Concerns exist regarding a possible connection between exposure to the herbicide Roundup and multiple myeloma, a specific type of cancer. This article explores the current understanding from scientific research, legal proceedings, and regulatory assessments.
Understanding Multiple Myeloma and Roundup
Multiple myeloma is a cancer originating in plasma cells, a type of white blood cell in the bone marrow. Normally, plasma cells produce antibodies to fight infections. In multiple myeloma, cancerous plasma cells multiply uncontrollably, crowding out healthy blood-forming cells and leading to complications.
Roundup is a widely used herbicide. Its primary active ingredient, glyphosate, inhibits an enzyme pathway essential for plant growth. Glyphosate is often formulated with surfactants to enhance penetration into plants.
Scientific Investigations and Findings
Scientific research explores the potential link between glyphosate and various cancers, including multiple myeloma. Epidemiological studies investigate patterns and causes of diseases in populations, while toxicology research examines the adverse effects of chemical substances on living organisms. These studies aim to determine if exposure to glyphosate is associated with an increased risk of developing specific cancers. Some research has suggested a possible association between glyphosate exposure and certain cancers, though findings specifically on multiple myeloma have varied.
Establishing a definitive causal link in scientific research is complex due to various factors. Challenges include accounting for confounding variables, which are other factors that could influence cancer development, and limitations in study design that make it difficult to isolate the effect of a single chemical. The International Agency for Research on Cancer (IARC), part of the World Health Organization, classified glyphosate as “probably carcinogenic to humans” (Group 2A) in 2015. This classification was based on “limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma” and “sufficient evidence of carcinogenicity in experimental animals.” While multiple myeloma is a distinct cancer, it falls under the broader category of hematological malignancies, which includes lymphomas.
Further scientific research details specific findings. Epidemiological studies examine disease patterns, while toxicology research investigates chemical effects on living organisms. These studies aim to determine if glyphosate exposure increases cancer risk. Some epidemiological studies investigate associations between glyphosate exposure and lymphohematopoietic cancers, including non-Hodgkin lymphoma (NHL) and multiple myeloma. A 2016 meta-analysis found a marginally significant association between glyphosate exposure and multiple myeloma. However, another meta-analysis on occupational exposure found no increased risk for either NHL or multiple myeloma.
The U.S. Agricultural Health Study (AHS) found no association between glyphosate and NHL, even among highly exposed participants. A re-analysis of AHS data also found no convincing evidence linking multiple myeloma risk to glyphosate use. These varying results highlight challenges in establishing causation, as factors like study design and confounding by other pesticide exposures can influence findings. The IARC review also noted positive findings for multiple myeloma in three studies. Subsequent animal studies suggest glyphosate exposure could induce biochemical changes relevant to blood cancers like multiple myeloma.
Legal Proceedings and Outcomes
The question of whether Roundup causes cancer has been central to numerous lawsuits filed against Bayer, which acquired Monsanto, the original producer of Roundup. These legal actions often allege that exposure to Roundup led to the development of cancers, primarily non-Hodgkin lymphoma, and that Monsanto failed to adequately warn consumers about the risks. While many cases focused on NHL, some legal proceedings have also touched upon multiple myeloma as a potential outcome.
Several high-profile jury verdicts have found in favor of plaintiffs, with juries determining that Roundup contributed to their cancer. For instance, in 2018, a California jury awarded Dewayne Johnson, a former school groundskeeper, $289 million, later reduced, after finding that Roundup caused his non-Hodgkin lymphoma and that Monsanto acted with malice. This verdict was a significant moment, as it was the first case to go to trial alleging a direct link between Roundup and cancer.
Subsequent trials also resulted in large verdicts against Bayer. In 2019, a jury awarded Edwin Hardeman $80 million, later reduced, after concluding that Roundup was a substantial factor in his NHL. Another 2019 case involving Alva and Alberta Pilliod, a couple who both developed NHL after using Roundup for decades, resulted in a $2.055 billion verdict, later reduced on appeal. These verdicts often cited Monsanto’s alleged failure to warn users about the product’s risks. Despite appealing these verdicts, Bayer ultimately sought to resolve a large portion of the outstanding claims. In 2020, Bayer announced a settlement program to resolve approximately 100,000 Roundup lawsuits for an estimated $10.9 billion.
It is important to note that legal outcomes are based on different standards of proof than scientific certainty, often relying on a “more likely than not” standard rather than absolute scientific consensus. These settlements and verdicts reflect jury decisions or negotiated agreements rather than definitive scientific conclusions on causation.
Regulatory Agency Assessments
Governmental regulatory bodies worldwide assess glyphosate’s safety, often reaching different conclusions than some scientific bodies or legal rulings. These agencies review extensive data, including industry and independent research, to inform product registration.
The U.S. Environmental Protection Agency (EPA) consistently states glyphosate is “not likely to be carcinogenic to humans” when used as directed. Their 2020 assessment reaffirmed no human health risks from current registered uses, contrasting with IARC’s classification. Similarly, the European Food Safety Authority (EFSA) and European Chemicals Agency (ECHA) concluded glyphosate is not carcinogenic. EFSA’s 2023 assessment found no evidence of carcinogenicity, genotoxicity, or reproductive toxicity. These agencies base assessments on extensive scientific data and risk assessments, considering real-world exposure.
Regulatory conclusions often differ from scientific bodies or legal judgments due to differing mandates. Regulatory agencies focus on risk assessment for approved uses, while IARC identifies substances that could potentially cause cancer. This highlights the complexity of evaluating chemical health risks.
Navigating Current Information and Exposure Concerns
Information on Roundup, glyphosate, and multiple myeloma is complex, with differing perspectives from scientific research, legal proceedings, and regulatory assessments. While some studies and legal verdicts suggest an association, major regulatory bodies maintain glyphosate is not likely carcinogenic under approved use. Research continues to provide clarity.
For those concerned about herbicide exposure, follow product label instructions for safe handling and application. Use personal protective equipment like gloves and eyewear to minimize skin contact and inhalation. Consider alternative weed control methods like manual weeding or mulching to reduce reliance on chemical herbicides. For health concerns related to chemical exposure or multiple myeloma, consult a healthcare professional for personalized guidance and information.