Agrochemicals: A Brief Overview
Dongyou Liu in Handbook of Foodborne Diseases, 2018
Atrazine is an herbicide of the family of triazines, extensively used for control of broad-leaf weeds and certain grasses (37). Their herbicidal action is due to inhibition of photosynthesis, a process unique to plants (11,37), and all triazines have low acute oral and dermal mammalian toxicity (LD50 = 1–2 g/kg). Animal studies have suggested that atrazine may be carcinogenic, as mammary tumors were reported in female Sprague-Dawley rats (37,38); however, such an effect may involve a primary action on pituitary luteinizing hormone seen only at high doses, and it may thus have a threshold (37). Epidemiological studies of triazine herbicides and cancer have provided inconclusive results (39,40), and atrazine is classified by IARC as a Group 3 carcinogen (not classifiable as to its carcinogenicity to humans).
Golden Fields, Burning Forests and Hungry People
Joyce D’Silva, John Webster in The Meat Crisis, 2017
It has also been problematic in the US, with high levels found in groundwater, and the US Environmental Protection Agency (EPA) has expressed concern about this (EPA, 2007). Some studies in animals have shown atrazine to be an endocrine disruptor (EPA, 2007); however, the EPA has not been convinced of this, although it reviews the research evidence every 15 years. Meanwhile atrazine continues to be used on corn as well as several other crops such as sugarcane and sorghum. Syngenta, which makes atrazine, claims that it saves up to 85 million tonnes of soil erosion every year by supporting conservation tillage and no-till farming (Syngenta, 2016). What is certain is that atrazine does persist in both soil and water for a significant time. In 2012 Syngenta agreed to pay $105 million to water companies in the US Midwest for contamination of their water with atrazine (Findlaw, 2016).
Risk Assessment
David Woolley, Adam Woolley in Practical Toxicology, 2017
Much of the difficulty with environmental hazard prediction lies with the simplicity of the test design and data compared with the complexity of the ecosystem and the difficulties encountered in assessing or predicting exposure. Single species tested in a laboratory environment do not necessarily give a sound basis for hazard characterization and risk assessment. Mesocosm studies may make this process easier but are likely to be undertaken toward the end of the development process due to cost. Certain substance properties make prediction easier, such as estrogenic activity, and these can be relatively easily tested for and related to the likely persistence of the chemical in the environment. Persistence is a significant factor in environmental risk, as shown by the relative persistence of TCDD (Tetrachlorodibenzo-p-dioxin) and atrazine in the soil at 10 and 2 years, respectively. Where a process of degradation is identifiable, associated with a short half-life, this is an indicator of lower risk than for nondegradable chemicals. This presupposes that the degradation products have been identified, remembering that DDE, a metabolite of DDT, is also very persistent. In a manner analogous to that in protein binding in mammals, sequestration of chemicals into compartments, such as clay soils, implies potential for long environmental half-life and possible toxicity if there is a sudden release to produce high concentrations. However, high-affinity sequestration may reduce immediate risk levels slightly.
Atrazine neural and reproductive toxicity
Published in Toxin Reviews, 2022
Hamidreza Sadeghnia, Sara Shahba, Alireza Ebrahimzadeh-Bideskan, Shabnam Mohammadi, Amir Mohammad Malvandi, Abbas Mohammadipour
Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a triazine herbicide and known in chemistry with the molecular formula: C8H14ClN5 (Martins et al. 2018). The solubility of this white powdery herbicide in water is 33 mg/L at 20 °C and is easily soluble in organic solvents (Martins et al. 2018). Atrazine is unstable at high temperatures and has a melting point between 173 °C–175 °C (Lin et al. 2018). It is one of the most widely used herbicides and is used for corn, sugar cane and sorghum. Its low cost, convenient usage, and excellent weed control efficacy have made it widespread (Rastegar-Moghaddam et al. 2019, Tao and Tang 2004). This herbicide is currently used in over 60 countries (Demirci et al. 2018). The annual use of atrazine is 70,000–90,000 tons worldwide (Zhang et al. 2018). For instance, in the United States, it has been used for more than 50 years, predominantly as a herbicide in corn cultivation (Cleary et al. 2019, He et al. 2019). China is the primary producer and user of atrazine. Data indicate that currently, China uses 1000–1500 tons of this herbicide per year, and the area of atrazine-contaminated in Chinese land is more than 1.0 × 1010 hm2 (Yue et al. 2017, Lin et al. 2019).
Protective Effects of Betanin against Oxidative Stress in a Peripheral Artery Vasospasm Model in Rat
Published in Journal of Investigative Surgery, 2021
Kevser Tural, Ozkan Ozden, Zeynep Bilgi, Oğuz Merhan, Celal Sahin Ermutlu, Ayşen Aksoyek
More recently, Eftekhari et al reported protective effects of betanin against atrazine toxicity in vitro, using rat hepatocyte cultures. Atrazine is the most commonly detected drinking water contaminant in USA and mainly exerts its toxic effects on mammals by impairing oxidative phosphorylation, causing endocrine disturbances. Betanin was found to ameliorate hepatotoxicity via decreasing lipid peroxidation, stabilization of mitochondrial membrane and repleting glutathione levels [30]. Betanin was also incorporated into PEGylated gelatin nanoparticles with doxorubicin with the objective of decreasing overall dose of doxorubicin and mitigating toxicity. In a pH responsive nanoparticle, betanin was found to be able to encapsulate and stabilize with doxorubicin and show synergistic effect, measured by increased cell apoptosis in vitro [31].
Effects of atrazine on fish, amphibians, and reptiles: update of the analysis based on quantitative weight of evidence
Published in Critical Reviews in Toxicology, 2019
Mark L. Hanson, Keith R. Solomon, Glen J. Van Der Kraak, Richard A. Brian
There were three new studies that examined behaviors in amphibians following exposure to atrazine (Figure 29). Ehrsam et al. (2016) exposed Cuban tree frog (Osteopilus septentrionalis) tadpoles to 178 μg atrazine/L of atrazine for 7d and characterized responses with and without predator cues (i.e. predatory dragonfly larvae, Libellulidae sp.). The study was poorly conducted with a quality of methods score of 1. They reported the average location and activity in test chamber without cues, and the avoidance (location) and activity in the first 10 min of exposure to a predator cue. No differences in average location of atrazine exposed relative to solvent control animals were reported, while a statistically significant difference between atrazine exposed relative to solvent control animals was reported for activity of animals (∼53% versus ∼39% active, respectively). Atrazine-exposed frogs did not avoid the predator chemical cue for the first 10 min of observation and exhibited no statistically significant lack of avoidance during the entire 20 min exposure. A statistically significant increase in activity of atrazine exposed relative to solvent control animals following exposure to the predator cue was reported. While differences were reported, no linking to actual impairment of survival was attempted. As well, only a single concentration of atrazine (178 μg/L) was used and therefore, as the effects were observed at >100 μg/L, the score for relevance was reduced to 0.
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