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Current Issues and Challenges of Applying Microalgae in Environmental Biotechnology
Published in Pau Loke Show, Wai Siong Chai, Tau Chuan Ling, Microalgae for Environmental Biotechnology, 2023
Xiao Gui Xing, Gao Ya Qian, Sook Sin Chan, Guo Rui Xin, Kit Wayne Chew, Pau Loke Show
Paraquat is a widely used herbicide and has been banned or strictly restricted by some countries due to its high toxicity. Bai et al. (2019) investigated the sensitivity difference of Microcystis aeruginosa and Chlorella aeruginosa to paraquat by multi endpoint analysis, and the results showed that two kinds of algae had different performances in the photosynthetic process, antioxidant response, oxidative stress, submicroscopic structure change, and growth inhibition. The large-scale destruction of the cell wall and organelle damage of Microcystis aeruginosa by paraquat were observed by transmission electron microscopy (TEM). Wan et al. (2020) discussed the toxicity and biodegradation of trichlorfon (TCF) to freshwater algae Chlamydomonas reinhardtii. Although the growth of Chlamydomonas reinhardtii decreased with the increase of TCF concentration, the analysis of pigment content, chlorophyll fluorescence, and antioxidant enzymes showed that it can produce resistance and adapt to the existence of TCF. Its high tolerance to TCF may have the potential to remove TCF in a natural water environment and treat TCF polluted wastewater. Hence, we can see that the algal toxicity test is also helpful to find microalgae with strong tolerance and potential pollutant treatment potential.
Various Approaches to Transfer Macromolecules into Plants Using Nanoparticles
Published in Devarajan Thangadurai, Saher Islam, Jeyabalan Sangeetha, Natália Cruz-Martins, Biogenic Nanomaterials, 2023
Zahra Hajiahmadi, Reza Sayyad, Reza Shirzadian-Khorramabad, Devarajan Thangadurai
Paraquat is a common herbicide which broadly used in worldwide. Due to desiccating and defoliating properties, it can control the growth of weeds. The high solubility of paraquat in water and fast sorption in soil can have destructive effects on the environment. Grillo et al. (2014) suggested that the encapsulation of paraquat by chitosan nanoparticles prohibit the swift release of herbicide and could diminish problems of toxicity in non-target organisms and soil. The results of toxicity investigations on Allium cepa showed that encapsulated paraquat with chitosan caused less chromosome damage, compared to the free herbicide, while the herbicidal activity of paraquat preserved after encapsulation with chitosan (Grillo et al., 2014). Halloysite nanotube (HNT) is a natural aluminum silicate mineral from the kaolin group with layer by layer that empty space between layers can be an appropriate site for loading of active molecules. However, the controlled delivery systems based on HNT exhibit low ability to long-term sustained release. Zeng et al. (2019) served poly(vinyl alcohol)/starch (PVA/ST) composites as a coating agent for reduction of the release rate of active ingredients of Eupatorium adenophorum Spreng (AIEAS) as a botanical herbicide loaded in HNT. The results indicated slower and more sustained release of AIEAS loaded in HNT-PVA/ST compared to AIEAS with PVA/ST film. In addition, HNT significantly inhibited the erosion of PVA/ST film through reinforcement of the film skeleton which can again reduce the release rate of herbicide into the soil (Zeng et al., 2019).
Alterations in Cellular Enzyme Activity, Antioxidants, Adenylates, and Stress Proteins
Published in Alan G. Heath, Water Pollution and Fish Physiology, 2018
Paraquat is a widely used herbicide. When carp were exposed to doses ranging from 0.5–10 ppm, there was a doubling of the liver phosphorylase activity in fish from the higher concentrations. Glucose-6-phosphatase activity in the liver also was elevated some 40–50%. Using a dose of 0.5 ppm for several days produced a gradual rise in these enzyme activities reaching a fourfold rise at 7 days for the phosphorylase (Simon et al., 1983). No information was given on the LC50 for this chemical, but the fish would appear to have been under considerable stress as these enzyme activations would mobilize carbohydrate. The authors also cite unpublished work that showed that paraquat caused increased lactate dehydrogenase activity. All these changes mean a mobilization of energy from glycogen and an enhanced rate of glycolysis which were probably mediated by increased epinephrine and cortisol.
Loaded paraquaton polymeric nanocapsules and evaluation for cardiotoxicity in Wistar rats
Published in International Journal of Environmental Health Research, 2023
Ali Jafari, Efat Nazari, Mansour Ghaderpoori, Marzieh Rashidipour, Afshin Nazari, Farzaneh Chehelcheraghi, Bahram Kamarehie, Reza Rezaee
Herbicides are widely used as an important constituent for weed control in many agricultural fields (Delirrad et al. 2015a). Thus, their residuals can be found in plants and food products, water bodies, and other media. Approximately, a large amount of these chemicals (about 90%) could finally reach the environment and consequently produce adverse effects on human and other living organisms (Kumar et al. 2018). Among the herbicides, paraquat (1,1′-dimethyl-4,4′-bipyridinium dichloride, PQ) is commonly used to control the weeds because of some chemical and physical properties (A et al. 2006; Delirrad et al. 2015a; Sartori and Vidrio 2018). PQ is a non-selective, fast-acting, contact, and post-emergence herbicide for rapid control of weeds (Moretti et al. 2015; Sartori and Vidrio 2018). The herbicidal mechanism of PQ is due to its interfering with the electron transfer system in chloroplast during photosynthesis process. During this interference, damaging radicals such as superoxide radical, hydroxyl radical, and hydrogen peroxide are inhibiting the conversion of NADP to NADPH and eventually the plant destruction (Hassett et al. 1987; Sartori and Vidrio 2018).
Risk factors associated among respiratory health and banana farming
Published in Archives of Environmental & Occupational Health, 2021
José Martim Marques Simas, Líria Yuri Yamauchi, Maria do Carmo Baracho de Alencar
Among the agrochemicals observed in this study, paraquat was the most prevalent. According to the US Environmental Protection Agency,21 paraquat is classified as highly toxic when inhaled, moderately toxic by the oral route and slightly toxic by dermal absorption. Although no significant statistical association was found between the use of pesticides and the presence of respiratory dysfunction, the related risks are evident. Some health risks associated with chronic exposure to paraquat are wheezing, dyspnea, chronic cough and subclinical gas exchange abnormalities.1 At high doses, paraquat can cause oxidative damage to lung tissue, pulmonary fibrosis, and respiratory failure.22 Glyphosate and carbofuran are considered carcinogenic and can cause problems in the respiratory system due to acute and chronic intoxication.4,5 However, no studies have been found that relate to the presence of glyphosate and carbofuran to changes in spirometry and ventilatory disorders. It should be noted that there are no safe levels for the use of pesticides, and that, in any quantity, contact with this type of product can cause harm to humans and the environment.23,24
Paraquat exposure of backpack sprayers in agricultural area in Thailand
Published in Human and Ecological Risk Assessment: An International Journal, 2020
Pajaree Konthonbut, Pornpimol Kongtip, Noppanun Nankongnab, Mathuros Tipayamongkholgul, Witaya Yoosook, Susan Woskie
One study of paraquat exposure among backpack sprayers in Costa Rican banana plantations found that the sprayers had health problems such as burning eyes from splashes, nosebleeds, blistering and burns on thighs, hands, testicles, legs and back (Van et al. 1996). Paraquat can affect the central nervous system (CNS) damaging dopaminergic neurons with cell bodies in the substantia nigra, causing neurobehavioral syndrome (Brooks et al. 1999). Paraquat exposure has also been associated with Parkinson’s disease (McCormack et al. 2002; Landrigan et al. 2005; Dinis-Oliveira et al. 2006).