Insecticides
Frank A. Barile in Barile’s Clinical Toxicology, 2019
OC insecticides are low–molecular weight, fat-soluble compounds with greater selectivity for lipid storage in insects. As a group, these polychlorinated cyclic compounds are structurally similar, especially the stereo isomers dieldrin and endrin. Table 28.3 summarizes the chemical properties and human and animal toxicological profiles of some popular OC insecticides. Figure 28.3 illustrates the structural features of three representative OC compounds. The stereo configuration of endrin is noticeably different from the planar structures of lindane and DDT. The polychlorinated attachments on each of the compounds, however, are similar and are responsible for the insecticidal activity.Structures of selected organochlorine insecticides. DDT = dichlorodiphenyl-trichloroethane; lindane = γ-benzene hexachloride.
Community and environment as determinants of health
Ben Y.F. Fong, Martin C.S. Wong in The Routledge Handbook of Public Health and the Community, 2021
Altogether, the POPs, such as polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs), polycyclic aromatic hydrocarbons (PAHs), and organochlorine pesticides like dichlorodiphenyltrichloroethane (DDT), can have a direct chemical toxic effect when humans consume the polluted water. PCBs and PBBs are endocrine-disrupting compounds. They can potentially affect people’s reproductive system and the newborn’s outcome, although there are still insufficient research findings to prove any causative pathology. The POPs can also enter and accumulate in the food chain, which ultimately affects human beings when various types of seafood are consumed, especially when people ingested bivalves and small fish as a whole, microplastics and POPs can be easily absorbed because they are concentrated in the guts of marine organisms.
Pest Control in Modern Public Health
Jerome Goddard in Public Health Entomology, 2022
From ancient times, humans have occasionally used chemical compounds to try to ward off pests, for example, sulfur for itch mites2 (we now know that sulfur is an effective acaricide that is relatively safe for human use).3 However, during the late 1800s copper sulfate, nicotine, fluorides, pyre-thrum powder, and arsenicals came into widespread use as insecticides (Figure 2.2). For example, sodium silicoflouride was used to control ecto-parasites on livestock as well as crawling insects in houses and buildings (Figure 2.2D). These inorganic compounds, while not miracle drugs, were certainly better than nothing, but large dosages were required. In the 1930s, scientists found that the synthetic compound paradichlorobenzene, which had been used extensively for clothes moth control, was effective against peachtree borers. Then scientists discovered that substituted phenolic compounds had insecticidal properties, and thus began the systematic search for related synthetic compounds. DDT, one of the most famous of all pesticides, was first synthesized in 1874, but its insecticidal properties were not discovered until 19394 (Figure 2.3). DDT was used with great success in the second half of World War II to control malaria and typhus among civilians and troops, being sprayed directly on people and property (Figure 2.4). Other chlorinated hydrocarbons were soon developed, such as lindane, endrin, aldrin, chlordane, and many others. These compounds had very long residual effects, still killing insects 10–30 years after application.
Intensity of pyrethroid resistance in Anopheles culicifacies s.l. (Diptera: Culicidae) in Odisha State, India
Published in Pathogens and Global Health, 2020
Sudhansu Sekhar Sahu, Sonia Thankachy, Smrutidhara Dash, Gunasekaran Kasinathan, Ashwani Kumar
India is a highly malarious country contributing 10, 90,724 cases (89%) in Southeast Asia [1]. Among the six principal malaria vectors transmitting the disease in India, Anopheles culicifacies s.l. (Diptera: Culicidae) is the major widespread species contributing around 65% of malaria incidences in India [2]. Vector control program in the country mainly depends on indoor residual spraying (IRS) or long-lasting insecticidal nets (LLINs) [3,4]. Under the national anti-malaria program, dichlorodiphenyl-trichloroethane (DDT) was introduced in the early 1950s for vector control and later hexachlorocyclohexane (HCH) followed by malathion and recently synthetic pyrethroids (SPs) in 1990s were used to manage the insecticide resistance in An. culicifacies s.l [5]. Currently, LLIN is the prime tool for vector control in India [5]. The success of the intervention is based on the susceptibility of malaria vectors to pyrethroids. Currently, pyrethroids are the only class of insecticides used for LLINs production [6].
Pyrethroid based pesticides – chemical and biological aspects
Published in Critical Reviews in Toxicology, 2021
Anandha Rao Ravula, Suresh Yenugu
The major breakthrough in the development of pesticides started during World War II with the production of environmentally persistent first-generation synthetic pesticides namely, the organochlorines; and prominent among them were aldrin and dichlorodiphenyltrichloroethane (DDT). The second-generation organophosphate pesticides such as malathion were discovered between 1950 and 1955 followed by triazine weedicides during 1955–1960 and their usage reached its peak by 1961. Owing to the public attention toward excessive usage of pesticides and the health hazards elegantly described in the famous book “Silent Spring”, the use of pesticides decreased drastically by 1962 (Carson 1962). Following this, a new method of integrated pest management (IPM) came into existence in which biological predators or parasites were used to control pests. Albeit the population of pests reduced significantly, IPM methods did not display substantial effect akin to chemical pesticides. During 1970–1980s, pyrethroids, sulfonylureas, synthetic fungicides and other chemical pesticides were introduced. DDT was completely banned in USA followed by restrictions on usage of endosulfan, dieldrin and lindane in early 1970s. An international treaty derived at Stockholm Convention held in 2001 to which 179 nations were signatories, resolved to completely ban the use of twelve persistent organic pollutants including DDT (SCPOP 2001). On the same lines, European Union (EU) supported to ban on the use of nicotinoids in 2013.
In vitro effect of DDE exposure on the regulation of B-TC-6 pancreatic beta cell insulin secretion: a potential role in beta cell dysfunction and type 2 diabetes mellitus
Published in Toxicology Mechanisms and Methods, 2021
Antonio B. Ward, Mary B. Dail, Janice E. Chambers
Human exposure to DDT occurs primarily through consumption of contaminated food especially meat, fish and dairy products (Lee et al. 2014). Metabolism is similar in humans and rodents with the stable metabolite, p,p’-DDE, being found at higher concentrations than DDT throughout the body in proportion to the tissue’s lipid content. Since excretion is slow, both DDT and DDE may persist in the human body for decades after exposure (ATSDR, 2019). Although both are found in human serum, DDE levels have shown a better correlation to obesity, dyslipidemia, and insulin resistance (Lee et al. 2011) so we chose to focus on the effect of DDE exposure. The purpose of this study was to investigate in vitro DDE’s ability to alter mechanisms that regulate pancreatic insulin secretion in response to changes in glucose levels.
Related Knowledge Centers
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