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Evaluation of Food and Food Contaminants
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 5, 2017
William J. Rea, Kalpana D. Patel
Although OP use drastically increased between the 1960s through the late 1990s,327 over the past decade, use has been declining.328 For indoor use, chlorpyrifos has largely been replaced with pyrethroids,329 but research indicates pyrethroids may not necessarily be safer. In an in vitro study comparing the toxicity of a common pyrethroid, cyfluthrin, with chlorpyrifos, at the same doses cyfluthrin induced either an equivalent or higher toxic effect on the growth, survival, and function of primary fetal human astrocytes, and induced inflammatory action of astrocytes that can mediate neurotoxicity.330 In another in vitro study comparing the neurotoxicity of fipronil to chlorpyrifos, fipronil induced more oxidative stress and resulted in lower cell counts for nondifferentiated PC12 cells than chlorpyrifos, and disrupted cell development at lower thresholds, leading the authors to conclude that fipronil was in fact more detrimental to neuronal cell development than chlorpyrifos.331 Although further studies are underway, because of the observed associations in humans and direct effects on neurodevelopmental toxicity in animal studies, caution is warranted for women to avoid direct contact with pesticides during pregnancy.
Use of Physiological and Biochemical Measures in Pollution Biology
Published in Alan G. Heath, Water Pollution and Fish Physiology, 2018
The easiest and quickest temperature tolerance test is the determination of the critical thermal maximum (CTM). This is done by raising the temperature at a constant rate (usually 1°C 3 min) until the test fish lose equilibrium (Bonin, 1981). The endpoint is reasonably sharp, however, differences between pollutant-exposed fish and controls may be small, depending on the pollutant (Paladino et al., 1980; McLeay and Howard, 1977). Heath et al. (1994) found that sublethal exposure of fathead minnow larvae for 24 h to the pyrethroid pesticide cyfluthrin caused a reduction in the upper lethal temperature and an increase in the lower lethal temperature. Thus, the thermal limits of the fish were effectively constricted.
Turfgrass Insects
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
Treating with fast-acting products often only temporarily suppresses ant mounding as this usually fails to control the queen in her underground nest chamber. If contact products such as pyrethroids (bifenthrin, cyfluthrin, deltamethrin, and lambda-cyhalothrin) are used, the best time for application is early in the growing season, just after mounds appear. These applications typically provide 50% to 70% mound suppression for four to six weeks. A combination treatment of a pyrethroid along with a neonic insecticide like imadacloprid, thiamethoxam, or chlothianidin often provides longer term control, up to two to three months. Fipronil is another longer lasting product that has slow knockdown activity, allowing worker ants time to return to the nest and spread the product to other ants. However, it does not have a broad spectrum, does not kill all ant species, and must be used in fire ant regions in compliance with the label. Spot-treating with an insect bait such as hydramethylnon often provides good control if certain precautions are followed. The baits are typically slow acting, allowing worker ants time to feed it to the queen and her brood. Small amounts are sprinkled around mounds but must remain dry as ants are not attracted to wet bait. Once applied to dry turf, irrigation should be withheld for at least 12 hours after application to allow time for the worker ants to carry the bait to the queen. After the queen is eliminated, the colony cannot reproduce and dies out. About two days are needed to eliminate the colony. Baits are usually spot treatment, most often by shaker cans. Early spring is best for applications, since nests are small and thus the buildup of mounds that occurs in late spring and summer is avoided.
Effective preparation of magnetic molecularly imprinted polymer nanoparticle for the rapid and selective extraction of cyfluthrin from honeysuckle
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Yanli Chen, Zenghui Xie, Lanyun Zhang, Xujia Hu
The pyrethroid insecticide is synthesized based on natural pyrethrines extracted from chrysanthemum[7,8]. Among the pyrethroid pesticides, cyfluthrin is a type II pyrethroid. It was registered in the USA in 1987 for the first time and is commonly used for pests such as aphids, cutworms, grain beetles, ants, silverfish, cockroaches, mosquitoes, termites, weevils, fleas, flies, and many others [9, 10], so cyfluthrin is one of the most used pyrethroid insecticides worldwide [11]. But after oral administration, cyfluthrin can be absorbed into blood circulation system, cross the blood-brain barrier, and poison the brain[7]. Therefore, cyfluthrin can affect the central nervous system function of non-target organisms.