07
May
Literature Review Links Pesticide Exposure to Increased Risks of Multiple Myeloma, a Blood Cancer
(Beyond Pesticides, May 7, 2026) Adding to the wide body of science on pesticide-induced cancer, researchers from the Icahn School of Medicine at Mount Sinai’s Department of Hematology and Medical Oncology and Department of Environmental Medicine find that environmental and occupational exposures increase the risk of developing multiple myeloma (MM), a type of blood cancer. As published in Blood Reviews, the literature review highlights how exposure to contaminants, such as pesticides, dioxins, combustion byproducts, and ambient air pollution, can cause MM through mechanisms of oxidative stress, DNA damage, and aryl hydrocarbon receptor signaling, as well as influence disease biology through immune dysregulation.
“Earlier epidemiologic studies suggested associations between environmental exposures and disease risk, but few have used modern geospatial or exposomic [totality of environmental exposure relating to health effects] methods capable of capturing exposure complexity,†the authors write. They continue: “Advances in data integration, spatial modeling, and molecular profiling now make it possible to revisit these questions with greater precision and biological context. This review summarizes current evidence on environmental exposures in plasma cell disorders and frames a research agenda for integrating exposomic data to improve exposure resolution and evaluate plausible mechanisms in MM.â€
Background
Multiple myeloma is an incurable plasma cell cancer. The American Cancer Society estimates that in 2026 about “36,000 new cases will be diagnosed (20,150 in men and 15,850 in women)†and approximately “10,850 deaths are expected to occur (5,780 in men and 5,070 in women).†As the second most common hematologic cancer in the U.S., understanding the drivers of MM is important. The precursor states of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) also “arise from a complex interplay of genetic, immunologic, and environmental factors†that need to be considered.
In Blood, the official journal of the American Society of Hematology, research from 2009 was the first to show an association between pesticide exposure and an excess prevalence of MGUS. The study involving 678 individuals who apply pesticides, culled from a U.S. Agricultural Health Study of over 50,000 farmers, finds that exposure to certain pesticides doubles one’s risk of developing an abnormal blood condition (MGUS) as compared with individuals in the general population. The researchers also evaluate the potential association between MGUS prevalence and 50 specific pesticides for which usage data were known. Of the chemicals studied, a significantly increased risk of MGUS is observed among users of dieldrin (an insecticide), carbon-tetrachloride/carbon disulfide (a fumigant mixture), and chlorothalonil (a fungicide). The MGUS risk for these agents increases 5.6-fold, 3.9-fold, and 2.4-fold, respectively. (See more here.)
In previous Daily News, research in the journal Environmental Health Perspectives finds that long-term exposure to the insecticide permethrin and legacy organochlorine insecticides (aldrin, dieldrin, and lindane) increase the risk of developing MGUS, a blood disease that precedes multiple myeloma, with disproportionate risks to farmers and farmworkers. This study highlights the importance of understanding how pesticide use can increase the risk of latent diseases, which do not readily develop upon initial exposure. As the researchers state, “Our findings provide important insights regarding exposures to specific pesticides that may contribute to the excess of MM among farmers… [T]he continued widespread residential and other use of permethrin and environmental exposure to organochlorine insecticides due to legacy contamination…could have important public health implications for exposed individuals in the general population.â€
Another study published in Environment International finds higher rates of various cancers among agricultural workers, with multiple myeloma and melanoma (skin cancer) disproportionately impacting female farmers. Although research studies link cancer risk to genetic and external factors (e.g., cigarette smoke), there are increasing reports and scientific studies that pesticide exposure augments the risk of developing increasingly common cancers like melanoma and less common cancers like multiple myeloma. The study finds a total of 23,188 cancer cases in which melanoma of the skin and multiple myeloma instances are higher among women compared to the general population. In addition, the study finds elevated rates of prostate cancer among men compared to the general population. (See Daily News here.)
Literature Review Findings
In the current study, scientific literature was identified that evaluates environmental or contextual exposures in relation to MM, SMM, and/or MGUS. As a result, the authors find that the most consistently implicated exposures include dioxins, particularly 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD is a component of Agent Orange, an herbicide used during the Vietnam War that is classified as a human carcinogen by the International Agency for Research on Cancer (IARC). (See here and here for additional coverage on Agent Orange and military exposure.) Dioxins are also found as contaminants in the wood preservative pentachlorophenol used on utility poles, railroad ties, and pilings.
One study of a U.S. veteran MGUS cohort finds high TCDD exposure predicted faster progression to MM while a meta-analysis of TCDD and cancer mortality also shows increased MM risk. “Although TCDD has been banned in the United States for decades [as a result of the banning of 2,4,5-T], dioxins persist in the environment and are still emitted from industrial combustion, waste incineration, and related processes,†the authors point out. They continue, “Low-level exposure is widespread, primarily through the food chain via bio-accumulation in animal fats.â€
Research on occupational exposure for agricultural workers documents that pesticide exposure is associated with higher risk of MM. One study shows that pesticide exposure for ten years or more is linked to increased MM risk, while another Canadian population-based study of lifetime uses of carbamates, phenoxy herbicides, and multiple organochlorines is associated with elevated MM odds, particularly with carbaryl and captan exposure. “The North American Pooled Project reinforced these findings, reporting increased MM risk with use of carbaryl, captan, and dichlorodiphenyltrichloroethane (DDT), with clear dose–response relationships for cumulative exposure,†the researchers state.
The persistence and ongoing threats from legacy chemicals no longer actively in use, such as DDT, shows that the health and environmental risks of pesticides is a complex issue that does not end when individual chemicals are banned. These compounds adversely impact soil, sediments, and food chains longer after use, bioaccumulating throughout the food web and impacting future generations. (See more here.) In summary, the authors state, “Together, these observations raise the possibility that environmental exposures may influence MM not only through direct cellular damage, but also through hematopoietic clonal selection and marrow microenvironmental changes.â€
Previous Research
Additional scientific literature connects pesticide exposure to cancer incidence through mechanisms of oxidative stress and DNA damage. In a research article in Environmental Sciences Europe last year regarding the weed killer glyphosate, a researcher finds that the chemical persists in bones before reentering the bloodstream. The mechanisms in which this herbicide interacts with important cells for development, called hematopoietic stem cells (HSCs), and breaks and rearranges DNA offers an explanation for the heightened risk of cancer, specifically blood cancers like non-Hodgkin lymphoma (NHL), myeloma, and leukemia. This review focuses on understanding the mechanisms by which exposure to glyphosate contributes to the risk of hematopoietic cancers based on the current scientific literature. In identifying glyphosate as a genotoxic threat that lingers in bones, the study’s author, Charles Benbrook, PhD, is able to connect the compound with heightened blood cancer risks. (See Daily News here.)
A literature review of studies published between 2011 to 2020, as analyzed by the Federal University of Goias, Brazil, finds occupational exposure to agricultural pesticides increases the risk for 45 different types of cancer, with multiple myeloma, bladder cancer, non-Hodgkin lymphoma, and prostate cancer as the most prevalent forms of cancer. This study highlights the significant role that long-term research plays in identifying potential health concerns surrounding registered pesticides. (See Daily News here.)
More recent research, as shared in an article in The New Lede, entitled Seeking answers to a cancer crisis in Iowa, researchers question if agriculture is to blame, documents case studies of cancer diagnoses linked to chemical-intensive agriculture. The New Lede article captures the experiences of individuals in Iowa on “the rising rates of cancer plaguing the state,†with a call for an investigation of “potential environmental causes for what some call a cancer ‘crisis.’†Through both personal stories of cancer patients with no other known risk factors aside from agricultural exposure, as well as comments from community members a listening session held in Indianola, Iowa, the article highlights not only the pervasiveness of cancer but the heightened risks of living in areas heavily farmed with toxic chemicals. (See more here.)
Moving Forward
With cancer as one of the leading causes of death across the globe, studies associating pesticide exposure with cancer offer insight into the underlying mechanisms that cause the disease. It is essential to recognize the health implications of pesticide use and exposure on humans, particularly if pesticides increase chronic disease risk. Thus, Beyond Pesticides tracks the most recent news and studies related to pesticides through the Daily News Blog and Pesticide-Induced Diseases Database (PIDD). This database supports the clear need for strategic action to shift away from pesticide dependency.
One way to reduce human and environmental contamination from pesticides is buying, growing, and supporting organic. Numerous studies find that levels of pesticide metabolites within the human body are lower after switching to an all-organic diet. For more information on how organic is the right choice for consumers, see Health Benefits of Organic Agriculture. Take action: >> Ask the U.S. Senate to hold the line and reject the House Farm Bill, pass a clean bill that extends the current law, and regroup to build a sustainable agricultural sector that respects farmers, farmworkers, consumers, and the environment.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
del Rosal, M. et al. (2026) Environmental exposures and multiple myeloma risk: A contemporary review of epidemiologic associations and mechanistic plausibility, Blood Reviews. Available at: https://www.sciencedirect.com/science/article/pii/S0268960X26000317.
