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Environmental Research Jun 2024Glyphosate is the most widely used herbicide worldwide, both in domestic and industrial settings. Experimental research in animal models has demonstrated changes in...
BACKGROUND
Glyphosate is the most widely used herbicide worldwide, both in domestic and industrial settings. Experimental research in animal models has demonstrated changes in muscle physiology and reduced contractile strength associated with glyphosate exposure, while epidemiological studies have shown associations between glyphosate exposure and adverse health outcomes in critical biological systems affecting muscle function.
METHODS
This study used data from a nationally representative survey of the non-institutionalized U.S. general population (NHANES, n = 2132). Urine glyphosate concentrations were determined by ion chromatography with tandem mass spectrometry. Hand grip strength (HGS) was measured using a Takei Dynamometer, and relative strength estimated as the ratio between HGS in the dominant hand and the appendicular lean mass (ALM) to body mass index (ALMBMI) ratio. Low HGS and low relative HGS were defined as 1 sex-, age- and race-specific SD below the mean. Physical function limitations were identified as significant difficulty or incapacity in various activities.
RESULTS
In fully-adjusted models, the Mean Differences (MD) and 95% confidence intervals [95%CI] per doubling increase in glyphosate concentrations were -0.55 [-1.09, -0.01] kg for HGS in the dominant hand, and -0.90 [-1.58. -0.21] kg for HGS/ALMBMI. The Odds Ratios (OR) [95% CI] for low HGS, low relative HGS and functional limitations by glyphosate concentrations were 1.27 [1.03, 1.57] for low HGS; 1.43 [1.05; 1.94] for low relative HGS; 1.33 [1.08, 1.63] for stooping, crouching or kneeling difficulty; 1.17 [0.91, 1.50] for lifting or carrying items weighting up to 10 pounds difficulty; 1.21 [1.01, 1.40] for standing up from armless chair difficulty; and 1.47 [1.05, 2.29] for ascending ten steps without pause difficulty.
CONCLUSIONS
Glyphosate exposure may be a risk factor for decreased grip strength and increased physical functional limitations. More studies investigating the influence of this and other environmental pollutants on functional aging are needed.
Topics: Glyphosate; Glycine; Humans; Male; Middle Aged; Female; Aged; Herbicides; Hand Strength; Environmental Exposure; Nutrition Surveys
PubMed: 38452917
DOI: 10.1016/j.envres.2024.118547 -
FEMS Microbiology Ecology Jun 2023Pollinator decline is one of the gravest challenges facing the world today, and the overuse of pesticides may be among its causes. Here, we studied whether glyphosate,...
Pollinator decline is one of the gravest challenges facing the world today, and the overuse of pesticides may be among its causes. Here, we studied whether glyphosate, the world's most widely used pesticide, affects the bumblebee gut microbiota. We exposed the bumblebee diet to glyphosate and a glyphosate-based herbicide and quantified the microbiota community shifts using 16S rRNA gene sequencing. Furthermore, we estimated the potential sensitivity of bee gut microbes to glyphosate based on previously reported presence of target enzyme. Glyphosate increased, whereas the glyphosate-based herbicide decreased gut microbiota diversity, indicating that negative effects are attributable to co-formulants. Both glyphosate and the glyphosate-based herbicide treatments significantly decreased the relative abundance of potentially glyphosate-sensitive bacterial species Snodgrasella alvi. However, the relative abundance of potentially glyphosate-sensitive Candidatus Schmidhempelia genera increased in bumblebees treated with glyphosate. Overall, 50% of the bacterial genera detected in the bee gut microbiota were classified as potentially resistant to glyphosate, while 36% were classified as sensitive. Healthy core microbiota have been shown to protect bees from parasite infections, change metabolism, and decrease mortality. Thus, the heavy use of glyphosate-based herbicides may have implications on bees and ecosystems.
Topics: Bees; Animals; Gastrointestinal Microbiome; Herbicides; RNA, Ribosomal, 16S; Microbiota; Bacteria; Glyphosate
PubMed: 37316439
DOI: 10.1093/femsec/fiad065 -
The Yale Journal of Biology and Medicine Jun 2023Many chemicals and toxicants are released into our ecosystem and environment every day, which can cause harmful effects on human populations. Agricultural compounds are... (Review)
Review
Many chemicals and toxicants are released into our ecosystem and environment every day, which can cause harmful effects on human populations. Agricultural compounds are used in most crop production and have been shown to cause negative health impacts, including effects on reproduction and other pathologies. Although these chemicals can be helpful for pest and weed control, the compounds indirectly impact humans. Several compounds have been banned in the European Union but continue to be used in the United States. Recent work has shown most toxicants affect transgenerational generations more than the directly exposed generations through epigenetic inheritance. While some toxicants do not impact the directly exposed generation, the later generations that are transgenerational or ancestrally exposed suffer health impacts. Due to impacts to future generations, exposure becomes an environmental justice concern. The term "environmental justice" denotes the application of fair strategies when resolving unjust environmental contamination. Fair treatment means that no group should bear a disproportionate share of negative environmental consequences resulting from industrial, municipal, and commercial operations. This article illustrates how research on directly exposed generations is often prioritized over studies on transgenerational generations. However, research on the latter generations suggests the need to take environmental justice concerns seriously moving forward, as future generations could be unduly shouldering harms, while not enjoying benefits of production.
Topics: Humans; Epigenesis, Genetic; DNA Methylation; Ecosystem
PubMed: 37396986
DOI: 10.59249/FKWS5176 -
Gut Microbes Dec 2023Glyphosate, the active ingredient in the broad-spectrum herbicide Roundup, has been a topic of discussion for decades due to contradictory reports of the effect of... (Review)
Review
Glyphosate, the active ingredient in the broad-spectrum herbicide Roundup, has been a topic of discussion for decades due to contradictory reports of the effect of glyphosate on human health. Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) of the shikimic pathway producing aromatic amino acids in plants, a mechanism that suggests that the herbicide would not affect humans as this pathway is not found in mammals. However, numerous studies have implicated glyphosate exposure in the manifestation of a variety of disorders in the human body. This review specifically outlines the potential effect of glyphosate exposure on the composition and functionality of the gut microbiome. Evidence has been building behind the hypothesis that the composition of each individual gut microbiota significantly impacts health. For this reason, the potential of glyphosate to inhibit the growth of beneficial microbes in the gut or alter their functionality is an important topic that warrants further consideration.
Topics: Animals; Humans; Gastrointestinal Microbiome; Glycine; Herbicides; Mammals
PubMed: 38099711
DOI: 10.1080/19490976.2023.2263935 -
Chemosphere Oct 2023Glyphosate was classified as a probable human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC) partially due to strong mechanistic... (Review)
Review
Glyphosate was classified as a probable human carcinogen (Group 2A) by the International Agency for Research on Cancer (IARC) partially due to strong mechanistic evidence in 2015. Since then, numerous studies of glyphosate and its formulations (GBF) have emerged. These studies can be evaluated for cancer hazard identification with the newly described ten key characteristics (KC) of carcinogens approach. Our objective was to assess all in vivo, ex vivo, and in vitro mechanistic studies of human and experimental animals (mammals) that compared exposure to glyphosate/GBF with low/no exposure counterparts for evidence of the ten KCs. A protocol with our methods adhering to PRISMA guidelines was registered a priori (INPLASY202180045). Two blinded reviewers screened all in vivo, ex vivo, and in vitro studies of glyphosate/GBF exposure in humans/mammals reporting any KC-related outcome available in PubMed before August 2021. Studies that met inclusion criteria underwent data extraction conducted in duplicate for each KC outcome reported along with key aspects of internal/external validity, results, and reference information. These data were used to construct a matrix that was subsequently analyzed in the program R to conduct strength of evidence and quality assessments. Of the 2537 articles screened, 175 articles met inclusion criteria, from which we extracted >50,000 data points related to KC outcomes. Data analysis revealed strong evidence for KC2, KC4, KC5, KC6, KC8, limited evidence for KC1 and KC3, and inadequate evidence for KC7, KC9, and KC10. Notably, our in-depth quality analyses of genotoxicity (KC2) and endocrine disruption (KC8) revealed strong and consistent positive findings. For KC2, we found: 1) studies conducted in humans and human cells provided stronger positive evidence than counterpart animal models; 2) GBF elicited a stronger effect in both human and animal systems when compared to glyphosate alone; and 3) the highest quality studies in humans and human cells consistently revealed strong evidence of genotoxicity. Our analysis of KC8 indicated that glyphosate's ability to modulate hormone levels and estrogen receptor activity is sensitive to both exposure concentration and formulation. The modulations observed provide clear evidence that glyphosate interacts with receptors, alters receptor activation, and modulates the levels and effects of endogenous ligands (including hormones). Our findings strengthen the mechanistic evidence that glyphosate is a probable human carcinogen and provide biological plausibility for previously reported cancer associations in humans, such as non-Hodgkin lymphoma. We identified potential molecular interactions and subsequent key events that were used to generate a probable pathway to lymphomagenesis.
Topics: Animals; Humans; Carcinogens; Herbicides; Neoplasms; Lymphoma, Non-Hodgkin; Mammals; Glyphosate
PubMed: 37474029
DOI: 10.1016/j.chemosphere.2023.139572 -
BMC Plant Biology Feb 2024Symbiotic Methylobacterium comprise a significant portion of the phyllospheric microbiome, and are known to benefit host plant growth, development, and confer tolerance...
Symbiotic Methylobacterium comprise a significant portion of the phyllospheric microbiome, and are known to benefit host plant growth, development, and confer tolerance to stress factors. The near ubiquitous use of the broad-spectrum herbicide, glyphosate, in farming operations globally has necessitated a more expansive evaluation of the impacts of the agent itself and formulations containing glyphosate on important components of the plant phyllosphere, including Methylobacterium.This study provides an investigation of the sensitivity of 18 strains of Methylobacterium to glyphosate and two commercially available glyphosate-based herbicides (GBH). Nearly all strains of Methylobacterium showed signs of sensitivity to the popular GBH formulations WeatherMax® and Transorb® in a modified Kirby Bauer experiment. However, exposure to pure forms of glyphosate did not show a significant effect on growth for any strain in both the Kirby Bauer test and in liquid broth, until polysorbate-20 (Tween20) was added as a surfactant. Artificially increasing membrane permeability through the introduction of polysorbate-20 caused a 78-84% reduction in bacterial cell biomass relative to controls containing glyphosate or high levels of surfactant only (0-9% and 6-37% reduction respectively). Concentrations of glyphosate as low as 0.05% w/v (500 µg/L) from both commercial formulations tested, inhibited the culturability of Methylobacterium on fresh nutrient-rich medium.To better understand the compatibility of important phyllospheric bacteria with commercial glyphosate-based herbicides, this study endeavours to characterize sensitivity in multiple strains of Methylobacterium, and explore possible mechanisms by which toxicity may be induced.
Topics: Glyphosate; Herbicides; Glycine; Polysorbates; Surface-Active Agents
PubMed: 38369476
DOI: 10.1186/s12870-024-04818-x -
ACS Omega Feb 2024With a growing global population, agricultural scientists are focusing on crop production management and the creation of new strategies for a higher agricultural output.... (Review)
Review
With a growing global population, agricultural scientists are focusing on crop production management and the creation of new strategies for a higher agricultural output. However, the growth of undesirable plants besides the primary crop poses a significant challenge in agriculture, necessitating the massive application of herbicides to eradicate this problem. Several synthetic herbicides are widely utilized, with glyphosate emerging as a potential molecule for solving this emerging issue; however, it has several environmental and health consequences. Several weed species have evolved resistance to this herbicide, therefore lowering agricultural yield. The persistence of glyphosate residue in the environment, such as in water and soil systems, is due to the misuse of glyphosate in agricultural regions, which causes its percolation into groundwater via the vertical soil profile. As a result, it endangers many nontarget organisms existing in the natural environment, which comprises both soil and water. The current Review aims to provide a systemic analysis of glyphosate, its various effects on the environment, its subsequent impact on human health and animals, which will lead us toward a better understanding of the issues about herbicide usage and aid in managing it wisely, as in the near the future glyphosate market is aiming for a positive forecast until 2035.
PubMed: 38371781
DOI: 10.1021/acsomega.3c08080 -
Chemosphere Nov 2023The fate of glyphosate and its metabolite AminoMethylPhosponic acid (AMPA) was followed at the catchment of the Sûre river, mainly characterized by small population...
The fate of glyphosate and its metabolite AminoMethylPhosponic acid (AMPA) was followed at the catchment of the Sûre river, mainly characterized by small population density and small and medium-sized wastewater treatment plants (WWTPs). A high concentration of AMPA was found in water samples collected in inlet from different wastewater streams, the industry being the main contributor, while glyphosate resulted mainly in domestic origin. The two molecules were also monitored in the anaerobic digestion as in the supernatant produced after centrifugation (reject water). A total of 0.0713 and 2.24 g/d of glyphosate and AMPA respectively were regularly returned to the activated sludge tank (AST) indicating a 20% impact of the sludge management line on the global wastewater mass balance. Finally, the use of Constructed Wetlands (CWs) in Vertical Flow (VF) configuration was tested as a suitable technology to retain both glyphosate and AMPA (90 and up to 50% elimination respectively) and minimize their discharge into surface water.
Topics: Sewage; Wastewater; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Water; Glyphosate
PubMed: 37619758
DOI: 10.1016/j.chemosphere.2023.139843 -
Current Genetics Dec 2023First marketed as RoundUp, glyphosate is history's most popular herbicide because of its low acute toxicity to metazoans and broad-spectrum effectiveness across plant... (Review)
Review
First marketed as RoundUp, glyphosate is history's most popular herbicide because of its low acute toxicity to metazoans and broad-spectrum effectiveness across plant species. The development of glyphosate-resistant crops has led to increased glyphosate use and consequences from the use of glyphosate-based herbicides (GBH). Glyphosate has entered the food supply, spurred glyphosate-resistant weeds, and exposed non-target organisms to glyphosate. Glyphosate targets EPSPS/AroA/Aro1 (orthologs across plants, bacteria, and fungi), the rate-limiting step in the production of aromatic amino acids from the shikimate pathway. Metazoans lacking this pathway are spared from acute toxicity and acquire their aromatic amino acids from their diet. However, glyphosate resistance is increasing in non-target organisms. Mutations and natural genetic variation discovered in Saccharomyces cerevisiae illustrate similar types of glyphosate resistance mechanisms in fungi, plants, and bacteria, in addition to known resistance mechanisms such as mutations in Aro1 that block glyphosate binding (target-site resistance (TSR)) and mutations in efflux drug transporters non-target-site resistance (NTSR). Recently, genetic variation and mutations in an amino transporter affecting glyphosate resistance have uncovered potential off-target effects of glyphosate in fungi and bacteria. While glyphosate is a glycine analog, it is transported into cells using an aspartic/glutamic acid (D/E) transporter. The size, shape, and charge distribution of glyphosate closely resembles D/E, and, therefore, glyphosate is a D/E amino acid mimic. The mitochondria use D/E in several pathways and mRNA-encoding mitochondrial proteins are differentially expressed during glyphosate exposure. Mutants downstream of Aro1 are not only sensitive to glyphosate but also a broad range of other chemicals that cannot be rescued by exogenous supplementation of aromatic amino acids. Glyphosate also decreases the pH when unbuffered and many studies do not consider the differences in pH that affect toxicity and resistance mechanisms.
Topics: Saccharomyces cerevisiae; Herbicides; Glycine; Plants; Amino Acids, Aromatic
PubMed: 37269314
DOI: 10.1007/s00294-023-01272-4 -
Ecotoxicology and Environmental Safety Apr 2024Glyphosate, ranked as one of the most widely used herbicides in the world, has raised concerns about its potential disruptive effects on sex hormones. However, limited...
Glyphosate, ranked as one of the most widely used herbicides in the world, has raised concerns about its potential disruptive effects on sex hormones. However, limited human evidence was available, especially for children and adolescents. The present study aimed to examine the associations between exposure to glyphosate and sex hormones among participants aged 6-19 years, utilizing data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2016. Children and adolescents who had available data on urinary glyphosate, serum sex steroid hormones, including testosterone (TT), estradiol (E) and sex hormone binding globulin (SHBG), and covariates were selected. Additionally, the ratio of TT to E (TT/E) and the free androgen index (FAI), which was calculated using TT/SHBG, were also included as sex hormone indicators. Survey regression statistical modeling was used to examine the associations between urinary glyphosate concentration and sex hormone indicators by age and sex group. Among the 964 participants, 83.71% had been exposed to glyphosate (>lower limit of detection). The survey regression revealed a marginally negative association between urinary glyphosate and E in the overall population, while this association was more pronounced in adolescents with a significant trend. In further sex-stratified analyses among adolescents, a significant decrease in E, FAI, and TT (p trend <0.05) was observed in female adolescents for the highest quartile of urinary glyphosate compared to the lowest quartile. However, no similar association was observed among male adolescents. Our findings suggest that exposure to glyphosate at the current level may decrease the levels of sex steroids in adolescents, particularly female adolescents. Considering the cross-sectional study design, further research is needed to confirm our findings.
Topics: Child; Humans; Male; Adolescent; Female; Young Adult; Adult; Glyphosate; Nutrition Surveys; Cross-Sectional Studies; Gonadal Steroid Hormones; Testosterone; Estradiol; Sex Hormone-Binding Globulin
PubMed: 38564862
DOI: 10.1016/j.ecoenv.2024.116266