Balderrama-Carmona et al., 2019
Balderrama-Carmona, A. P., Valenzuela-Rincon, M., Zamora-Alvarez, L. A., Adan-Bante, N. P., Leyva-Soto, L. A., Silva-Beltran, N. P., & Moran-Palacio, E. F.; “Herbicide biomonitoring in agricultural workers in Valle del Mayo, Sonora Mexico;” Environmental Science and Pollution Research International, 2019; DOI: 10.1007/s11356-019-07087-6.
ABSTRACT:
Valle del Mayo is an important agricultural area at the northwest of Mexico where up to 20,000 L of a mix composed of glyphosate and tordon is used in drains and canals. This study was carried out in order to evaluate the cellular damage caused by glyphosate, aminomethylphosphonic acid (AMPA), and picloram in agricultural workers. Biomonitoring was performed through the quantification of herbicides in urine using HPLC (high-performance liquid chromatography) to then evaluate the cellular damage in exposed people by means of an evaluation of micronuclei and cellular proliferation in lymphocyte cultures. The urine samples (n = 30) have shown a concentration of up to 10.25 mug/L of picloram and 2.23 mug/L of AMPA; no positive samples for glyphosate were reported. The calculation of the external dose reveals that agricultural workers ingest up to 146 mg/kg/day; however, this concentration does not surpass the limits that are allowed internationally. As for the results for the micronuclei test, 53% of the workers showed cellular damage, and the nuclear division index test reported that there was a significant difference (P < 0.05) between the exposed and the control population, which indicated that the exposure time to pesticides in the people of Valle del Mayo can induce alterations which can cause chronic damage. FULL TEXT
Singh et al., 2020
Singh, Simranjeet, Kumar, Vijay, Datta, Shivika, Wani, Abdul Basit, Dhanjal, Daljeet Singh, Romero, Romina, & Singh, Joginder; “Glyphosate uptake, translocation, resistance emergence in crops, analytical monitoring, toxicity and degradation: a review;” Environmental Chemistry Letters, 2020; DOI: 10.1007/s10311-020-00969-z.
ABSTRACT:
The herbicide glyphosate is widely used to control weeds in grain crops. The overuse of glyphosate has induced issues such as contamination of surface water, decreased soils fertility, adverse effects on soil microbiota and possible incorporation in food chains. Here we review biochemical, agricultural, microbiological and analytical aspects of glyphosate. We discuss uptake, translocation, toxicity, degradation, complexation behaviour, analytical monitoring techniques and resistance emergence in crops. We provide data of glyphosate toxicity on different ecosystems. Experiments reveal that excessive glyphosate use induces stress on crops and on non-target plants, and is toxic for mammalians, microorganisms and invertebrates. The long half-life period of glyphosate and its metabolites under different environmental conditions is a major concern. Development of analytical methods for the detection of glyphosate is important because glyphosate has no chromophoric or fluorophoric groups. FULL TEXT
Crump et al., 2020
Crump, K., Crouch, E., Zelterman, D., Crump, C., & Haseman, J.; “Accounting for Multiple Comparisons in Statistical Analysis of the Extensive Bioassay Data on Glyphosate;” Toxicology Science, 2020; DOI: 10.1093/toxsci/kfaa039.
ABSTRACT:
Glyphosate is a widely used herbicide worldwide. In 2015, the International Agency for Research on Cancer (IARC) reviewed glyphosate cancer bioassays and human studies and declared that the evidence for carcinogenicity of glyphosate is sufficient in experimental animals. We analyzed ten glyphosate rodent bioassays, including those in which IARC found evidence of carcinogenicity, using a multi-response permutation procedure that adjusts for the large number of tumors eligible for statistical testing and provides valid false-positive probabilities. The test statistics for these permutation tests are functions of p-values from a standard test for dose-response trend applied to each specific type of tumor. We evaluated three permutation tests, using as test statistics the smallest p-value from a standard statistical test for dose-response trend and the number of such tests for which the p-value is less than or equal to 0.05 or 0.01. The false-positive probabilities obtained from two implementations of these three permutation tests are: smallest p-value: 0.26, 0.17, p-values </= 0.05: 0.08, 0.12, p-values </= 0.01: 0.06, 0.08. In addition, we found more evidence for negative dose-response trends than positive. Thus, we found no strong evidence that glyphosate is an animal carcinogen. The main cause for the discrepancy between IARC’s finding and ours appears to be that IARC did not account for the large number of tumor responses analyzed and the increased likelihood that several of these would show statistical significance simply by chance. This work provides a more comprehensive analysis of the animal carcinogenicity data for this important herbicide than previously available. FULL TEXT
Maderthaner et al., 2020
Maderthaner, M., Weber, M., Takacs, E., Mortl, M., Leisch, F., Rombke, J., Querner, P., Walcher, R., Gruber, E., Szekacs, A., & Zaller, J. G.; “Commercial glyphosate-based herbicides effects on springtails (Collembola) differ from those of their respective active ingredients and vary with soil organic matter content;” Environmental Science and Pollution Research International, 2020; DOI: 10.1007/s11356-020-08213-5.
ABSTRACT:
Glyphosate-based herbicides (GBH) are currently the most widely used agrochemicals for weed control. Environmental risk assessments (ERA) on nontarget organisms mostly consider the active ingredients (AIs) of these herbicides, while much less is known on effects of commercial GBH formulations that are actually applied in the field. Moreover, it is largely unknown to what extent different soil characteristics alter potential side effects of herbicides. We conducted a greenhouse experiment growing a model weed population of Amaranthus retroflexus in arable field soil with either 3.0 or 4.1% soil organic matter (SOM) content and treated these weeds either with GBHs (Roundup LB Plus, Touchdown Quattro, Roundup PowerFlex) or their respective AIs (isopropylammonium, diammonium or potassium salts of glyphosate) at recommended dosages. Control pots were mechanically weeded. Nontarget effects were assessed on the surface activity of the springtail species Sminthurinus niger (pitfall trapping) and litter decomposition in the soil (teabag approach). Both GBHs and AIs increased the surface activity of springtails compared to control pots; springtail activity was higher under GBHs than under corresponding AIs. Stimulation of springtail activity was much higher in soil with higher SOM content than with low SOM content (significant treatment x SOM interaction). Litter decomposition was unaffected by GBHs, AIs or SOM levels. We suggest that ERAs for pesticides should be performed with actually applied herbicides rather than only on AIs and should also consider influences of different soil properties. FULL TEXT
Maggi et al., 2020
Maggi, Federico, la Cecilia, Daniele, Tang, Fiona H. M., & McBratney, Alexander; “The global environmental hazard of glyphosate use;” Science of The Total Environment, 2020, 717; DOI: 10.1016/j.scitotenv.2020.137167.
ABSTRACT:
Agricultural pesticides can become persistent environmental pollutants. Among many, glyphosate (GLP) is under particular scrutiny because of its extensive use and its alleged threats to the ecosystem and human health. Here, we introduce the first global environmental contamination analysis of GLP and its metabolite, AMPA, conducted with a mechanistic dynamic model at 0.5×0.5 degree spatial resolution (about 55 km at the equator) fed with geographically-distributed agricultural quantities, soil and biogeochemical properties, and hydroclimatic variables. Our analyses reveal that about 1% of croplands worldwide (385,000 km2) are susceptible to mid to high contamination hazard and less than 0.1% has a high hazard. Hotspots found in South America, Europe, and East and South Asia were mostly correlated to widespread GLP use in pastures, soybean, and corn; diffuse contributing processes were mainly biodegradation recalcitrance and persistence, while soil residue accumulation and leaching below the root zone contributed locally to the hazard in hotspots. Hydroclimatic and soil variables were major controlling factors of contamination hotspots. The relatively low risk of environmental exposure highlighted in our work for a single active substance does not rule out a greater recognition of environmental pollution by pesticides and calls for worldwide cooperation to develop timely standards and implement regulated strategies to prevent excess global environmental pollution. FULL TEXT
Hendershot et al., 2020
Hendershot, J. Nicholas, Smith, Jeffrey R., Anderson, Christopher B., Letten, Andrew D., Frishkoff, Luke O., Zook, Jim R., Fukami, Tadashi, & Daily, Gretchen C.; “Intensive farming drives long-term shifts in avian community composition;” Nature, 2020, 579(7799), 393-396; DOI: 10.1038/s41586-020-2090-6.
ABSTRACT:
Agricultural practices constitute both the greatest cause of biodiversity loss and the greatest opportunity for conservation. However, little is known about the long-term effects of alternative , given the shrinking scope of protected areas in many regions. Recent studies have documented the high levels of biodiversity— across many taxa and biomes—that agricultural landscapes can support over the short term agricultural practices on ecological communities. Here we document changes in bird communities in intensive-agriculture, diversified-agriculture and natural-forest habitats in 4 regions of Costa Rica over a period of 18 years. Long-term directional shifts in bird communities were evident in intensive- and diversified-agricultural habitats, but were strongest in intensive-agricultural habitats, where the number of endemic and International Union for Conservation of Nature (IUCN) Red List species fell over time. All major guilds, including those involved in pest control, pollination and seed dispersal, were affected. Bird communities in intensive-agricultural habitats proved more susceptible to changes in climate, with hotter and drier periods associated with greater changes in community composition in these settings. These findings demonstrate that diversified agriculture can help to alleviate the long-term loss of biodiversity outside natural protected areas. FULL TEXT
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Silva et al., 2018
Silva, V., Montanarella, L., Jones, A., Fernandez-Ugalde, O., Mol, H. G. J., Ritsema, C. J., & Geissen, V.; “Distribution of glyphosate and aminomethylphosphonic acid (AMPA) in agricultural topsoils of the European Union;” Science of The Total Environment, 2018, 621, 1352-1359; DOI: 10.1016/j.scitotenv.2017.10.093.
ABSTRACT:
Approval for glyphosate-based herbicides in the European Union (EU) is under intense debate due to concern about their effects on the environment and human health. The occurrence of glyphosate residues in European water bodies is rather well documented whereas only few, fragmented and outdated information is available for European soils. We provide the first large-scale assessment of distribution (occurrence and concentrations) of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) in EU agricultural topsoils, and estimate their potential spreading by wind and water erosion. Glyphosate and/or AMPA were present in 45% of the topsoils collected, originating from eleven countries and six crop systems, with a maximum concentration of 2mgkg(-1). Several glyphosate and AMPA hotspots were identified across the EU. Soil loss rates (obtained from recently derived European maps) were used to estimate the potential export of glyphosate and AMPA by wind and water erosion. The estimated exports, result of a conceptually simple model, clearly indicate that particulate transport can contribute to human and environmental exposure to herbicide residues. Residue threshold values in soils are urgently needed to define potential risks for soil health and off site effects related to export by wind and water erosion. FULL TEXT
Smith et al., 2020
Smith, Dylan B., Arce, Andres N., Ramos Rodrigues, Ana, Bischoff, Philipp H., Burris, Daisy, Ahmed, Farah, & Gill, Richard J.; “Insecticide exposure during brood or early-adult development reduces brain growth and impairs adult learning in bumblebees;” Proceedings of the Royal Society B: Biological Sciences, 2020, 287(1922); DOI: 10.1098/rspb.2019.2442.
ABSTRACT:
For social bees, an understudied step in evaluating pesticide risk is how contaminated food entering colonies affects residing offspring development and maturation. For instance, neurotoxic insecticide compounds in food could affect central nervous system development predisposing individuals to become poorer task performers later-in-life. Studying bumblebee colonies provisioned with neonicotinoid spiked nectar substitute, we measured brain volume and learning behaviour of 3 or 12-day old adults that had experienced in-hive exposure during brood and/or early-stage adult development. Micro-computed tomography scanning and segmentation of multiple brain neuropils showed exposure during either of the developmental stages caused reduced mushroom body calycal growth relative to unexposed workers. Associated with this was a lower probability of responding to a sucrose reward and lower learning performance in an olfactory conditioning test. While calycal volume of control workers positively correlated with learning score, this relationship was absent for exposed workers indicating neuropil functional impairment. Comparison of 3- and 12-day adults exposed during brood development showed a similar degree of reduced calycal volume and impaired behaviour highlighting lasting and irrecoverable effects from exposure despite no adult exposure. Our findings help explain how the onset of pesticide exposure to whole colonies can lead to lag-effects on growth and resultant dysfunction. FULL TEXT
Dimitrov et al., 2006
Dimitrov, B. D., Gadeva, P. G., Benova, D. K., & Bineva, M. V.; “Comparative genotoxicity of the herbicides Roundup, Stomp and Reglone in plant and mammalian test systems;” Mutagenesis, 2006, 21(6), 375-382; DOI: 10.1093/mutage/gel044.
ABSTRACT:
The genotoxicities of the herbicides Roundup (glyphosate), Stomp (pendimethaline) and Reglone (diquat), were compared in plant (Crepis capillaris L.) and mouse bone marrow test systems using chromosomal aberrations and micronuclei. Roundup did not induce chromosomal aberrations or micronuclei in either test system. Reglone also did not induce chromosomal aberrations in either test system; however, it increased micronucleus frequency in both plant cells and mouse bone marrow polychromatic erythrocytes (PCEs). The responses of the two test systems to Stomp were quite different. Stomp did not induce chromosomal aberrations in the plant cells, but increased their incidence in mouse cells; Stomp increased the frequency of micronuclei in both test systems. The induction of micronuclei in plant cells may have been due to the spindle-destroying effect of the herbicide, since all concentrations of Stomp produced C-mitoses. The increased chromosomal aberration frequency in mouse bone marrow cells observed at later sampling times after administration of Stomp into animals suggests that the induction of aberrations may be due to biosynthesis of genotoxic metabolites. This conclusion was supported by the coincidence between the frequencies of chromosomal aberrations and of micronucleated PCEs in mouse cells. These data indicate that plant and animal assays are differentially responsive to some pesticides, and these differences may be due to metabolism and their responses to mitotic spindle disruption. FULL TEXT
Sviridov et al., 2015
Sviridov, A. V., Shushkova, T. V., Ermakova, I. T., Ivanova, E. V., Epiktetov, D. O., & Leont’evskii, A. A.; “[Microbial degradation of glyphosate herbicides (review)];” Prikl Biokhim Mikrobiol, 2015, 51(2), 183-190; DOI: 10.7868/s0555109915020221.
ABSTRACT:
This review analyzes the issues associated with biodegradation of glyphosate (N-(phosphonomethyl)glycine), one of the most widespread herbicides. Glyphosate can accumulate in natural environments and can be toxic not only for plants but also for animals and bacteria. Microbial transformation and mineralization of glyphosate, as the only means of its rapid degradation, are discussed in detail. The different pathways of glyphosate catabolism employed by the known destructing bacteria representing different taxonomic groups are described. The potential existence of alternative glyphosate degradation pathways, apart from those mediated by C-P lyase and glyphosate oxidoreductase, is considered. Since the problem of purifying glyphosate-contaminated soils and water bodies is a topical issue, the possibilities of applying glyphosate-degrading bacteria for their bioremediation are discussed. FULL TEXT