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77-592: A bayou is often an anabranch or minor braid of a braided channel that is slower than the mainstem , often becoming boggy and stagnant. Though fauna varies by region, many bayous are home to crawfish , certain species of shrimp , other shellfish , catfish , frogs, toads , salamanders , newts , American alligators , American crocodiles , herons , lizards, turtles, tortoises , spoonbills , snakes, and leeches , as well as many other species. The word entered American English via Louisiana French in Louisiana and

154-405: A river with many anabranches, whilst an anastomosing river is an organic-rich subset of this river type. The term braided river describes watercourses which are divided by small islands into multiple channel threads within a single main channel, but the term does not describe the multiple channels of an anabranching river. A distributary is a branch of a river that does not rejoin

231-603: A direct result of the Deepwater horizon oil spill. This was determined by examining rates of wetland loss in the region from the year prior to the oil spill and contrasting that with the rates of wetland loss after the oil spill. The study noted significant land loss in regions not impacted by wave activity, further demonstrating that the land degradation was caused by oil rather than other sources of weathering from waves and cyclones. Other notable oil spills affecting bayous include 4,000 U.S. gallons (about 15,141.65 L) of oil spilling in

308-509: A lake near Bayou Sorrel in Louisiana and 20,000 U.S. gallons (about 75,708.24 L) of oil spilling into Saint Bernard Parish waters and the adjacent Bayou Bienvenue in Louisiana. Both incidents occurred in 2022. Oil spills harm bayous as oil is toxic to most animals. In vapor form, oil leads to lung, liver, and nervous system dysfunction if inhaled. Ingested oil poses threats to the digestive tract. Oil matts feathers and fur, resulting in disruptions in

385-733: A patent in 1934 by Wolfgang von Leuthold. DDT's insecticidal properties were not, however, discovered until 1939 by the Swiss scientist Paul Hermann Müller , who was awarded the 1948 Nobel Prize in Physiology and Medicine for his efforts. DDT is the best-known of several chlorine -containing pesticides used in the 1940s and 1950s. During this time, the use of DDT was driven by protecting American soldiers from diseases in tropical areas. Both British and American scientists hoped to use it to control spread of malaria , typhus , dysentery , and typhoid fever among overseas soldiers, especially considering that

462-1063: A possible association with liver cancer and biliary tract cancer are conflicting: workers who did not have direct occupational DDT contact showed increased risk. White men had an increased risk, but not white women or black men. Results about an association with multiple myeloma, prostate and testicular cancer, endometrial cancer and colorectal cancer have been inconclusive or generally do not support an association. A 2017 review of liver cancer studies concluded that "organochlorine pesticides, including DDT, may increase hepatocellular carcinoma risk". A 2009 review, whose co-authors included persons engaged in DDT-related litigation, reached broadly similar conclusions, with an equivocal association with testicular cancer. Case–control studies did not support an association with leukemia or lymphoma. The question of whether DDT or DDE are risk factors in breast cancer has not been conclusively answered. Several meta analyses of observational studies have concluded that there

539-471: A predictor of breast cancer, and a marker of high risk". Malaria remains the primary public health challenge in many countries. In 2015, there were 214 million cases of malaria worldwide resulting in an estimated 438,000 deaths, 90% of which occurred in Africa. DDT is one of many tools to fight the disease. Its use in this context has been called everything from a "miracle weapon [that is] like Kryptonite to

616-443: A resurgence. In many areas early successes partially or completely reversed, and in some cases rates of transmission increased. The program succeeded in eliminating malaria only in areas with "high socio-economic status, well-organized healthcare systems, and relatively less intensive or seasonal malaria transmission". DDT was less effective in tropical regions due to the continuous life cycle of mosquitoes and poor infrastructure. It

693-570: A role in the elimination of malaria in Europe and North America . Despite concerns emerging in the scientific community, and lack of research, the FDA considered it safe up to 7 parts per million in food. There was a large economic incentive to push DDT into the market and sell it to farmers, governments, and individuals to control diseases and increase food production. DDT was also a way for American influence to reach abroad through DDT-spraying campaigns. In

770-439: A wetland system impacts its carbon exchange with the environment. Inhibiting a wetland's ability to sequester carbon further damages the status of the wetland as a carbon sink . This poses larger-scale issues as it alters the exchange of carbon dioxide with the atmosphere and environment. The use of pesticides in agriculture poses further threats to bayou ecosystems. A study conducted on three bayous (Cow Oak, Howden, Roundaway) in

847-517: Is a probable carcinogen , and it has been linked to adverse health effects in both humans and wildlife. Several oil spills have impacted bayou regions, including the Deepwater Horizon oil spill of 2010. This oil spill occurred off the Louisiana coast and resulted in the deaths of 11 people and the release of over 4.9 million barrels of oil into the ocean. The bayou wetlands of Bataria Bay, Louisiana experienced increased shoreline erosion as

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924-645: Is a major factor in the comeback of the bald eagle (the national bird of the United States ) and the peregrine falcon from near-extinction in the contiguous United States . The evolution of DDT resistance and the harm both to humans and the environment led many governments to curtail DDT use. A worldwide ban on agricultural use was formalized under the Stockholm Convention on Persistent Organic Pollutants , which has been in effect since 2004. Recognizing that total elimination in many malaria-prone countries

1001-639: Is also conferred by up-regulation of genes expressing cytochrome P450 in some insect species, as greater quantities of some enzymes of this group accelerate the toxin's metabolism into inactive metabolites. Genomic studies in the model genetic organism Drosophila melanogaster revealed that high level DDT resistance is polygenic, involving multiple resistance mechanisms. In the absence of genetic adaptation, Roberts and Andre 1994 find behavioral avoidance nonetheless provides insects with some protection against DDT. The M918T mutation event produces dramatic kdr for pyrethroids but Usherwood et al. 2005 find it

1078-461: Is also known to have been in use, as in "Pine Buyou", used in a description by Congress in 1833 of Arkansas Territory . As of 2016 "bye-you" US : / ˈ b aɪ . uː / is the most common pronunciation, while a few use "bye-oh" US : / ˈ b aɪ . oʊ / , although that pronunciation is declining. The term Bayou Country is most closely associated with Cajun and Creole cultural groups derived from French settlers and stretching along

1155-426: Is applied to the inside walls of homes to kill or repel mosquitoes. This intervention, called indoor residual spraying (IRS), greatly reduces environmental damage. It also reduces the incidence of DDT resistance. For comparison, treating 40 hectares (99 acres) of cotton during a typical U.S. growing season requires the same amount of chemical to treat roughly 1,700 homes. DDT is a persistent organic pollutant that

1232-477: Is clofenotane. Commercial DDT is a mixture of several closely related compounds. Due to the nature of the chemical reaction used to synthesize DDT, several combinations of ortho and para arene substitution patterns are formed. The major component (77%) is the desired p , p ' isomer . The o , p ' isomeric impurity is also present in significant amounts (15%). Dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) make up

1309-415: Is considered likely to be a human carcinogen although the majority of studies suggest it is not directly genotoxic . DDE acts as a weak androgen receptor antagonist , but not as an estrogen . p , p ' -DDT, DDT's main component, has little or no androgenic or estrogenic activity. The minor component o , p ' -DDT has weak estrogenic activity. DDT is classified as "moderately toxic" by

1386-500: Is currently unfeasible in the absence of affordable/effective alternatives for disease control, the convention exempts public health use within World Health Organization (WHO) guidelines from the ban. DDT still has limited use in disease vector control because of its effectiveness in killing mosquitos and thus reducing malarial infections, but that use is controversial due to environmental and health concerns. DDT

1463-536: Is entirely ineffective against DDT. Scott 2019 believes this test in Drosophila oocytes holds for oocytes in general. DDT was first synthesized in 1874 by Othmar Zeidler under the supervision of Adolf von Baeyer . It was further described in 1929 in a dissertation by W. Bausch and in two subsequent publications in 1930. The insecticide properties of "multiple chlorinated aliphatic or fat-aromatic alcohols with at least one trichloromethane group" were described in

1540-556: Is highly hydrophobic and nearly insoluble in water but has good solubility in most organic solvents , fats and oils . DDT does not occur naturally and is synthesised by consecutive Friedel–Crafts reactions between chloral ( CCl 3 CHO ) and two equivalents of chlorobenzene ( C 6 H 5 Cl ), in the presence of an acidic catalyst . DDT has been marketed under trade names including Anofex, Cezarex, Chlorophenothane, Dicophane, Dinocide, Gesarol, Guesapon, Guesarol, Gyron, Ixodex, Neocid, Neocidol and Zerdane; INN

1617-558: Is no overall relationship between DDT exposure and breast cancer risk. The United States Institute of Medicine reviewed data on the association of breast cancer with DDT exposure in 2012 and concluded that a causative relationship could neither be proven nor disproven. A 2007 case-control study using archived blood samples found that breast cancer risk was increased 5-fold among women who were born prior to 1931 and who had high serum DDT levels in 1963. Reasoning that DDT use became widespread in 1945 and peaked around 1950, they concluded that

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1694-410: Is one of many tools to fight malaria, which remains the primary public health challenge in many countries. WHO guidelines require that absence of DDT resistance must be confirmed before using it. Resistance is largely due to agricultural use, in much greater quantities than required for disease prevention. DDT is similar in structure to the insecticide methoxychlor and the acaricide dicofol . It

1771-540: Is readily adsorbed to soils and sediments , which can act both as sinks and as long-term sources of exposure affecting organisms. Depending on environmental conditions, its soil half-life can range from 22 days to 30 years. Routes of loss and degradation include runoff, volatilization, photolysis and aerobic and anaerobic biodegradation . Due to hydrophobic properties, in aquatic ecosystems DDT and its metabolites are absorbed by aquatic organisms and adsorbed on suspended particles, leaving little DDT dissolved in

1848-638: Is thought to originate from the Choctaw word bayuk , which means "small stream". After first appearing in the 17th century, the term is found in 18th century accounts and maps, often as bayouc or bayouque , where it was eventually shortened to its current form. The first settlements of the Bayou Têche and other bayous were founded by the Louisiana Creoles , and the bayous are commonly associated with Creole and Cajun culture. An alternative spelling, "buyou",

1925-464: Is toxic to a wide range of living organisms, including marine animals such as crayfish , daphnids , sea shrimp and many species of fish . DDT, DDE and DDD magnify through the food chain , with apex predators such as raptor birds concentrating more chemicals than other animals in the same environment. They are stored mainly in body fat . DDT and DDE are resistant to metabolism; in humans, their half-lives are 6 and up to 10 years, respectively. In

2002-751: The Gulf Coast from Houston, Texas, to Mobile, Alabama, and picking back up in South Florida around the Everglades , with its center in New Orleans, Louisiana. The term may also be associated with the homelands of certain Choctaw tribal groups. Houston has the nickname "Bayou City". Anthropogenic influences have damaged bayou ecosystems over the years. Bayous are susceptible to pollution such as runoff from nearby urban communities (which can result in eutrophication ) and oil spills given their low-lying position in

2079-489: The South Pacific , it was sprayed aerially for malaria and dengue fever control with spectacular effects. While DDT's chemical and insecticidal properties were important factors in these victories, advances in application equipment coupled with competent organization and sufficient manpower were also crucial to the success of these programs. In 1945, DDT was made available to farmers as an agricultural insecticide and played

2156-563: The watercourse and rejoins the main stem downstream. Local anabranches can be the result of small islands in the watercourse . In larger anabranches, the flow can diverge for a distance of several or even hundreds of kilometers before rejoining the main channel. The term anabranch , in its hydrological meaning, is used more frequently in Australia than in the rest of the English-speaking world. The term anabranching river describes

2233-507: The 1944 issue of Life magazine there was a feature regarding the Italian program showing pictures of American public health officials in uniforms spraying DDT on Italian families. In 1955, the World Health Organization commenced a program to eradicate malaria in countries with low to moderate transmission rates worldwide, relying largely on DDT for mosquito control and rapid diagnosis and treatment to reduce transmission. The program eliminated

2310-715: The 1950s the federal government began tightening regulations governing its use. These events received little attention. Women like Dorothy Colson and Mamie Ella Plyler of Claxton, Georgia , gathered evidence about DDT's effects and wrote to the Georgia Department of Public Health, the National Health Council in New York City, and other organizations. In 1957 The New York Times reported an unsuccessful struggle to restrict DDT use in Nassau County, New York , and

2387-618: The EPA's internal staff stating that DDT was not an imminent danger. However, these findings were criticized, as they were performed mostly by economic entomologists inherited from the United States Department of Agriculture , who many environmentalists felt were biased towards agribusiness and understated concerns about human health and wildlife. The decision thus created controversy. The EPA held seven months of hearings in 1971–1972, with scientists giving evidence for and against DDT. In

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2464-582: The Palos Verdes Shelf area of the Montrose Chemical Superfund site exhibited continued thin-shell problems, though DDT's role in the decline of the California condor is disputed. The biological thinning mechanism is not entirely understood, but DDE appears to be more potent than DDT, and strong evidence indicates that p , p ' -DDE inhibits calcium ATPase in the membrane of

2541-587: The U.S. National Toxicology Program (NTP) and "moderately hazardous" by WHO, based on the rat oral LD 50 of 113 mg/kg. Indirect exposure is considered relatively non-toxic for humans. Primarily through the tendency for DDT to build up in areas of the body with high lipid content, chronic exposure can affect reproductive capabilities and the embryo or fetus. In 2015, the International Agency for Research on Cancer classified DDT as Group 2A "probably carcinogenic to humans". Previous assessments by

2618-456: The U.S. National Toxicology Program classified it as "reasonably anticipated to be a carcinogen" and by the EPA classified DDT, DDE and DDD as class B2 "probable" carcinogens ; these evaluations were based mainly on animal studies. A 2005 Lancet review stated that occupational DDT exposure was associated with increased pancreatic cancer risk in 2 case control studies, but another study showed no DDE dose-effect association. Results regarding

2695-716: The US before the 1972 ban. Usage peaked in 1959 at about 36,000 tonnes. China ceased production in 2007, leaving India the only country still manufacturing DDT; it is the largest consumer. In 2009, 3,314 tonnes were produced for malaria control and visceral leishmaniasis . In recent years, in addition to India, just seven other countries, all in Africa, are still using DDT. In insects, DDT opens voltage-sensitive sodium ion channels in neurons , causing them to fire spontaneously, which leads to spasms and eventual death. Insects with certain mutations in their sodium channel gene are resistant to DDT and similar insecticides. DDT resistance

2772-785: The United States, these chemicals were detected in almost all human blood samples tested by the Centers for Disease Control in 2005, though their levels have sharply declined since most uses were banned. Estimated dietary intake has declined, although FDA food tests commonly detect it. Despite being banned for many years, in 2018 research showed that DDT residues are still present in European soils and Spanish rivers. The chemical and its breakdown products DDE and DDD caused eggshell thinning and population declines in multiple North American and European bird of prey species. Both laboratory experiments and field studies confirmed this effect. The effect

2849-717: The accuracy of giving animals high amounts of pesticides for cancer potential. Industry sought to overturn the ban, while the EDF wanted a comprehensive ban. The cases were consolidated, and in 1973 the United States Court of Appeals for the District of Columbia Circuit ruled that the EPA had acted properly in banning DDT. During the late 1970s, the EPA also began banning organochlorines, pesticides that were chemically similar to DDT. These included aldrin, dieldrin, chlordane, heptachlor, toxaphene, and mirex. Some uses of DDT continued under

2926-439: The ages of 14–20 were a critical period in which DDT exposure leads to increased risk. This study, which suggests a connection between DDT exposure and breast cancer that would not be picked up by most studies, has received variable commentary in third-party reviews. One review suggested that "previous studies that measured exposure in older women may have missed the critical period". The National Toxicology Program notes that while

3003-422: The animal's ability to insulate themselves in colder temperatures. Matted bird feathers lose properties that aid in flying and swimming. Such disruptions in individual adaptive ability may lead to trophic cascades in a bayou community.   Human development activities, such as the increase of impervious surfaces , results in quicker, high intensity flood pulses, delivering larger quantities of these nutrients to

3080-467: The balance of impurities in commercial samples. DDE and DDD are also the major metabolites and environmental breakdown products. DDT, DDE and DDD are sometimes referred to collectively as DDX. DDT has been formulated in multiple forms, including solutions in xylene or petroleum distillates , emulsifiable concentrates , water- wettable powders , granules, aerosols , smoke candles and charges for vaporizers and lotions. From 1950 to 1980, DDT

3157-508: The beginning. Opposition to DDT was focused by the 1962 publication of Rachel Carson 's book Silent Spring . It talked about environmental impacts that correlated with the widespread use of DDT in agriculture in the United States, and it questioned the logic of broadcasting potentially dangerous chemicals into the environment with little prior investigation of their environmental and health effects. The book cited claims that DDT and other pesticides caused cancer and that their agricultural use

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3234-528: The dangers of using the pesticide DDT in agriculture. DDT had been researched and manufactured in St. Louis by the Michigan Chemical Corporation , later purchased by Velsicol Chemical Corporation , and had become an important part of the local economy. Citing research performed by Michigan State University in 1946, Robinson, a past president of the local Conservation Club, opined that: perhaps

3311-617: The disease in "North America, Europe, the former Soviet Union ", and in " Taiwan , much of the Caribbean , the Balkans , parts of northern Africa, the northern region of Australia, and a large swath of the South Pacific" and dramatically reduced mortality in Sri Lanka and India. However, failure to sustain the program, increasing mosquito tolerance to DDT, and increasing parasite tolerance led to

3388-615: The ecosystem at a much more rapid rate. Impervious surfaces include roads, housing developments, and parking lots that replace natural vegetation, typically associated with human development and urbanization. When impervious surfaces are installed, the layer of soil that stores water is damaged/removed, resulting in a lack of permeable surfaces to absorb rainfall and floodwater. Bayous have experienced trends of land cover loss and conversion to impervious surfaces, of which has been associated with influxes of metals such as aluminum, copper, iron, lead, and zinc. Heavy metals in sediments and ultimately

3465-535: The eggs of peregrine falcons and California condors and finding that increased levels corresponded with thinner shells. In response to an EDF suit, the U.S. District Court of Appeals in 1971 ordered the EPA to begin the de-registration procedure for DDT. After an initial six-month review process, William Ruckelshaus , the Agency's first Administrator rejected an immediate suspension of DDT's registration, citing studies from

3542-425: The environment and were endangering human health. Silent Spring was a best seller, and public reaction to it launched the modern environmental movement in the United States. The year after it appeared, President John F. Kennedy ordered his Science Advisory Committee to investigate Carson's claims. The committee's report "add[ed] up to a fairly thorough-going vindication of Rachel Carson's Silent Spring thesis", in

3619-507: The former western German states. By 1991, total bans, including for disease control, were in place in at least 26 countries; for example, Cuba in 1970, the US in the 1980s, Singapore in 1984, Chile in 1985, and the Republic of Korea in 1986. The Stockholm Convention on Persistent Organic Pollutants , which took effect in 2004, put a global ban on several persistent organic pollutants , and restricted DDT use to vector control . The convention

3696-404: The greatest danger from D.D.T. is that its extensive use in farm areas is most likely to upset the natural balances, not only killing beneficial insects in great number but by bringing about the death of fish, birds, and other forms of wild life either by their feeding on insects killed by D.D.T. or directly by ingesting the poison. As its production and use increased, public response was mixed. At

3773-480: The high efficiency of DDT as a contact poison against several arthropods ". The WHO 's anti-malaria campaign of the 1950s and 1960s relied heavily on DDT and the results were promising, though there was a resurgence in developing countries afterwards. By October 1945, DDT was available for public sale in the United States. Although it was promoted by government and industry for use as an agricultural and household pesticide, there were also concerns about its use from

3850-536: The issue came to the attention of the popular naturalist-author Rachel Carson when a friend, Olga Huckins , wrote to her including an article she had written in the Boston Globe about the devastation of her local bird population after DDT spraying. William Shawn , editor of The New Yorker , urged her to write a piece on the subject, which developed into her 1962 book Silent Spring . The book argued that pesticides , including DDT, were poisoning both wildlife and

3927-442: The lower Mississippi River Basin found that the addition of nitrogen and phosphorus to sample mesocosms affected the decomposition of maize crop and willow oak detritus. While both species showed an increase in decomposition rate after N and P nutrient enhancement, the maize crop broke down faster than the native willow oak. The maize crop also had a significantly faster microbial respiration rate. The changes in microbial respiration of

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4004-545: The main channel; these are common on and near river deltas . A bayou is often an anabranch. An anabranch that gets cut off from the main channel becomes an oxbow lake , known in Australia as a billabong . DDT Dichlorodiphenyltrichloroethane , commonly known as DDT , is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride . Originally developed as an insecticide , it became infamous for its environmental impacts . DDT

4081-493: The majority of studies have not found a relationship between DDT exposure and breast cancer that positive associations have been seen in a "few studies among women with higher levels of exposure and among certain subgroups of women". A 2015 case control study identified a link (odds ratio 3.4) between in-utero exposure (as estimated from archived maternal blood samples) and breast cancer diagnosis in daughters. The findings "support classification of DDT as an endocrine disruptor,

4158-933: The mosquitoes", to "toxic colonialism". Before DDT, eliminating mosquito breeding grounds by drainage or poisoning with Paris green or pyrethrum was sometimes successful. In parts of the world with rising living standards, the elimination of malaria was often a collateral benefit of the introduction of window screens and improved sanitation. A variety of usually simultaneous interventions represents best practice. These include antimalarial drugs to prevent or treat infection; improvements in public health infrastructure to diagnose, sequester and treat infected individuals; bednets and other methods intended to keep mosquitoes from biting humans; and vector control strategies such as larviciding with insecticides, ecological controls such as draining mosquito breeding grounds or introducing fish to eat larvae and indoor residual spraying (IRS) with insecticides, possibly including DDT. IRS involves

4235-597: The public health exemption. For example, in June 1979, the California Department of Health Services was permitted to use DDT to suppress flea vectors of bubonic plague . DDT continued to be produced in the United States for foreign markets until 1985, when over 300 tons were exported. In the 1970s and 1980s, agricultural use was banned in most developed countries, beginning with Hungary in 1968 – although in practice it continued to be used through at least 1970. This

4312-581: The pyrethrum was harder to access since it came mainly from Japan. Due to the potency of DDT, it was not long before America's War Production Board placed it on military supply lists in 1942 and 1943 and encouraged its production for overseas use. Enthusiasm regarding DDT became obvious through the American government's advertising campaigns of posters depicting Americans fighting the Axis powers and insects and through media publications celebrating its military uses. In

4389-508: The region's food web . Medical researchers in 1974 found a measurable and significant difference in the presence of DDT in human milk between mothers who lived in New Brunswick and mothers who lived in Nova Scotia , "possibly because of the wider use of insecticide sprays in the past". Because of its lipophilic properties, DDT can bioaccumulate , especially in predatory birds . DDT

4466-471: The same time that DDT was hailed as part of the "world of tomorrow", concerns were expressed about its potential to kill harmless and beneficial insects (particularly pollinators ), birds, fish, and eventually humans. The issue of toxicity was complicated, partly because DDT's effects varied from species to species, and partly because consecutive exposures could accumulate, causing damage comparable to large doses. A number of states attempted to regulate DDT. In

4543-418: The shell gland and reduces the transport of calcium carbonate from blood into the eggshell gland. This results in a dose-dependent thickness reduction. Other evidence indicates that o,p'-DDT disrupts female reproductive tract development, later impairing eggshell quality. Multiple mechanisms may be at work, or different mechanisms may operate in different species. DDT is an endocrine disruptor . It

4620-403: The specific goal of enacting a ban on DDT. Victor Yannacone , Charles F. Wurster , Art Cooley and others in the group had all witnessed bird kills or declines in bird populations and suspected that DDT was the cause. In their campaign against the chemical, the EDF petitioned the government for a ban and filed lawsuits. Around this time, toxicologist David Peakall was measuring DDE levels in

4697-526: The summer of 1972, Ruckelshaus announced the cancellation of most uses of DDT – exempting public health uses under some conditions. Again, this caused controversy. Immediately after the announcement, both the EDF and the DDT manufacturers filed suit against EPA. Many in the agricultural community were concerned that food production would be severely impacted, while proponents of pesticides warned of increased breakouts of insect-borne diseases and questioned

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4774-671: The treatment of interior walls and ceilings with insecticides. It is particularly effective against mosquitoes, since many species rest on an indoor wall before or after feeding. DDT is one of 12 WHO–approved IRS insecticides. The WHO's anti-malaria campaign of the 1950s and 1960s relied heavily on DDT and the results were promising, though temporary in developing countries. Experts tie malarial resurgence to multiple factors, including poor leadership, management and funding of malaria control programs; poverty; civil unrest; and increased irrigation . The evolution of resistance to first-generation drugs (e.g. chloroquine ) and to insecticides exacerbated

4851-538: The treaty is arguably better than the status quo going into the negotiations. For the first time, there is now an insecticide which is restricted to vector control only, meaning that the selection of resistant mosquitoes will be slower than before." Despite the worldwide ban, agricultural use continued in India, North Korea, and possibly elsewhere. As of 2013, an estimated 3,000 to 4,000 tons of DDT were produced for disease vector control , including 2,786 tons in India. DDT

4928-537: The water (however, its half-life in aquatic environments is listed by the National Pesticide Information Center as 150 years ). Its breakdown products and metabolites, DDE and DDD, are also persistent and have similar chemical and physical properties. DDT and its breakdown products are transported from warmer areas to the Arctic by the phenomenon of global distillation , where they then accumulate in

5005-405: The waters of bayous bioaccumulates in organisms to spread their toxins throughout various trophic levels. This harms both the health of individuals in that ecosystem as well as the humans who would be ingesting fish and other aquatic organisms with potential metal contamination. Anabranch An anabranch is a section of a river or stream that diverts from the main channel or stem of

5082-686: The watershed. Many bayous have been cleared away by human activity as well (with those in Louisiana having shrunk by 1,900 square miles; 4,900 square kilometers since the 1930s). Farming activities introduce nutrients into bayou ecosystems. Row crop agricultural land use is common (75–86% of the bayou watershed) in Bayou watersheds given the unique physical characteristics like flat topography and alluvial soils. Agricultural activity results in byproducts of nitrogen and phosphorus from fertilizers, which can drastically alter delicate balances in freshwater and marine ecosystems. A study conducted on 3 agricultural bayous in

5159-500: The western Mississippi River watershed found that pesticides released into bayou sediments cause significant impairment of the amphipod Hyalella azteca both spatially and temporally. Despite being banned 40 years ago in the United States by the Environmental Protection Agency, traces of dichlorodiphenyltrichloroethane ( DDT ), once used in agriculture as an insecticide, were found in sediment and amphipod tissue. DDT

5236-478: The words of the journal Science , and recommended a phaseout of "persistent toxic pesticides". In 1965, the U.S. military removed DDT from the military supply system due in part to the development of resistance by body lice to DDT; it was replaced by lindane . DDT became a prime target of the growing anti-chemical and anti-pesticide movements, and in 1967 a group of scientists and lawyers founded Environmental Defense (later Environmental Defense Fund, EDF) with

5313-466: Was a threat to wildlife, particularly birds. Although Carson never directly called for an outright ban on the use of DDT, its publication was a seminal event for the environmental movement and resulted in a large public outcry that eventually led, in 1972, to a ban on DDT's agricultural use in the United States. Along with the passage of the Endangered Species Act , the United States ban on DDT

5390-418: Was abandoned in 1969 and attention instead focused on controlling and treating the disease. Spraying programs (especially using DDT) were curtailed due to concerns over safety and environmental effects, as well as problems in administrative, managerial and financial implementation. Efforts shifted from spraying to the use of bednets impregnated with insecticides and other interventions. By October 1945, DDT

5467-449: Was applied in sub-Saharan Africa by various colonial states, but the 'global' WHO eradication program didn't include the region. Mortality rates in that area never declined to the same dramatic extent, and now constitute the bulk of malarial deaths worldwide, especially following the disease's resurgence as a result of resistance to drug treatments and the spread of the deadly malarial variant caused by Plasmodium falciparum . Eradication

5544-502: Was available for public sale in the United States, used both as an agricultural pesticide and as a household insecticide. Although its use was promoted by government and the agricultural industry, US scientists such as FDA pharmacologist Herbert O. Calvery expressed concern over possible hazards associated with DDT as early as 1944. In 1947, Bradbury Robinson , a physician and nutritionist practicing in St. Louis, Michigan , warned of

5621-515: Was extensively used in agriculture – more than 40,000 tonnes each year worldwide  – and it has been estimated that a total of 1.8 million tonnes have been produced globally since the 1940s. In the United States, it was manufactured by some 15 companies, including Monsanto , Ciba , Montrose Chemical Company , Pennwalt , and Velsicol Chemical Corporation . Production peaked in 1963 at 82,000 tonnes per year. More than 600,000 tonnes (1.35 billion pounds) were applied in

5698-637: Was first conclusively proven at Bellow Island in Lake Michigan during University of Michigan -funded studies on American herring gulls in the mid-1960s. DDE-related eggshell thinning is considered a major reason for the decline of the bald eagle , brown pelican , peregrine falcon and osprey . However, birds vary in their sensitivity to these chemicals, with birds of prey , waterfowl and song birds being more susceptible than chickens and related species . Even in 2010, California condors that feed on sea lions at Big Sur that in turn feed in

5775-559: Was first synthesized in 1874 by the Austrian chemist Othmar Zeidler . DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT was used in the second half of World War II to limit the spread of the insect-borne diseases malaria and typhus among civilians and troops. Müller was awarded the Nobel Prize in Physiology or Medicine in 1948 "for his discovery of

5852-620: Was followed by Norway and Sweden in 1970, West Germany and the United States in 1972, but not in the United Kingdom until 1984. In contrast to West Germany, in the German Democratic Republic DDT was used until 1988. Especially of relevance were large-scale applications in forestry in the years 1982–1984, with the aim to combat bark beetle and pine moth . As a consequence, DDT-concentrations in eastern German forest soils are still significantly higher compared to soils in

5929-614: Was ratified by more than 170 countries. Recognizing that total elimination in many malaria-prone countries is currently unfeasible in the absence of affordable/effective alternatives, the convention exempts public health use within World Health Organization (WHO) guidelines from the ban. Resolution 60.18 of the World Health Assembly commits WHO to the Stockholm Convention's aim of reducing and ultimately eliminating DDT. Malaria Foundation International states, "The outcome of

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