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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
In the CHARGE study population, of the pesticides evaluated, OPs were the most commonly applied agricultural pesticide near the home during pregnancy. In the group exposed to OPs within 1.5 km of the home, 21 unique compounds were identified, the most abundant of which was chlorpyrifos (20.7%), followed by acephate (15.4%), and diazinon (14.5%). The second most commonly applied class of pesticides was the pyrethroids, one-quarter of which was esfenvalerate (24%), followed by lambda-cyhalothrin (17.3%), permethrin (16.5%), cypermethrin (12.8%), and tau-fluvalinate (10.5%). Of the carbamates, approximately 80% were methomyl or carbaryl, and of the organochlorines, 60% of all applications were dienochlor. Among those exposed, only one-third were exposed to a single compound over the course of the pregnancy.
Spatial Extrapolation in Ecological Effect Assessment of Chemicals
Published in Keith R. Solomon, Theo C.M. Brock, Dick de Zwart, Scott D. Dyer, Leo Posthuma, Sean M. Richards, Hans Sanderson, Paul K. Sibley, Paul J. van den Brink, Extrapolation Practice for Ecotoxicological Effect Characterization of Chemicals, 2008
Theo C. M. Brock, Lorraine Maltby, Christopher W. Hickey, John Chapman, Keith R. Solomon
The responses observed for the most sensitive measurement endpoints (univariate or multivariate) at each exposure concentration were assigned to the 5 effects classes described in Table 1.3 (Chapter 1). Effect class 1 (effects could not be demonstrated) and effect class 2 (slight effects, usually observed on a single sampling date immediately post application only) were used to derive threshold concentrations for direct toxic effects. For the insecticide chlorpyrifos, 6 model ecosystem experiments were available (1 lotic and 5 lentic studies) from which reliable ecological threshold concentrations for short-term exposure could be derived (Table 7.2). These threshold concentrations ranged from 0.1 to 0.5 µg/L (a fivefold difference). For the herbicide atrazine, no less than 9 suitable model ecosystem experiments (2 lotic and 7 lentic) were available that allowed comparison of threshold concentrations for long-term exposure (Table 7.3). These threshold concentrations differed tenfold and ranged from 2 to 20 µg/L. Brock et al. (2006) summarized the results of several lentic model ecosystem experiments performed with the nonpersistent pyrethroid, lambda-cyhalothrin. All studies were characterized by multiple applications (repeated pulse exposures), and the effect classes 1 to 2 threshold concentrations ranged from 2.7 to 10 ng/L.
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.
Assessment of barrier treatments impacting Aedes albopictus (diptera: culicidae) using lambda-cyhalothrin and pyriproxyfen in a suburban neighborhood in Eastern North Carolina, 2018
Published in International Journal of Environmental Health Research, 2023
Avian V. White, Heidi Knecht, Stephanie L. Richards
Lambda-cyhalothrin, a Type II synthetic pyrethroid adulticide active ingredient (AI), controls a wide range of insect pests in agriculture, homes, gardens, and public health programs (Shukla et al. 2017). In 2004, > 16000 >16,000 kg of lambda-cyhalothrin were used to control pests in California on crops such as alfalfa, vegetables, rice, and other grains, and it is also used to control mosquitoes (Lawler et al. 2007). Lambda-cyhalothrin has been widely used for residual mosquito control since the 1980s, particularly for the control of endophilic Anopheles spp. mosquitoes and Ae. aegypti (Muzari et al. 2014). However, interest in applying this insecticide to vegetation (i.e. barrier treatment) for controlling mosquitoes, such as Ae. albopictus, has increased in recent years (Muzari et al. 2014). A study using lambda-cyhalothrin (Demand®, 25 g AI/L) in a barrier treatment resulted in a significant decrease in mosquito populations, particularly in Verrallina spp. (Muzari et al. 2014). Another study that used Demand® CS (40 g) (AI: lambda-cyhalothrin) as a barrier treatment against Ae. albopictus showed a significant reduction in human landing rate counts in treatment compared to control sites (Li et al. 2010).
Cholinesterase activity as a potential biomarker for neurotoxicity induced by pesticides in vivo exposed Oreochromis niloticus (Nile tilapia): assessment tool for organophosphates and synthetic pyrethroids
Published in Environmental Technology, 2023
Muhammad Amin, Masarrat Yousuf, Mohammad Attaullah, Naveed Ahmad, Mohamad Nor Azra, Mehreen Lateef, Islam Dad Buneri, Ivar Zekker, Gaber El-Saber Batiha, Salma Mostafa Aboelenin, Muhammad Zahoor, Muhammad Ikram, Muhammad Naeem
Pesticides are highly harmful chemicals when discharged into the environment in an untreated manner. Though pesticides are used for the benefit of human beings, they also cause stress to non-targeted organisms. The important sources of environmental pollution by pesticides are from agriculture practices, in the use by the public health and release by industrial discharges [1]. Aquatic pollution caused by pesticides needs immense attention because of their adverse effects on the aquatic organisms including fish mortality. Pesticides reach into the water resources by surface leaching from the agricultural lands and enter the organisms either through food chains or by contact water [2]. Even chronic exposure, to sub-lethal dose of pesticides has shown mortality [3]. Organophosphate (OP) pesticides were first introduced in Germany during 1930s [4]. These pesticides are one of the utmost importantly used groups of pesticides utilized till present in agriculture as they are effective and highly biodegradable and not persistent in the environment [5]. However, there is a lack of accurate dosing developed for them and it was reported that they are also extremely toxic to non-target aquatic organisms. OP pesticides are extremely neurotoxic as they inhibit acetylcholinesterase (AChE) enzymes to block nerve impulses in both – central and peripheral nervous systems [6]. Sub-lethal exposures to this chemical can cause damage to several functions, including respiration, reproduction and behaviour [7–9]. The measurement of the AChE activity is used as a biomarker for organophosphate pesticides in the fish tissue [10–12]. Biomarkers are most significant as they contribute information collection regarding the effects of pollutants on the biological systems [13]. Several reports of the organophosphate pesticides toxicity on fish have been reported [14–16]. Malathion (OP) blocks active sites of the AChE enzyme in the nerve endings leading to trembling, convulsion and finally death of vertebrates [17,18]. A reduction in the total protein content and an alteration in the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes were reported in the brain, gills and muscle tissues of Oreochromis niloticus as a result of malathion, chlorpyripos and lambda-cyhalothrin toxicity [19,20]. Lambda-cyhalothrin is extremely toxic to fish having a great capability to accumulate in the fish muscles [21,22]. Since fish has a weak competency to metabolize such xenobiotics, these pesticides are more toxic to fish as compared to other vertebrates [23–25]. Lambda-cyhalothrin interacts with acetylcholine, a neurotransmitter and causes neurotoxicity due to the inhibition of the AChE enzymes that result in a prolonging excitatory postsynaptic potential terminating [26–29]. Overstimulation of the muscle fibres due to excited neurone, generate severe problems, like paralysis and eventually, death [30]. Thus, the AChE activity could be used as a toxicity biomarker in aquatic ecotoxicology [29,31].