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Africa
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Chemical Methods of Vector Control
Published in Jacques Derek Charlwood, The Ecology of Malaria Vectors, 2019
There was a 28%–76% reduction in P. falciparum following the spraying with ICON but a 23% increase in the rest of the state where DDT was used. DDT is known to act as a repellent as much, if not more, than a killing agent. Spraying the outside eaves of houses with lambda-cyhalothrin did not reduce entry rates of A. funestus in Mozambique so the insecticide may not have such a strong repellent effect. One interpretation of the different results from South Africa and Brazil is that a strong repellent is better than an ineffective killing agent (i.e., an insecticide to which the vector has become resistant), but that in the absence of resistance a killing agent (lambdacyhalothrin in this case) is better than a repellent.
Rationale and technique of malaria control
Published in David A Warrell, Herbert M Gilles, Essential Malariology, 2017
David A Warrell, Herbert M Gilles
Deltamethrin, which has a fairly high mammalian toxicity (moderately hazardous; LD50 135 mg/kg), was used at a dosage of 0.05 g/m2 in a field trial in Africa and was safe and effective as a residual spray for at least 2 months. Permethrin, a safer pyrethroid (moderately hazardous; LD50 500 mg/kg), when employed at a dosage of 0.5 g/m2 was fairly effective as a residual spray for about 3 months. The latest synthetic pyrethroid, discovered in the early 1980s and developed as an insecticide for agricultural and public health applications, is lambda-cyhalothrin. The formulations available for residual spraying are 2.5 per cent and 5 per cent emulsifiable concentrate and 10 per cent wettable powder. Application rates are typically in the range of 10–25 mg/m2 or, for prolonged action (6 months), 25–30 mg/m2 are suggested. It is classed as a ‘moderately hazardous’ insecticide, with an LD50 of 56 mg/kg.
Inorganic Chemical Pollutants
Published in William J. Rea, Kalpana D. Patel, Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
William J. Rea, Kalpana D. Patel
Additionally, under 40 CFR § 180.1195, titanium dioxide is exempted from the requirement of a tolerance for residues in or on growing crops, when used as an inert ingredient (UV protectant) in microencapsulated formulation of the insecticide lambda cyhalothrin at no more than 3.0% by weight of the formulation.290 Since this tolerance exemption was established after August 3, 1996, it is not subject to the tolerance reassessment provision of FQPA.
Evaluation of hazards of electronic -cigarette’s liquid refill on testes of mice, complemented by histopathological and chromatographic analysis
Published in Ultrastructural Pathology, 2023
Raghda Elsherif, Nora Z. Abdellah, Ola A. Hussein, Eman S. Shaltout
The present results revealed the presence of Phenol-d5, 5-(2 propenyl)-2(5 H)-Thiophenone, and 4,5-Dimethyl-2-hydroxy benzophenone in the analyzed e-liquid. In agreement with the present results, phenols were reported to be present in nine of the 21 samples tested e-liquid samples. It is well known that phenols can be made by heating polyphenols found in tobacco plants.24,25 In addition to nicotine, phenol, vanillin, and aldehydes, the analyzed e-liquid in the present study was shown to contain a pyrethroid insecticide (Lambda-cyhalothrin). It was previously reported that cigarettes made from flue-cured tobacco contain varying quantities of pyrethroids.26 Beauval and Antherieu27 tested e-liquid samples for 50 different pesticides. Only the organophosphate “chlorpyrifos ethyl” and the herbicide “trifluralin” were detected in some samples.
Clinical presentation of type 1 and type 2 pyrethroid poisoning in humans
Published in Clinical Toxicology, 2022
Manna Sera Jacob, Ramya Iyyadurai, Arun Jose, Jude Joseph Fleming, Grace Rebekah, Anand Zachariah, Samuel George Hansdak, Reginald Alex, Vignesh Kumar Chandiraseharan, Audrin Lenin, John Victor Peter
A differential severity was observed among the compounds that were frequently implicated in pyrethroid poisoning in our setting (Table 3). We observed that lambda-cyhalothrin (type 2 compound) ingestion was associated with moderate to severe toxicity (OR 7.81, 95%CI 1.55–39.4, p = 0.01) (Table 4) when compared with other compounds, with features of paraesthesia, tremors, hypersalivation, depressed sensorium and seizures (Table 3). This is not surprising given that lambda-cyhalothrin, a 4th generation pyrethroid [8], is classified by the World Health Organization (WHO) as moderately hazardous (Class II). Lambda-cyhalothrin has lower oral and dermal LD50 in rats when compared with other pyrethroid compounds [7]. Cypermethrin, another type 2 compound, with a low LD50 in animals, was also associated with paraesthesia, hypersalivation and tremors (Table 3). On the other hand, Transfluthrin, which has a high LD50 in animals and is classified as “unlikely to present acute hazard in normal use” [9], was associated only with mild toxicity in our setting. Patients with transfluthrin poisoning presented mainly with nausea and vomiting and tremors and did not manifest hypersalivation or seizures; only one patient (8.3%) had paraesthesia (Table 3). Transfluthrin is commercially available as mosquito repellents and packaged with the solvent kerosene, which is a mixture of hydrocarbons. The dominant presentation of nausea and vomiting with transfluthrin poisoning could possibly be attributed to the hydrocarbon rather than the pyrethroid per se. Other toxicities of hydrocarbons such as chemical pneumonitis, central nervous system depression and cardiac arrhythmias were not seen in any of our patients [10,11].
Pesticides induced oxidative stress and female infertility: a review
Published in Toxin Reviews, 2020
Jitender Kumar Bhardwaj, Meenu Mittal, Priyanka Saraf, Priya Kumari
Endometrium plays an important role in implantation of the embryo and development of fetus; however, pesticides influence causes endometriosis that causes implantation defects and reduces the pregnancy outcome/conception frequency. This is mostly due to the pesticide-induced oxidative stress generated within endometrium. Dichlorovos administration increased lipid peroxidation in endometrial tissues that increased irregularities in epithelial lining and caused disorganization of the glandular epithelium leading to shrinkage of its epithelial glandular cells (Oral et al.2006). DEHP a phthalate also causes endometriosis (Wang et al.2012a). The effects were found to be ameliorated by antioxidants vitamin E and C, thereby, decreasing MDA level (Oral et al.2006). Similar effects were observed in methyl parathion toxicity and antioxidants treatments on endometrial lining (Guney et al.2007c). Direct exposure of pre-implantation embryo to chlorpyrifos (CPF) can increase apoptotic damage that revealed that the effects of OPs and oxidative stress are responsible for the increased pre-implantation losses in mice (Greenlee et al.2004). The presence of organochlorine pesticides in human placenta (Lopez-Espinosa et al.2007) has been found to be associated with oxidative stress, intrauterine growth restriction, and lower birth weight. Lambda-cyhalothrin (LCT), a pyrethroid, is widely used as an insecticide shows adverse effect in female rat when treated with LCT. Biochemical analysis revealed high MDA level and elevated SOD and CAT activity in treated rat than in the control and so found to be involved in reduction in the number of offspring, increases chances of miscarriage or other obvious signs of pregnancy disorders (Tukhtaev et al.2012). Both in vivo and in vitro studies found the bisphenol-A (BPA) impacts upon uterine morphology and estrogen and progesterone receptors when injected during early gestational days and known to disrupt pregnancy and reduce blastocyst implantation significantly. With increase in dose the uterine luminal area was found expanded, suggesting that BPA exposure during early gestation acts as the disrupter to intrauterine implantation, and shows estrogenic effect (Berger et al.2010).