{"id":37793,"date":"2025-02-27T00:01:52","date_gmt":"2025-02-27T05:01:52","guid":{"rendered":"https:\/\/beyondpesticides.org\/dailynewsblog\/?p=37793"},"modified":"2025-02-26T10:34:29","modified_gmt":"2025-02-26T15:34:29","slug":"glyphosate-weed-killer-contaminates-stem-cells-is-linked-to-blood-cancers-and-dna-damage-study-finds","status":"publish","type":"post","link":"https:\/\/beyondpesticides.org\/dailynewsblog\/2025\/02\/glyphosate-weed-killer-contaminates-stem-cells-is-linked-to-blood-cancers-and-dna-damage-study-finds\/","title":{"rendered":"Glyphosate Weed Killer Contaminates Stem Cells, Is Linked to Blood Cancers and DNA Damage, Study Finds"},"content":{"rendered":"

(Beyond Pesticides<\/em>, February 27, 2025) In analyzing current scientific literature and data on glyphosate-based herbicides (GBHs), a research article in Environmental Sciences Europe<\/em><\/a> finds that glyphosate<\/a> (GLY) persists in bones before reentering the bloodstream. The mechanisms in which GLY interacts with important cells for development, called hematopoietic stem cells (HSCs), and breaks and rearranges DNA<\/a> offer a possible explanation for the heightened risk of cancer<\/a>, specifically blood cancers like non-Hodgkin lymphoma (NHL), myeloma, and leukemia.<\/p>\n

\u201cExisting data on GLY\/GBH metabolism and genotoxicity provide critical insights into how exposures may be contributing to blood cancers,\u201d according to the study\u2019s author, Charles Benbrook, PhD. Dr. Benbrook continues: \u201cA significant portion of GLY reaching blood moves quickly into bone marrow and then bone, where it can bioaccumulate and persist… Data reviewed herein suggest that a portion of the GLY excreted by most people on a daily basis can be traced to the shedding of calcium-GLY complexes in bone back into the blood supply.\u201d<\/p>\n

This allows for near-constant contact between glyphosate molecules and hematopoietic stem cells, which are immature cells that can develop into any type of blood cell. Mutations in hematopoietic stem cells can cause blood cancers to emerge. Those at disproportionate risk<\/a> with GLY exposure, such as farmworkers<\/a> and pesticide applicators, likely have “hundreds of million, if not billions of GLY molecules in bone marrow for every hematopoietic stem cell,\u201d Dr. Benbrook states, highlighting the connection between GLY exposure and blood cancer risk.<\/p>\n

There is a wide body of science on pesticide-induced diseases<\/a>, with a multitude of studies focusing on GLY\/GBH exposure. (See more coverage from Beyond Pesticides here<\/a> and stay tuned for an in-depth analysis on recent research<\/a> connecting agrichemical mixtures and pediatric cancer.) These studies confirm that products containing glyphosate can trigger oxidative stress<\/a>, impair DNA, and increase cancer risk. (See previous Beyond Pesticides coverage here<\/a>, here<\/a>, here<\/a>, and here<\/a>.) The mechanisms behind these effects are not fully understood, but research, including Dr. Benbrook\u2019s article, showcases potential pathophysiologic bases (combining pathology<\/a> and physiology<\/a>) for better understanding the extent to which GLY impacts organisms down to the molecular level.<\/p>\n

History of Glyphosate<\/em><\/p>\n

As the review highlights, GLY is \u201cthe most heavily applied pesticide ever brought to market… No other pesticide in history has come close to such extensive worldwide use.\u201d The widespread utilization of this pesticide endangers not only pesticide applicators, but farmers, farmworkers, and their families<\/a>, those who live near agricultural land, and the general public that consumes food and beverages containing GLY residues.<\/p>\n

With its wide use, glyphosate exposure raises concern for all organisms and the environment. As Dr. Benbrook says, \u201cExcessive reliance on GLY has brought on several problems. These include the emergence and spread of resistant weeds<\/a>, loss of terrestrial biodiversity<\/a>, water contamination<\/a>, and declining soil health<\/a>.\u201d<\/p>\n

GLY exposure, and subsequent research, span many decades. The debate over the carcinogenicity of GLY has persisted for over 40 years, but regulatory agencies such as the U.S. Environmental Protection Agency (EPA) and the European Food Safety Authority (EFSA) \u201care among several regulatory authorities that have concluded that dietary exposure to active substance glyphosate is unlikely to pose cancer risk.\u201d Dr. Benbrook continues in saying, \u201cBut substantial data show that applicators of formulated glyphosate-based herbicides are often exposed dermally to much higher levels of GLY and that repeated dermal exposure episodes over many years heightens cancer risk.\u201d (See studies here<\/a>, here<\/a>, here<\/a>, and here<\/a>.)<\/p>\n

There are many regulatory deficiencies<\/a>, and dermal exposure to GLY is just one of them. As the review shares: \u201cThe Office of Pesticide Programs (OPP) in the U.S. EPA has largely ignored dermal exposures to GBHs in the still ongoing reregistration review cycle… [T]he OPP concluded that applicator and occupational exposure and risk assessments were not necessary. This OPP judgement, and the 0.1 mg\/kg occupational exposure threshold, are not based on studies capable of detecting the impacts of GLY\/GBH on hematopoietic stem cells.\u201d<\/p>\n

In a previous article<\/a> by Dr. Benbrook, he analyzes independent research reviewed by the International Agency for Research on Cancer (IARC<\/a>) of the World Health Organization (WHO) and reports \u201c~ 80% produced some evidence supportive of an association between GLY\/GBHs and DNA damage<\/a>.\u201d Despite this finding, EPA has continued its registration of GLY. \u201cThe OPP relied on mostly negative genotox\/mechanistic studies on glyphosate technical carried out by GBH registrants, and the agency dismissed or ignored multiple in vivo studies reporting evidence of genotoxicity and\/or oxidative stress following exposure to GBHs, including some studies in exposed human populations,\u201d Dr. Benbrook notes.<\/p>\n

Additional independent research (see here<\/a> and here<\/a>) of GBHs highlights evidence linking GBH exposures to cancer outcomes. More specifically, as Dr. Benbrook states, \u201cPapers published since the completion of the EPA and IARC reviews have enhanced the weight-of-evidence supporting a linkage between GBH exposures and some hematopoietic cancers.\u201d (See studies here<\/a> and here<\/a>.)<\/p>\n

Review of Study Data<\/em><\/p>\n

To explore his hypotheses regarding how GLY storage occurs in bones and how the prolonged interaction with hematopoietic stem cells heightens the risk of blood cancers, Dr. Benbrook critiques animal bioassays and epidemiologic studies that \u201clink GLY\/GBH exposure to heightened risk of blood cancers, and possibly other pathologies.\u201d<\/p>\n

The research he reviews shows adverse impacts on both human and animal health, including non-Hodgkin lymphoma, leukemia, DNA damage, reduced birth weight, dysbiosis in gut microbiota, impaired development in children, and more. Additional areas of concern highlighted by studies involve surfactants in pesticide formulations, as well as the metabolites<\/a> (breakdown products) of GLY. The implications of these finding are enormous since many biomonitoring studies focused on GLY \u201cshow that a majority of people, usually 70\u201390% or more of individuals tested, have detectable levels of GLY and\/or its primary metabolite aminomethylphosphonic acid (AMPA) in their urine or blood,\u201d Dr. Benbrook shares. (See studies here<\/a>, here<\/a>, here<\/a>, here<\/a>, and here,<\/a> as well as previous Daily News<\/em> coverage on GLY contributing to body burden<\/a> here<\/a> and here<\/a>.)<\/p>\n

He continues: \u201c[D]ietary exposures and risk assessments should, but often do not, include data on levels of AMPA in food and beverages. This is because once sprayed on a food crop, the GLY in a GBH breaks down to AMPA incrementally over time. Many epidemiological studies<\/a> report stronger associations between AMPA levels in human biofluids and adverse health outcomes, compared to associations between GLY and the same adverse outcome.\u201d<\/p>\n

Dr. Benbrook also states: \u201c[T]he impact of GLY and AMPA on the etiology of cancer must be evaluated taking into account the impacts of other chemicals. Exposures to complex mixtures<\/a> can augment oxidative stress, disrupt the repair of damaged DNA, and trigger other adverse genetic and epigenetic effects that, in turn, alter the impacts of GLY and AMPA on cancer and other health outcomes. Moreover, such effects can occur at doses well-below current safety thresholds.\u201d<\/p>\n

Results noted in the review article include:<\/p>\n