Top 9 Mass Torts to Watch 2025

Camp Lejeune Water Contamination

The largest Marine Corps base on the East Coast, Camp Lejeune has provided housing and workspaces for thousands of servicemembers, their families, and civilian workers for decades. Between 1953 and 1987, many of these people drank, cooked with, and bathed in water contaminated with volatile organic compounds (VOCs).

These chemicals, including perchloroethylene (PCE), trichloroethylene (TCE), benzene, and vinyl chloride, have been linked to serious illnesses including cancers, leukemia, birth defects, and Parkinson’s disease.

Findings

The CDC’s Agency for Toxic Substances and Disease Registry connects the Camp Lejeune water contamination with various industrial spills, leaking underground storage tanks, and nearby dry cleaners’ contamination.

The CDC identified four VOCs in the Camp Lejeune water supply:

• PCE
• TCE
• Benzene
• Vinyl chloride

Exposure to any one of the four can cause damage to the human body, especially if exposure is prolonged. TCE, for example, is a carcinogen whether ingested, inhaled, or absorbed through the skin. It can also cause damage to the nervous system, kidney, liver, and immune system, as well as birth defects.

Camp Lejeune Justice Act

On August 10, 2022, President Biden signed the Camp Lejeune Justice Act (CLJA). The Act gave potential plaintiffs two years from the date of its enactment to file suit in the U.S. District Court of North Carolina. The government allotted $22 billion to cover Camp Lejeune settlements.

Before filing suit in North Carolina, injured plaintiffs must submit an administrative claim with the Department of the Navy, disclosing key facts including the dates of exposure, medical diagnoses and treatments, and financial or mental impacts the plaintiff suffered. Damages are offset by any previously paid disability claims.

Litigation Status

In 2023, over 1400 CLJA complaints were filed in the Eastern District of North Carolina. By December 18, 2023, 14 of these cases had been dismissed and six settlements had been reached. These settlements included:

• $250,000 for Parkinson’s disease
• $300,000 for non-Hodgkin’s lymphoma
• $300,000 each for two cases of leukemia
• $150,000 for one case of leukemia
• $150,000 for one case of bladder cancer

By some estimates, only about 15 percent of filed claims are eligible for early settlement. The remaining 85 percent may need to go through the court system to reach a resolution.

In early February 2024, the court ruled that the CLJA does not create a right to a jury trial for plaintiffs seeking relief under the Act.

Expert Witness Opportunities

As the Camp Lejeune cases begin, expert witnesses in toxicology, oncology, and related medical fields will likely be in high demand. Experts may be asked to opine on the scope of the water contamination and its risks and complications.

Toxicologists will be asked to opine on current medical literature and personal experiences treating the results of VOC contamination, as well as causal links between VOC exposure and various conditions. Physicians may be asked to review and interpret individual plaintiffs’ medical records and shed additional light on causation.

Claims under the CLJA can be denied for lack of proper evidence proving a qualifying medical condition exists. Expert medical testimony is essential to proving many of these claims.

For more information click here to watch Expert Institute’s Dr. Wendy Ketner and Ricky Siddiqui, MPH along with John Romano of Romano Law Group discuss the growing litigation surrounding Camp Lejeune.

Related Research Guides and Resources

• RESEARCH: Camp Lejeune Water Contamination: Medical Conditions Associated with Exposure
• READ: Contaminated Water at Marine Corps Base Camp Lejeune Causes Health Issues
• READ: Navigating Camp Lejeune Litigation: 5 Things Attorneys Need to Know
• WATCH: [Webinar] Camp Lejeune: Beyond Presumptive Diagnoses
• READ: Camp Lejeune Water Contamination Lawsuit: Litigation Guide

Hair Relaxer-Related Cancers

Hair relaxers use various chemicals to straighten and soften hair by altering proteins found in the hair shaft. A number of consumer hair straightening products, including shampoos, conditioners, sprays, gels, moisturizers, and treatments contain these chemicals.

Studies of hair relaxers increasingly show a connection between the most common chemicals used in hair relaxers and adverse health effects, including an increased risk of uterine fibroids.

Findings

A class of chemicals called Endocrine Disrupting Chemicals (EDCs) are so named because they affect the body’s hormonal systems. As these chemicals mimic or disrupt the body’s hormonal processes, they can cause developmental, reproductive, neurological, immunological, and other issues.

Certain EDCs are present in hair-relaxing products. Research indicates a link between prolonged exposure to these chemicals - such as by using hair relaxers regularly for many years - and the development of fibroids, endometriosis, or ovarian, uterine, or endometrial cancers. Other risk factors for these conditions are also widespread, however, making it difficult to identify the EDCs in hair relaxers as the primary or sole cause of any of these conditions.

Litigation Status

In fall 2022, a plaintiff in Missouri alleged that L’Oreal’s hair straightening products caused her uterine cancer. The suit also alleged that L’Oreal knew about the connection between the EDCs in their hair relaxers and cases of cancer since 2015 but concealed this information from the public. A related case filed in Illinois sought certification as a class action incorporating women who developed uterine cancer after using various L’Oreal hair relaxing products.

At the end of 2022, only about 150 pending cases regarding cancers related to hair relaxer use had been filed nationwide. By January 2024, that number had grown to over 8,000 cases. The cases were consolidated into an MDL in the Northern District of Illinois in early 2023. The plaintiffs propose to submit a bellwether trial list in February 2024, focusing on cases of ovarian, endometrial, and uterine cancers allegedly linked to the use of hair relaxers.

Expert Witness Opportunities

Toxicologists have a role to play in litigation related to the health effects of exposure to EDCs in hair relaxers. As expert witnesses, toxicologists can discuss the potential risks and complications of exposure to EDCs, discuss the literature surrounding this topic, and discuss any personal experiences treating the effects of EDC exposure.

Because the hair relaxer cases focus on cancers of the ovaries, endometrium, and uterus, as well as conditions like uterine fibroids and endometriosis, experts in gynecology can opine on the etiology, risk factors, and management of these conditions. Oncologists who specialize in the treatment of these cancers may also be asked for weigh-in.

Related Research Guides and Resources

• READ: L’Oreal Hair Straightening Product Lawsuit May Be First of Many

Access the latest research on the chemicals found in hair straightening products, consult our team of physicians to pinpoint causation and liability, and connect with world-class experts to understand the scope of potential damages here.

Hernia Mesh Complications

A hernia occurs when part of an internal organ becomes displaced, pushing through a bodily wall that ordinarily contains it. Common hernias involve a part of the intestine pushing through a weak point in the abdominal wall. Other types of hernias can also occur. Hernias that are not repaired can worsen, as stress on the abdominal wall continues to weaken the tissues.

Findings

Various techniques and tools have been developed to repair hernias. Laparoscopic ventral hernia repair (LVHR) uses laparoscopy to repair incisional hernias and other types of ventral abdominal hernias. Robotic hernia repair has also been deployed but remains expensive, often requiring lengthy operation time and associated risks to the patient.

During a hernia repair, a surgeon may install a hernia mesh product. The mesh is intended to reinforce the abdominal wall to prevent a hernia from returning or worsening. However, rising rates of side effects including bowel obstruction and organ perforation have led to a corresponding rise in lawsuits related to hernia mesh. Plaintiffs allege that the mesh causes additional health problems, often requiring surgery to correct and leaving patients with permanent injuries and that Bard’s failure to warn about the risks of using hernia mesh is directly connected to these injuries.

Litigation Status

Over 50,000 lawsuits have been filed in recent years related to hernia mesh products. As of January 17, 2024, the Ohio-based MDL against hernia mesh producer C.R. Bard contained 20,973 lawsuits. Plans for a fourth bellwether trial against Bard in the MDL were scrapped in February 2024 after the judge decided a fourth trial would not provide sufficient additional information to justify the effort.

Bard’s track record by the end of 2023 consisted of one win in the Ohio MDL, two losses, and one loss in a court in Rhode Island. Verdicts ranged from $250,000 to $4.8 million, the latter occurring in the Rhode Island case.

Expert Witness Opportunities

In hernia mesh cases, general surgeons play a key role as expert witnesses. General surgeons can discuss the indications for laparoscopic hernia repair, the risks and complications of such procedures, the available literature on these topics, and their personal experiences performing laparoscopic procedures and mesh installation.

Related Resources

• READ: Plaintiffs Win Second Hernia Mesh Bellwether Trial

Paragard IUD Complications

The Paragard IUD is a non-hormonal birth control device first approved by the FDA in 1984. The IUD’s coils release a small amount of copper particles, which cause an inflammatory reaction that prevents entering sperm from reaching an egg.

The Paragard is marketed as non-hormonal, lasting up to ten years, and easy for a doctor to remove simply by pulling the cord attached to the device. When the Paragard IUD is removed, the plastic arms at the top of the device are supposed to flex upward to allow it to travel easily through the cervix and out of the body.

However, Paragard IUD lawsuits allege that the plastic arms can become rigid over time, breaking when the device is removed. Sharp plastic pieces can become lodged in the uterus, requiring surgical removal or causing ongoing or even permanent complications.

Findings

Injuries and complications connected to the Paragard IUD include:

• Cervical or uterine perforation
• IUD migration within the body
• Inflammatory or allergic reactions caused when pieces of the IUD remain inside the body after removal
• IUD pieces become lodged in organs or lost inside the body
• Infertility
• Infections
• Pain and scarring
• Additional surgeries required to remove broken IUD pieces or treat complications related to the IUD.

Litigation Status

In 2021, the JPML transferred 49 cases regarding broken Paragard IUDs to the U.S. District Court for the Northern District of Georgia. By early 2024, 2,444 lawsuits were included in the MDL.

In January 2024, a case filed in New York provided an example of the type of cases appearing in the Paragard MDL. In the New York case, the plaintiff alleged that the device broke during a removal appointment on May 3, 2022. The plaintiff needed another procedure to remove the broken pieces in January 2023.

The first trial date in the Paragard IUD MDL is currently scheduled for October 2024.

Expert Witness Opportunities

OB-GYNs will likely be called upon in the Paragard case to discuss the use and placement of IUDs as well as their removal. They may be asked to opine on existing literature and their own experiences in removing patients’ Paragard IUDs.

Literature on how to manage fractured IUDs has been published for over ten years. Experts may be asked to review many published articles and provide an overview of this research, opining on how it relates to the responsibilities of Teva, Paragard’s manufacturer, in warning patients and physicians about breakage.

Related Research Guides and Resources

• READ: In re: Paragard IUD Products Liability Litigation
• READ: Drugwatch Paragard Lawsuit Update February 2024
• RESEARCH: Controversies in Family Planning: How to Manage a Fractured IUD
• RESEARCH: Fractured Copper Intrauterine Device (IUD) Retained in the Uterine Wall Leading to Hysterectomy: A Case Report
• RESEARCH: Trends in copper versus hormonal intrauterine device breakage reporting within the United States’ Food and Drug Administration Adverse Event Reporting System

Paraquat-Related Parkinson’s Disease

Paraquat is the generic name of Gramoxone, manufactured by Syngenta for use as a pesticide. The use of paraquat is banned in the United Kingdom, Switzerland, China, and several other countries due to extreme toxicity. While the pesticide remains legal in the United States, a rising number of cases are alleging that exposure to paraquat is linked to Parkinson’s disease, a progressive neurological disease.

These cases have been filed against Syngenta, which manufactures paraquat, and Chevron, which distributed paraquat in the US between 1966 and 1986.

Defendants allege that no scientific evidence supports a causal link between paraquat exposure and Parkinson’s disease; plaintiffs allege that defendants knew or should have known paraquat exposure could lead to neurological injuries. They also allege that defendants failed to warn of the risks of developing neurological injuries, including Parkinson’s.

Findings

Paraquat is a “restricted use” chemical in the United States, which means it cannot be sold to the general public. Only certain licensed agricultural parties can purchase or use it. However, neighbors to agricultural setups that use paraquat can also experience the effects of exposure from drift, overspray, or runoff.

Short-term symptoms of paraquat exposure include mouth and throat irritation and abdominal pain. In addition to Parkinson’s disease, long-term exposure is linked to conditions like liver and kidney failure, weakness, seizures, pulmonary fibrosis and edema, and increased heart rate. There is currently no antidote for paraquat poisoning.

On its website, the Parkinson’s Foundation acknowledges that many of the causes of Parkinson’s disease remain unknown. Yet the foundation also states that there is “a strong link” between exposure to pesticides and Parkinson’s disease. In 2021, the Parkinson’s Foundation urged the EPA to cancel its approval of the use of paraquat in the United States.

Litigation Status

In 2017, Syngenta and Chevron settled several lawsuits for a combined $187.5 million, brought by plaintiffs with Parkinson’s disease. As of early 2021, over 300 lawsuits alleging a link between paraquat exposure and Parkinson’s disease had been filed in the United States. The cases were consolidated into an MDL in 2021.

By February 2024, there were 5,077 cases pending in the Paraquat MDL. A January 2024 filing provides an example: In that case, the plaintiff claimed that the defendants’ failures to provide adequate warnings led to the plaintiff’s direct exposure to paraquat while working as a farmwork and herbicide applicator from 1978 to 2004. The plaintiff was diagnosed with Parkinson’s disease around 2014.

Expert Witness Opportunities

Toxicologists will be essential to ongoing paraquat litigation, and several have already participated in Daubert hearings in the MDL. Toxicologists can discuss the literature on the effects of paraquat exposure and their own experience treating patients with Parkinson’s and other conditions who have been exposed to paraquat.

Related Research Guides and Resources

• READ: 'Burns me to a crisp': Farmers allege link between popular herbicide paraquat and Parkinson's disease
• READ: Update from our CSO: Pesticides, Paraquat and Parkinson’s

Roundup-Related Cancers

Roundup (glyphosate) is a commonly used pesticide in the United States. Thousands of lawsuits have linked exposure to Roundup to various cancers, including non-Hodgkin’s lymphoma.

Multidistrict litigation consolidated in the U.S. District Court for the Northern District of California is pending.

Findings

Links between glyphosate exposure and cancer have been studied for some time. Current research indicates that exposure to glyphosate increases the risk of developing non-Hodgkin’s lymphoma by 41 percent. Glyphosate exposure is linked to an increased risk of developing other forms of cancer as well.

Litigation Status

The JPML transferred the Roundup cases to the Northern District of California in October 2016. Since then, the number of cases in the MDL has continued to grow.

The MDL is not the only source of litigation against Monsanto alleging harm caused by exposure to Roundup. In February 2024, Cloud v. Monsanto began in Delaware Superior Court. The case was brought by the family of a South Carolina groundskeeper, who allege that the decedent’s non-Hodgkin’s lymphoma, which proved fatal, was caused by longtime exposure to glyphosate.

By late 2023, ten plaintiffs had secured verdicts in Roundup-related cases.

Expert Witness Opportunities

Toxicologists, epidemiologists, and oncologists all have roles to play in Roundup cancer cases. Toxicologists can describe the literature and their experiences, opining on the link between glyphosate exposure and the development of non-Hodgkin’s lymphoma and other cancers. Epidemiologists can discuss the rising rates of these cases and the impact the research has on what Monsanto and Bayer knew or should have known about the risks of glyphosate exposure. Oncologists can discuss specific aspects of cancer development and treatment.

Related Research Guides and Resources

• RESEARCH: In re: Roundup Products Liability Litigation (MDL No. 2741)
• RESEARCH: Glyphosate and cancer: The importance of the whole picture
• RESEARCH: Effects of glyphosate exposure on human health: insights from epidemiological and in vitro studies
• RESEARCH: The impact and toxicity of glyphosate and glyphosate-based herbicides on health and immunity

Depo-Provera and Meningioma

Since its release in the 1990s, Depo-Provera has been a popular form of birth control. Also known as “the birth control shot,” Depo-Provera consists of an injection of synthetic progesterone taken once every three months.

New evidence, however, links Depo-Provera use to the development of meningiomas, a family of brain tumors.

Findings

A recent study of women who used Depo-Provera for birth control and similarly-situated women who did not revealed that the first group faces a significantly higher risk of meningioma, a form of brain tumor. The risk is highest in those who took Depo-Provera for more than one year.

Meningiomas are the most common form of brain tumor. The subtype of meningioma one has is determined by the tumor’s location within the skull. While most meningioma brain tumors are not cancerous, these tumors can still cause significant problems with pain, memory, sensory functions, and other brain functions.

Many meningioma brain tumors are inoperable due to their location within the skull. In other cases, a meningioma may be removed, but the risk of it returning, becoming cancerous, or both can be increased by the removal.

Litigation Status

Lawsuits are already being filed in several state courts, alleging a link between Depo-Provera use and a plaintiff’s resulting meningioma. Several cases have been filed in Philadelphia. These claims typically allege that the manufacturers of Depo-Provera failed to adequately warn of the risks of increased brain tumors from the use of medroxyprogesterone acetate - the synthetic hormone that is the active ingredient in Depo-Provera.

Some of these cases point to the fact that Pfizer manufactured a lower-dose version of Depo-Provera, while still failing to warn of the risks linking Depo-Provera use to meningioma. These cases allege that Pfizer knew of the risks, yet failed to warn.

Expert Witness Opportunities

Meningiomas are a class of tumors known to experience enhanced growth in the presence of progesterone. Explaining this link to a jury will likely be essential in discussing whether, what, and how Pfizer and other manufacturers understood the risk posed by Depo-Provera and meningioma. Endocrinologists, OB-GYNs, and similar physicians may be asked to make this connection clear to juries and judges.

Research and Resources

• READ: Lawsuit Information Center: Depo-Provera Lawsuits
• RESEARCH: Use of Progestogens and the Risk of Intracranial Meningioma: National Case-Control Study
• RESEARCH: Use of Progestogen Tied to Higher Chances of Benign Brain Tumor

Ozempic

Ozempic is the brand name for semaglutide, a medication also marketed under brand names including Wegovy, Rybelsus, Trulicity, and Mounjaro. Originally designed as a treatment for diabetes, Ozempic’s popularity skyrocketed in 2024 due to its promise as a weight loss drug.

However, Ozempic has also been linked to a number of health issues. Recent scientific studies have linked Ozempic use to an increased risk of gastroparesis. Additional lawsuits identify other medical conditions potentially linked to the drug as well.

Findings

To date, lawsuits and/or scientific studies have linked semaglutide use to the following medical conditions:

• Gastroparesis, or paralysis of the gastrointestinal tract,
• Other GI issues requiring hospitalization,
• Esophageal injuries, often requiring surgery to treat,
• Ileus or bowel obstruction,
• Gallbladder injuries, which can be exacerbated by surgery
• Deep vein thrombosis (DVT) and related injuries, which can be fatal,
• Pulmonary aspiration,
• Sudden vision loss or non-arteritic anterior ischemic optic neuropathy (NAION).

Litigation Status

Multi-district litigation regarding Ozempic-related injuries was filed in February 2024. In November 2024, a new master complaint was filed in the MDL, refining the claims against the defendants. Plaintiffs in an MDL can reference the master complaint when filing their own lawsuits detailing their individual claims.

Individual lawsuits continue to be filed against defendants in these cases, including Ozempic maker Novo Nordisk. In November 2024, one such case filed as part of the national MDL in Philadelphia came from a patient who alleges that Ozempic and Wegovy caused the patient to develop severe, chronic gastrointestinal conditions, including gastroparesis. The claim alleges that Novo Nordisk failed to warn users or healthcare providers about the drugs’ risk to GI health, which the companies should have known based on prior clinical studies and data.

As additional research clarifies the links between semaglutide use and various health conditions, more cases are likely to emerge. An increasing case volume may also be driven by continued interest in these medications as aids to weight loss.

Expert Witness Opportunities

Endocrinologists will play a key role in semaglutide cases. Discussing the research on the safety of semaglutide will raise questions about how the drug interacts with the functions of the pancreas and other key systems within the body.

In individual cases, experts will also need to clarify details about each patient’s particular injuries. Gastroenterologists will play a role in many cases linking semaglutide use to gastroparesis, for instance, while cases involving patients who developed NAION or similar eye injuries will call for expert testimony from ophthalmologists.

Research and Resources

• READ: Lawsuit Information Center: Ozempic Gastroparesis Lawsuits
• RESEARCH: Tendency of Semaglutide to Induce Gastroparesis: A Case Report
• RESEARCH: GLP-1 Agonists and Gastroparesis: Ozempic Initiation in a Case of Chronic GI Issues
• RESEARCH: Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide

Oxbryta and Sickle Cell Disease

Oxbryta (voxelotor) was released to the US market in 2019 to treat symptoms of sickle cell disease. However, mounting evidence indicates that Oxbryta actually aggravates some symptoms of the disease it is intended to treat.

FDA approved Oxbryta under the accelerated approval pathway in 2019. Accelerated approval allows for approval based on “intermediate” clinical endpoints that predict a drug’s benefits will outweigh its risks. However, in 2024 Pfizer withdrew Oxbryta from the market, stating that the company no longer believed its benefits outweighed its risks.

Findings

Patients using Oxbryta have reported increased cases of vaso-occlusive crises or VOCs. According to the FDA, “in postmarketing clinical trials of Oxbryta, Pfizer reported a higher rate of vaso-occlusive cases in patients with sickle cell disease receiving Oxbryta compared to placebo.” Patients receiving Oxbryta also experienced a higher death rate than patients in the control groups. Two real-world registry studies also showed a higher risk of VOCs in patients taking Oxbryta.

Vaso-occlusive crises can cause severe pain as sickled red blood cells block blood flow and oxygen delivery to tissues. If oxygen delivery is blocked long enough, the affected tissues can die, resulting in organ damage, necrosis, and the need for amputation or other surgeries to save the affect patient’s life.

Litigation Status

Oxbryta was voluntarily recalled by its manufacturer, Pfizer Inc., in September 2024. Pfizer announced it was taking Oxbryta off the market, ceasing distribution, and discontinuing all active clinical trials and expanded access programs for the medication. The EMA’s Committee for Medicinal Products for Human Use recommended halting marketing authorization for Oxbryta in Europe in November 2024.

As of November 2024, several lawsuits had been filed in California and other states. In the California case, a plaintiff claims that Oxbryta caused an increase in VOCs, including a stroke in September 2024. The lawsuit alleges that Pfizer knew Oxbryta could cause these adverse effects “for some time” and should have withdrawn the medication from the market sooner or never introduced it at all.

Expert Witness Opportunities

Sickle cell disease is less well-known than other medical conditions featuring in this year’s mass torts. Consequently, Oxbryta cases will rely heavily on expert witnesses who can make sickle cell disease and its risks easy for juries to understand. These cases will also likely require experts who can discuss the FDA’s accelerated approval program and Pfizer’s responsibilities pursuant to accelerated approval of its product.

Research and Resources

READ: Lawsuit Information Center: Oxbryta Lawsuits

READ: EMA recommends suspension of sickle cell disease medicine Oxbryta

READ: FDA is alerting patients and health care professionals about the voluntary withdrawal of Oxbryta from the market due to safety concerns