria, and may identify alternative and equally credible bases for recalculating criteria, for instance by uncovering flaws in the studies or data sets on which criteria are based.

9. Adverse health effects of pharmaceuticals – Unfortunately, some adverse effects from medications cannot be observed until many people have used the medication over a long period of time. Others result from interactions of the pharmaceutical with foods or other medicines, potentially leading to traffic or workplace accidents. While these observations can lead to changes in labeled uses, they also can lead to class action (or individual) lawsuits. Often an expert toxicologist can shed light on key aspects of the occurrence of specific toxic endpoints, especially in light of pre-clinical animal studies.

When to Consider Including an Expert Toxicologist

Here are some indicators that an expert toxicologist may be able to add value:

1. The case hinges on causation related to chemical, pharmaceutical, or other (e.g., mycotoxin) toxicity.

2. There is a genuine issue of fact related to whether exposure occurred.

3. It is unclear whether the exposure was sufficient to cause the adverse effect(s) claimed.

4. There may be other potential sources of exposure to the same (or other) chemical(s).

5. The Plaintiff may have been somehow predisposed to these adverse effects or sensitive to this specific toxin.

6. The adverse effect may have been present prior to exposure.

7. Other factors, such as medical history, behavior, other chemical exposures, other disease processes, or other events have not been ruled out as potential causes of or contributors to the adverse effects.

8. Laboratory animal toxicity data and epidemiology and/or medical case data appear to lead to conflicting conclusions about toxicity.

Sometimes all that is needed is a clear and simple explanation of exposure concepts such as “the dose makes the poison.” In other situations, it may be important to rank potential sources of a single chemical or to explain that the adverse effect must follow the exposure by a certain amount of time. The facts related to these topics, and more, can be elucidated by the right expert toxicologist. In addition, of course, if the opposing attorney has disclosed an expert toxicologist, it may be a good idea for you to have one, too.

Other Disciplines

I have noticed that attorneys sometimes struggle with which of certain disciplines can best address key issues in a case. Other types of experts I have come across most often in conjunction with my testimony are: pharmacologists and pharmacists, industrial hygienists and safety professionals, and medical doctors.

These experts are not interchangeable with toxicologists; each of the disciplines is unique. Yet there are areas of overlap and areas of synergy. In some cases, only one type of expert may be necessary, but in many cases it may be optimal to include experts from more than one of these (or other related) disciplines. A potential testifying expert who has integrity will help you evaluate which disciplines may offer important contributions to development of your case; many experts will support your efforts to identify the most appropriate individual expert(s) to best serve your client, for example by developing a short list for your consideration or by referring you to other experts with whom they are familiar.

Conclusion

The right expert toxicologist can provide pivotal support to sellers, purchasers, and developers of contaminated property. They also can provide observations and analysis as well as reports and testimony in many types of cases. By offering science-based insights, an expert toxicologist can enhance strategies such as land use placement and settlement negotiations. An expert toxicologist can facilitate decision making by educating regulators, investors, and the triers of fact about the science underlying issues at hand.

Jenifer S. Heath, Ph.D., is a toxicologist with over 25 years of experience in her field. She has testified in depositions and at bench and jury trials. Dr. Heath helps her clients understand the potential adverse effects of chemical exposures, so her clients can make better informed decisions about litigation strategies, workplace safety, acquisitions, and site investigation and cleanup. She can be reached at JeniferHeath7@gmail.com or (303) 726-9601. www.HeathToxicology.expert.

The opinions expressed here do not represent those of Bloomberg Environment, which welcomes other points of view.