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Drift
Published in James N. Seiber, Thomas M. Cahill, Pesticides, Organic Contaminants, and Pathogens in Air, 2022
James N. Seiber, Thomas M. Cahill
Decline of sensitive amphibian populations in the Sierra Nevada has been attributed to drift of PCBs and chlorinated pesticides such as dichlorodiphenyltrichloroethane (DDT) and toxaphene, which may act as endocrine disrupters (National Pesticide Information Center, 2020). Earlier studies sampled frogs from the Sierra Nevada Mountains and found measurable dichlorodiphenyldichloroethylene (DDE) which provided evidence of DDT contamination from prior years (Cory et al., 1970). DDT was banned in 1972 but its residues persist, especially its long-lived breakdown product, DDE. A concentration gradient was noted: frogs in the western slopes of the mountains had higher concentrations of DDT/DDE, indicating they originated from California’s central valley. However, in the case of toxaphene, which was used heavily in the cotton fields of California before 1975, the low levels detected in pacific tree frogs downwind of the source did not provide convincing evidence linking declining populations to toxaphene drift (Angermann et al., 2002).
Role of Persistent Organic Pollutants and Mercury in the Arctic Environment and Indirect Impact on Climate Change
Published in Neloy Khare, Climate Change in the Arctic, 2022
Anoop Kumar Tiwari, Tara Megan Da Lima Leitao
Shrestha et al. (2009) discovered hexachlorobenzene and phenanthrene in contaminated soils (Shrestha et al. 2009). Polychlorinated biphenyls (PCBs) are expressed as 209 congeners (Mullins et al. 1984; Frame 1997). The study also includes dichlorodiphenyltrichloroethane (DDT) to dichlorodiphenyldichloroethylene (DDE) (Zepp et al. 1977), toxaphene and congeners (Casida et al. 1974), mirex (Holdrinet et al. 1978), endrin (Katsoyiannis and Samara 2004), methoxychlor (Monitoring 2014), chlorinated benzenes (Savinov et al. 2011), chlordane compounds (Rigét et al. 2010), polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) (Wittsiepe et al. 2008; Hoferkamp et al. 2010; Savinov et al. 2011). Current-use of pesticides including 2-methyl-4-chlorophenoxyacteic acid, metribuzin and pendimethalin. Phosalone, quizalofop-ethyl, tefluthrin and triallate have also been reported recently (Balmer et al. 2019a, b).
Lakes and Reservoirs: Pollution
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Water Resources and Hydrological Systems, 2020
Subhankar Karmakar, O.M. Musthafa
It includes mainly heavy metals, toxin-producing microphytes, and pesticides from agricultural land. Toxic substances may enter water bodies directly as land runoff from urban streets and mining areas or as agricultural runoff including forestry drainage, discharge of inadequately treated sewage, and industrial effluents, and through deposition of airborne pollutants. Toxic substances can also be created in drinking water when chemicals from treatment plants interact with organic molecules in the raw water to form carcinogenic compounds such as trihalomethanes. A range of heavy metals such as mercury, arsenic, lead, and cadmium; chlorinated substances such as dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), and polychlorinated biphenyls (PCBs); organic substances such as polyaromatic hydrocarbons (PAHs); Dieldrin; etc., create toxic conditions.
Electrochemical reduction of halogenated organic contaminants using carbon-based cathodes: A review
Published in Critical Reviews in Environmental Science and Technology, 2023
Jacob F. King, William A. Mitch
Black carbon has previously been demonstrated to facilitate the transfer of electrons from reducing agents to sorbed halogenated compounds. When dichlorodiphenyldichloroethylene (DDE), a breakdown product of the insecticide DDT, was sorbed to graphite, partial dechlorination was observed via transfer of electrons from H2S through the carbon (K. Ding & Xu, 2016). Other studies demonstrated dechlorination of TCE by sulfides on N-doped carbon materials (L. Ding et al., 2018) and by Fe(II) on bone char (Ai et al., 2020). Similarly, biochar mediated the reduction by microorganisms of pentachlorophenol sorbed to its surface (Yu et al., 2015), and trichloronitromethane sorbed to pyrogenic carbon materials was directly reduced by reduced functional groups in the carbon material (Y. Li et al., 2016; Z. Li et al., 2019). These studies found positive correlations between compound degradation rates and carbon adsorption capacity (Ai et al., 2020; Z. Li et al., 2019), conductivity (Ai et al., 2020; Z. Li et al., 2019; Yu et al., 2015), electron exchange capacity (Ai et al., 2020; Yu et al., 2015), and N-content (L. Ding et al., 2018). Because these carbon properties are frequently correlated, the most important characteristics that facilitate electron transfer are uncertain.
Association of occupational exposure to pesticides with overweight and abdominal obesity in family farmers in southern Brazil
Published in International Journal of Environmental Health Research, 2022
Roberta Andressa Line Araújo, Cleber Cremonese, Ramison Santos, Camila Piccoli, Gabriela Carvalho, Carmen Freire, Raquel Canuto
Wang et al. (2016) conducted a systematic review of observational studies to examine the associations between exposure to environmental pollutants, including pesticides, and obesity in humans. The results showed a positive association between exposure to organochlorine compounds and obesity in the general population and at different stages of life, consistent with the results of studies assessing hexachlorobenzene, dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene pesticides (DDE). From the 1970s onwards, with evidence of the risk to the human population, some organochlorine pesticides were banned from agriculture in the United States and European countries, being gradually replaced with organophosphorus compounds and other chemical groups. A 2019 review study assessed the latest available experimental and epidemiological evidence on the possible influence of organophosphorus pesticides on obesity and development of type 2 diabetes. The authors concluded that, despite the small number of epidemiological studies addressing the topic, organophosphorus compounds seem to be a predisposing factor for obesity in adult farmers, although the mechanisms involved are not fully understood yet (Czajka et al. 2019).
Dichlorodiphenyltrichloroethane (DDT) degradation by Streptomyces sp. isolated from DDT contaminated soil
Published in Bioremediation Journal, 2021
Koji Ito, Ahmad Mahmood, Ryota Kataoka, Kazuhiro Takagi
Persistent organic pollutants as categorized under the Stockholm Convention 2001 (Stockholm Convention 2001) have long been used in controlling pests of animals and crop plants. In the initial years of development, such chemicals were used extensively and sometimes directly on animal bodies. Dichlorodiphenyltrichloroethane (DDT) is a persistent organic pollutant too that has been banned in most parts of the world but is still being produced and used in some parts (van den Berg, Manuweera, and Konradsen 2017). Lipophilicity of DDT makes it prone to accumulation in fatty tissues of living organisms which constitute top of the ecological pyramid through its entry into food chain (Jensen et al. 1969). Such a buildup leads to certain disorders including those of central neural system, liver and kidneys alongside disruptions in reproduction (ATSDR 2019). For human bodies, the chronical effects from long-term exposure is concerned, rather than short-term acute effects. Especially, incidence of DDT in human milk has raised serious concerns about infant health (Torres-Arreola et al. 1999). Dichlorodiphenyldichloroethylene (DDE), which is the major DDT metabolite, has been more persistent in the environment than DDT itself and leads to inhibition of androgen binding to the androgen receptor, which consequently leads to disruptions in male sex development in wildlife (Thomas, Ou, and Al-Agely 2008; Kelce et al. 1995).