This document provides information about tributyltin (TBT) compounds, specifically tributyltin oxide (TBTO). It discusses that TBTO is a common organotin compound used as a biocide in antifouling paints for boats. While an effective biocide, concerns about its toxicity and bioaccumulation in food chains have led to increased regulations and bans on its use. TBTO is toxic to aquatic organisms and high levels of exposure in humans can cause skin, eye and respiratory irritation along with organ damage. Most regulations on TBTO arose from cases of sexual abnormalities in snail species and now aim to decrease its use in antifouling paints.
Tributyltin compounds are used as biocides and in antifouling paints. They are toxic to both humans and marine environments. Tributyltin compounds cause reproductive and developmental toxicity in mammals and imposex in mollusks. Due to these effects, their use has been regulated and banned in many applications.
The document summarizes an insect toxicology presentation about insecticide mode of action. It discusses how understanding mode of action can optimize insecticide use and increase safety. It then provides examples of common insecticide classes like organophosphates, pyrethroids, neonicotinoids and their target sites in the nervous system. Safety tips are given to read labels and use less toxic products.
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
role of contact fungicides in the management of phytopathogens Satendra Shroti
This document provides an overview of contact fungicides and their role in managing phytopathogens. It begins with an introduction to contact fungicides and their characteristics such as remaining on plant surfaces and not being systemic. The document then covers the classification, history, modes of action, and application of various contact fungicide types including copper, sulfur, and heterocyclic nitrogenous compounds. Safety precautions for operators are also mentioned.
Pheromone traps use insects' pheromones to attract them. Releasing natural enemies like frogs is a form of biological pest control. Tobacco and neem extracts are common organic pesticides, while chemical pesticides like Furadan and DDT cause environmental problems, though they are widely used.
Degradation of Propranolol by Photo Catalysis -Poster-1Jorge Isaac Valent
This document summarizes a study on the degradation of the pharmaceutical propranolol by photocatalysis using titanium dioxide. The researchers tested different pH levels and TiO2 concentrations and found that a pH between 4-6.3 and a TiO2 concentration of 0.7 g/L provided the best degradation of propranolol. They also found that reducing the solution volume from 400ml to 200ml improved degradation yields. The goal was to evaluate TiO2's ability to degrade propranolol via photocatalysis and determine optimal conditions for higher reaction rates.
Effect of some cover crops and their secondary metabolites on nitrous oxide (...Agriculture Journal IJOEAR
Abstract—Using a Pseudomonas denitrifying bacterium, which had been isolated from Japanese Andisol corn farm as an active nitrous oxide (N2O) emitter and likely to be missing nosZ gene, we investigated denitrification-regulating activity of some cover crops or green manure plants against this N2O emitter. In the preliminary screening, root exudates from the 10 seedlings of yellow flowering leaf mustard (Brassica juncea) and crimson clover (Trifolium incarnatum) showed 50% repression of the N2O emission by an incomplete denitrifier Pseudomonas sp. 05CFM15-6D. When direct extracts of the seedling roots with MeOH were assayed, however, only the seedlings of B. juncea showed a remarkable inhibition of bacterial cell growth and N2O emission at concentration equivalent to 10 seedlings. The root extract from B. juncea equivalent to 2 to 4 seedlings maintained inhibiting activity toward N2O emission, while it did not affect bacterial cell growth. Conversely, water-soluble fraction from aboveground of European small radish (Raphanus sativus var. sativus) sprouts showed statistically significant acceleration of N2O emission (P<0.01) with slight but insignificant cell growth activation. As some secondary metabolites are uniquely contained in these cover crops, suppressing or accelerating activity of such phytochemicals in N2O emission was also investigated. Allyl isothiocyanate at 30 µM markedly inhibited N2O emission of the Pseudomonas denitrifier but not suppressed its cell growth. In contrast, methyl isothiocyanate sinigrin, cyanamide, and betanin did not affect on N2O emission of the denitrifier at 150-300 µM.
This document discusses persistent organic pollutants (POPs). It begins by introducing the topic and defining POPs as the most problematic group of chemicals that are produced worldwide in large quantities and persist in the environment. It then details the "dirty dozen" POPs, their categories and historic uses. The document discusses how POPs are distributed globally and concentrated in cold regions. It outlines the main routes of human exposure and concepts of bioaccumulation and biomagnification in food chains. It explains dose-response curves and gives examples of POP contamination in food. Finally, it summarizes the history and objectives of the Stockholm Convention which aims to eliminate or restrict POPs internationally.
Tributyltin compounds are used as biocides and in antifouling paints. They are toxic to both humans and marine environments. Tributyltin compounds cause reproductive and developmental toxicity in mammals and imposex in mollusks. Due to these effects, their use has been regulated and banned in many applications.
The document summarizes an insect toxicology presentation about insecticide mode of action. It discusses how understanding mode of action can optimize insecticide use and increase safety. It then provides examples of common insecticide classes like organophosphates, pyrethroids, neonicotinoids and their target sites in the nervous system. Safety tips are given to read labels and use less toxic products.
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
role of contact fungicides in the management of phytopathogens Satendra Shroti
This document provides an overview of contact fungicides and their role in managing phytopathogens. It begins with an introduction to contact fungicides and their characteristics such as remaining on plant surfaces and not being systemic. The document then covers the classification, history, modes of action, and application of various contact fungicide types including copper, sulfur, and heterocyclic nitrogenous compounds. Safety precautions for operators are also mentioned.
Pheromone traps use insects' pheromones to attract them. Releasing natural enemies like frogs is a form of biological pest control. Tobacco and neem extracts are common organic pesticides, while chemical pesticides like Furadan and DDT cause environmental problems, though they are widely used.
Degradation of Propranolol by Photo Catalysis -Poster-1Jorge Isaac Valent
This document summarizes a study on the degradation of the pharmaceutical propranolol by photocatalysis using titanium dioxide. The researchers tested different pH levels and TiO2 concentrations and found that a pH between 4-6.3 and a TiO2 concentration of 0.7 g/L provided the best degradation of propranolol. They also found that reducing the solution volume from 400ml to 200ml improved degradation yields. The goal was to evaluate TiO2's ability to degrade propranolol via photocatalysis and determine optimal conditions for higher reaction rates.
Effect of some cover crops and their secondary metabolites on nitrous oxide (...Agriculture Journal IJOEAR
Abstract—Using a Pseudomonas denitrifying bacterium, which had been isolated from Japanese Andisol corn farm as an active nitrous oxide (N2O) emitter and likely to be missing nosZ gene, we investigated denitrification-regulating activity of some cover crops or green manure plants against this N2O emitter. In the preliminary screening, root exudates from the 10 seedlings of yellow flowering leaf mustard (Brassica juncea) and crimson clover (Trifolium incarnatum) showed 50% repression of the N2O emission by an incomplete denitrifier Pseudomonas sp. 05CFM15-6D. When direct extracts of the seedling roots with MeOH were assayed, however, only the seedlings of B. juncea showed a remarkable inhibition of bacterial cell growth and N2O emission at concentration equivalent to 10 seedlings. The root extract from B. juncea equivalent to 2 to 4 seedlings maintained inhibiting activity toward N2O emission, while it did not affect bacterial cell growth. Conversely, water-soluble fraction from aboveground of European small radish (Raphanus sativus var. sativus) sprouts showed statistically significant acceleration of N2O emission (P<0.01) with slight but insignificant cell growth activation. As some secondary metabolites are uniquely contained in these cover crops, suppressing or accelerating activity of such phytochemicals in N2O emission was also investigated. Allyl isothiocyanate at 30 µM markedly inhibited N2O emission of the Pseudomonas denitrifier but not suppressed its cell growth. In contrast, methyl isothiocyanate sinigrin, cyanamide, and betanin did not affect on N2O emission of the denitrifier at 150-300 µM.
This document discusses persistent organic pollutants (POPs). It begins by introducing the topic and defining POPs as the most problematic group of chemicals that are produced worldwide in large quantities and persist in the environment. It then details the "dirty dozen" POPs, their categories and historic uses. The document discusses how POPs are distributed globally and concentrated in cold regions. It outlines the main routes of human exposure and concepts of bioaccumulation and biomagnification in food chains. It explains dose-response curves and gives examples of POP contamination in food. Finally, it summarizes the history and objectives of the Stockholm Convention which aims to eliminate or restrict POPs internationally.
Rotenone is a naturally occurring pesticide extracted from plant roots and stems. It works by interfering with electron transport in mitochondria, inhibiting energy production and creating reactive oxygen species. Rotenone is highly toxic to aquatic life and insects but only mildly toxic to humans. It has been used historically as a pesticide and piscicide by indigenous groups and is still used commercially and privately in some applications.
structure and toxicity of pyrethroid slideshareishitamaji
This document discusses the structure, evolution, and toxicity of pyrethroid pesticides to aquatic animals. It describes how pyrethroids are classified into Type I and Type II compounds based on their structure and toxicology. Type II pyrethroids containing an alpha-cyano group are more potent neurotoxins that can cause acute toxicity in fish as well as hematological and biochemical changes by disrupting acetylcholine esterase levels and enzymes like lactate dehydrogenase. The document reviews studies examining the effects of various Type II pyrethroids like deltamethrin, cypermethrin, and fenvalerate on different fish species.
M.Sc. (Master's) Seminar on topic "Role of chemicals in plant disease managem...Harshvardhan Gaikwad
The importance and role of chemicals/ fungicides in plant disease management is the major objective of plant pathology. The need based, effective, ecofriendly application of chemical fungicides can leads sustainable agriculture and food production.
Rotenone is a natural pesticide extracted from the roots and stems of several tropical plant species. It works by interfering with electron transport in mitochondria, which inhibits ATP production and creates reactive oxygen species. Rotenone has been used historically by indigenous groups to catch fish and is also used as an insecticide, though it is toxic to aquatic life and insects. While mildly toxic to humans, rotenone poisoning can be fatal with high doses and it degrades when exposed to sunlight.
pesticides and organophosphate poisoining.Sampath Sai
This document provides information about pesticidal poisoning by organophosphates. It defines pesticides and organophosphates, and describes their classification and common examples. It then discusses the potential health effects of organophosphate poisoning, including endocrine damage, cancers, nervous system damage, and more. The document outlines the mechanisms of action, signs and symptoms, investigations and management of organophosphate poisoning. Key aspects of management include decontamination, atropine administration to reverse muscarinic effects, pralidoxime administration to reactivate cholinesterase and reverse nicotinic effects, and supportive care.
A bacterium that degrades and assimilates poly(ethylene terephthalate)Md. Shabab Mehebub
A new bacteria that able to breakdown and assimilates PET. It was a great discovery. We made a powerpoint presentation on that research paper. It was great challenge for us...
Phenolic compounds play an important role in plant defense. They accumulate at infection sites and have antimicrobial properties. Their biosynthesis occurs through the shikimate pathway. Key enzymes like PAL and polyphenol oxidases are involved. Phenolics act as UV screens, signals, pigments, and help growth and defense. Phytoanticipins are preformed while phytoalexins are induced after infection. Case studies showed phenolics increased in response to pathogens and some like naringin and tangeretin had antifungal properties against Penicillium digitatum.
This document discusses microbial epoxide hydrolases. It begins by defining epoxides and their roles in various metabolic processes and as signaling molecules. It then describes the different types of epoxide hydrolases that control epoxide production, including soluble epoxide hydrolase and microbial epoxide hydrolase. Approximately 20% of microorganisms possess epoxide hydrolase genes. Microbial epoxide hydrolases are involved in detoxifying xenobiotic compounds and metabolizing limonene. They also have applications in synthesizing pharmaceutical intermediates and treating conditions like tuberculosis and cystic fibrosis.
Secondary metabolites are chemicals produced by plants that are not essential for primary functions like growth, photosynthesis or reproduction. They include a wide variety of compounds classified by chemical structure or pathway. Many secondary metabolites help defend plants from herbivores and pathogens. Some have uses as medicines, flavors or recreational drugs and influence plant interactions with other organisms.
The document discusses xenobiotics, which are foreign compounds found within an organism that are not naturally produced or expected to be present. It describes how xenobiotics are produced artificially for industrial purposes and how natural substances can also become xenobiotics. It then discusses the origins of different types of xenobiotic compounds from various industries. It notes hazards posed by xenobiotics like resistance to degradation and toxicity. Methods for remediating xenobiotics are explored, including photodegradation, bioremediation, phytoremediation, and genetic engineering of plants for remediation.
Synthetic Pyrethroids are widely used insecticides with wide range from applications apart from agricultural, like household insecticides, veterinary use and medicinal use. Presentation here covers every possible aspect right from discovery to most recent development in the field of Pyrethroids.
Two research articles on pesticides in cambodia 2011 02 28 vs 07 2011Scheewe
Brief discussion of the implication of two articles concerning pesticide use in vegetable production in Cambodia and effects on pesticide resiues in market vegetables.
effect of gases on vegetable productionRicha Naula
Elevated levels of carbon dioxide, sulfur dioxide, nitrogen dioxide, and ozone in the atmosphere can impact the growth and yield of plants. Carbon dioxide acts as a nutrient for plants and increases photosynthesis, but other gases like sulfur dioxide and nitrogen dioxide can reduce plant growth and damage leaves at high concentrations. Ozone is also phytotoxic and causes leaf injury in crops like tomato, spinach, and radish. Studies have shown that elevated carbon dioxide can increase plant biomass and yield of some vegetables like tomato, while air pollutants decrease these parameters. The effects of gases depend on the concentration and duration of exposure.
This document defines fungicides and related terms like fungistat and antisporulant. It classifies fungicides based on their mode of action (protectant, therapeutant, eradicatcant), general use (seed protectants, soil fungicides, foliage fungicides), and chemical composition (sulphur fungicides, copper fungicides, dithiocarbamates). Specific examples are provided for each classification along with the diseases they control.
formation of phenolic compounds in plants during air pollution Nihariká Singh
Phenolic compounds are a group of defense compounds synthesized by plants in response to stress from air pollution. When plants are exposed to air pollutants like SO2, NO2, and O3, there is an increase in phenolic compound production. Phenolic compounds accumulate in plant tissues and compartments like vacuoles and cell walls. This accumulation can lead to cell damage and necrosis. The increased production of phenolic compounds helps protect plants from damage by oxidative stress caused by air pollutants.
Oxidative treatment of high explosives contaminated wastewaterRaafat Alnaizy, PhD
1) The document discusses methods for treating wastewater contaminated with high explosives (HE) such as TNT, RDX, and HMX through catalytic/non-catalytic wet oxidation and advanced oxidation processes using ultraviolet light and hydrogen peroxide.
2) Catalytic and non-catalytic wet oxidation experiments were conducted in a batch reactor at moderate pressures and temperatures using a Pt/TiO2 catalyst.
3) Ultraviolet photolysis experiments alone and in combination with hydrogen peroxide were carried out in a glass photoreactor at ambient conditions using a low-pressure mercury lamp.
This document provides information on the chemistry of various classes of pesticides, including their structure, synthesis, mode of action, and uses. It discusses organochlorines like DDT and lindane, organophosphates such as malathion and parathion, carbamates including carbaryl and carbofuran, and quinone pesticides. For each class, examples are given of their preparation and the biological effects of inhibiting important enzymes in insects, such as cholinesterase for organophosphates and carbamates. A variety of natural and synthetic pesticides are also mentioned.
Neurotoxins are substances that are toxic to nerve cells. They can originate from plants, animals, minerals, or the atmosphere. Common neurotoxins include botulinum toxin, tetrodotoxin, and toxic metals like mercury and lead. Botulinum toxin, produced by Clostridium botulinum bacteria, is the most potent toxin known and works by inhibiting the release of acetylcholine at neuromuscular junctions, causing paralysis. Tetrodotoxin blocks sodium channels, leading to paralysis and respiratory failure. Heavy metals like mercury and lead can cross the blood-brain barrier and cause central nervous system damage. While some neurotoxins like glutamate and nitric oxide are normally present in the body, higher concentrations can
TNT is a common explosive that has contaminated many sites. Bioremediation uses microorganisms and plants to break down TNT into less harmful substances. There are three main bioremediation processes - composting mixes contaminated soil with bulking agents to promote microbial degradation of TNT over time; bioslurries use tanks of soil, microbes, and nutrients to intensively degrade TNT; and phytoremediation uses plant roots and associated microbes to immobilize or degrade TNT in contaminated areas. Compared to incineration, bioremediation provides a more cost-effective and environmentally friendly means of removing TNT contamination from soil.
Toxic Effects of the Easily Avoidable Phthalates and Parabensv2zq
This document summarizes research on the health effects of phthalates and parabens. It finds that while phthalates and parabens are rapidly cleared from the body, daily exposure through common consumer products can pose health risks. Phthalates are widely used plasticizers found in many personal care products, food packaging, and medical supplies. Studies have linked several phthalates to infertility, birth defects, obesity, asthma, and cancer. Parabens are preservatives used in cosmetics that are absorbed through the skin and may increase breast cancer risk. The document recommends avoiding phthalate and paraben containing products to reduce exposure and health risks.
This document discusses trinitrotoluene (TNT), an explosive used widely in military applications. It provides background on TNT, noting its production beginning in the late 19th century for military use. Large-scale production has led to pollution at munitions factory sites. The document outlines impacts of TNT exposure on living organisms and various bioremediation methods for TNT-contaminated soils, including composting, bioslurries, and phytoremediation. Composting and bioslurries use microbes to break down TNT, while plants may also degrade or immobilize TNT through phytoremediation. Bioremediation provides a less expensive alternative to incin
Foods deteriorate in quality due to a wide range of reactions .docxkeugene1
Foods deteriorate in quality due to a wide range of reactions including some that are
physical, some that are chemical, some enzymatic and some microbiological. The various
forms of spoilage and food poisoning caused by microorganisms are preventable to a large
degree by a number of preservation techniques, most of which act by preventing or slowing
microbial growth. These include freezing, chilling, drying, curing, conserving, vacuum
packing, modified atmosphere packing, acidifying, fermenting, and adding chemical
preservatives. This is section 13, Chemical food protection. We’ll look at the other food
preservation mechanisms in future modules.
1
From the moment a food source is harvested in begins to deteriorate. It is estimated that
25% of the worlds food is lost to microbial decay annually. This equals more than a billion
dollars per year.
2
Salting as a means of preserving foods predates written history. The Mesopotamians were
known 3000 B.C.E. generally used salt to preserve meat and fish. Early Roman writers such
as Cato (234‐149 B.C.E.) clearly explained the need to salt perishable meats and vegetables
to preserve them. We have already seen in past chapters that salt binds water reducing
water activity and also is toxic to enzymatic and DNA processes in cells.
3
Today, nearly all manufactured foods have different chemical preservatives because it
makes financial sense. Food additives maintain or improve freshness, safety, nutritional
value, taste, texture, or appearance. Consumers demand and enjoy a food supply that is
flavorful, nutritious, safe, convenient, colorful and affordable.
4
No audio.
5
No audio.
6
In the United States, neither the Food and Drug Administration (FDA) nor the U.S.
Department of Agriculture (USDA) has labeling claim rules for “natural." The FDA explicitly
discourages the food industry from using the term. The Food, Drug, and Cosmetic Act
prohibits labeling that is false or misleading, but does not give any specifics. The USDA's
Agricultural Marketing Service has a standard for organic food, but there is no legal
definition for natural foods. Despite no legal U.S. definition for natural foods, there are
numerous unofficial or informal definitions, none of which are applied uniformly to foods
labeled "natural".
7
So, are food chemical additives safe?
8
In 1958, the US created food additive legislation stating that the FDA must approve all food
additives and ingredients that are not generally recognized as safe. The GRAS list contains
food additives that have been used historically and have shown no hazards during that
time. Easily recognized examples are sodium chloride, sucrose and acetic acid. Less easily
recognized are many of the common food preservatives such as sodium benzoate,
potassium sorbate, and calcium propionate.
9
The U.S. FDA maintains a list of over 3000 approved, generally recognized as safe, food
ingredients including food.
Rotenone is a naturally occurring pesticide extracted from plant roots and stems. It works by interfering with electron transport in mitochondria, inhibiting energy production and creating reactive oxygen species. Rotenone is highly toxic to aquatic life and insects but only mildly toxic to humans. It has been used historically as a pesticide and piscicide by indigenous groups and is still used commercially and privately in some applications.
structure and toxicity of pyrethroid slideshareishitamaji
This document discusses the structure, evolution, and toxicity of pyrethroid pesticides to aquatic animals. It describes how pyrethroids are classified into Type I and Type II compounds based on their structure and toxicology. Type II pyrethroids containing an alpha-cyano group are more potent neurotoxins that can cause acute toxicity in fish as well as hematological and biochemical changes by disrupting acetylcholine esterase levels and enzymes like lactate dehydrogenase. The document reviews studies examining the effects of various Type II pyrethroids like deltamethrin, cypermethrin, and fenvalerate on different fish species.
M.Sc. (Master's) Seminar on topic "Role of chemicals in plant disease managem...Harshvardhan Gaikwad
The importance and role of chemicals/ fungicides in plant disease management is the major objective of plant pathology. The need based, effective, ecofriendly application of chemical fungicides can leads sustainable agriculture and food production.
Rotenone is a natural pesticide extracted from the roots and stems of several tropical plant species. It works by interfering with electron transport in mitochondria, which inhibits ATP production and creates reactive oxygen species. Rotenone has been used historically by indigenous groups to catch fish and is also used as an insecticide, though it is toxic to aquatic life and insects. While mildly toxic to humans, rotenone poisoning can be fatal with high doses and it degrades when exposed to sunlight.
pesticides and organophosphate poisoining.Sampath Sai
This document provides information about pesticidal poisoning by organophosphates. It defines pesticides and organophosphates, and describes their classification and common examples. It then discusses the potential health effects of organophosphate poisoning, including endocrine damage, cancers, nervous system damage, and more. The document outlines the mechanisms of action, signs and symptoms, investigations and management of organophosphate poisoning. Key aspects of management include decontamination, atropine administration to reverse muscarinic effects, pralidoxime administration to reactivate cholinesterase and reverse nicotinic effects, and supportive care.
A bacterium that degrades and assimilates poly(ethylene terephthalate)Md. Shabab Mehebub
A new bacteria that able to breakdown and assimilates PET. It was a great discovery. We made a powerpoint presentation on that research paper. It was great challenge for us...
Phenolic compounds play an important role in plant defense. They accumulate at infection sites and have antimicrobial properties. Their biosynthesis occurs through the shikimate pathway. Key enzymes like PAL and polyphenol oxidases are involved. Phenolics act as UV screens, signals, pigments, and help growth and defense. Phytoanticipins are preformed while phytoalexins are induced after infection. Case studies showed phenolics increased in response to pathogens and some like naringin and tangeretin had antifungal properties against Penicillium digitatum.
This document discusses microbial epoxide hydrolases. It begins by defining epoxides and their roles in various metabolic processes and as signaling molecules. It then describes the different types of epoxide hydrolases that control epoxide production, including soluble epoxide hydrolase and microbial epoxide hydrolase. Approximately 20% of microorganisms possess epoxide hydrolase genes. Microbial epoxide hydrolases are involved in detoxifying xenobiotic compounds and metabolizing limonene. They also have applications in synthesizing pharmaceutical intermediates and treating conditions like tuberculosis and cystic fibrosis.
Secondary metabolites are chemicals produced by plants that are not essential for primary functions like growth, photosynthesis or reproduction. They include a wide variety of compounds classified by chemical structure or pathway. Many secondary metabolites help defend plants from herbivores and pathogens. Some have uses as medicines, flavors or recreational drugs and influence plant interactions with other organisms.
The document discusses xenobiotics, which are foreign compounds found within an organism that are not naturally produced or expected to be present. It describes how xenobiotics are produced artificially for industrial purposes and how natural substances can also become xenobiotics. It then discusses the origins of different types of xenobiotic compounds from various industries. It notes hazards posed by xenobiotics like resistance to degradation and toxicity. Methods for remediating xenobiotics are explored, including photodegradation, bioremediation, phytoremediation, and genetic engineering of plants for remediation.
Synthetic Pyrethroids are widely used insecticides with wide range from applications apart from agricultural, like household insecticides, veterinary use and medicinal use. Presentation here covers every possible aspect right from discovery to most recent development in the field of Pyrethroids.
Two research articles on pesticides in cambodia 2011 02 28 vs 07 2011Scheewe
Brief discussion of the implication of two articles concerning pesticide use in vegetable production in Cambodia and effects on pesticide resiues in market vegetables.
effect of gases on vegetable productionRicha Naula
Elevated levels of carbon dioxide, sulfur dioxide, nitrogen dioxide, and ozone in the atmosphere can impact the growth and yield of plants. Carbon dioxide acts as a nutrient for plants and increases photosynthesis, but other gases like sulfur dioxide and nitrogen dioxide can reduce plant growth and damage leaves at high concentrations. Ozone is also phytotoxic and causes leaf injury in crops like tomato, spinach, and radish. Studies have shown that elevated carbon dioxide can increase plant biomass and yield of some vegetables like tomato, while air pollutants decrease these parameters. The effects of gases depend on the concentration and duration of exposure.
This document defines fungicides and related terms like fungistat and antisporulant. It classifies fungicides based on their mode of action (protectant, therapeutant, eradicatcant), general use (seed protectants, soil fungicides, foliage fungicides), and chemical composition (sulphur fungicides, copper fungicides, dithiocarbamates). Specific examples are provided for each classification along with the diseases they control.
formation of phenolic compounds in plants during air pollution Nihariká Singh
Phenolic compounds are a group of defense compounds synthesized by plants in response to stress from air pollution. When plants are exposed to air pollutants like SO2, NO2, and O3, there is an increase in phenolic compound production. Phenolic compounds accumulate in plant tissues and compartments like vacuoles and cell walls. This accumulation can lead to cell damage and necrosis. The increased production of phenolic compounds helps protect plants from damage by oxidative stress caused by air pollutants.
Oxidative treatment of high explosives contaminated wastewaterRaafat Alnaizy, PhD
1) The document discusses methods for treating wastewater contaminated with high explosives (HE) such as TNT, RDX, and HMX through catalytic/non-catalytic wet oxidation and advanced oxidation processes using ultraviolet light and hydrogen peroxide.
2) Catalytic and non-catalytic wet oxidation experiments were conducted in a batch reactor at moderate pressures and temperatures using a Pt/TiO2 catalyst.
3) Ultraviolet photolysis experiments alone and in combination with hydrogen peroxide were carried out in a glass photoreactor at ambient conditions using a low-pressure mercury lamp.
This document provides information on the chemistry of various classes of pesticides, including their structure, synthesis, mode of action, and uses. It discusses organochlorines like DDT and lindane, organophosphates such as malathion and parathion, carbamates including carbaryl and carbofuran, and quinone pesticides. For each class, examples are given of their preparation and the biological effects of inhibiting important enzymes in insects, such as cholinesterase for organophosphates and carbamates. A variety of natural and synthetic pesticides are also mentioned.
Neurotoxins are substances that are toxic to nerve cells. They can originate from plants, animals, minerals, or the atmosphere. Common neurotoxins include botulinum toxin, tetrodotoxin, and toxic metals like mercury and lead. Botulinum toxin, produced by Clostridium botulinum bacteria, is the most potent toxin known and works by inhibiting the release of acetylcholine at neuromuscular junctions, causing paralysis. Tetrodotoxin blocks sodium channels, leading to paralysis and respiratory failure. Heavy metals like mercury and lead can cross the blood-brain barrier and cause central nervous system damage. While some neurotoxins like glutamate and nitric oxide are normally present in the body, higher concentrations can
TNT is a common explosive that has contaminated many sites. Bioremediation uses microorganisms and plants to break down TNT into less harmful substances. There are three main bioremediation processes - composting mixes contaminated soil with bulking agents to promote microbial degradation of TNT over time; bioslurries use tanks of soil, microbes, and nutrients to intensively degrade TNT; and phytoremediation uses plant roots and associated microbes to immobilize or degrade TNT in contaminated areas. Compared to incineration, bioremediation provides a more cost-effective and environmentally friendly means of removing TNT contamination from soil.
Toxic Effects of the Easily Avoidable Phthalates and Parabensv2zq
This document summarizes research on the health effects of phthalates and parabens. It finds that while phthalates and parabens are rapidly cleared from the body, daily exposure through common consumer products can pose health risks. Phthalates are widely used plasticizers found in many personal care products, food packaging, and medical supplies. Studies have linked several phthalates to infertility, birth defects, obesity, asthma, and cancer. Parabens are preservatives used in cosmetics that are absorbed through the skin and may increase breast cancer risk. The document recommends avoiding phthalate and paraben containing products to reduce exposure and health risks.
This document discusses trinitrotoluene (TNT), an explosive used widely in military applications. It provides background on TNT, noting its production beginning in the late 19th century for military use. Large-scale production has led to pollution at munitions factory sites. The document outlines impacts of TNT exposure on living organisms and various bioremediation methods for TNT-contaminated soils, including composting, bioslurries, and phytoremediation. Composting and bioslurries use microbes to break down TNT, while plants may also degrade or immobilize TNT through phytoremediation. Bioremediation provides a less expensive alternative to incin
Foods deteriorate in quality due to a wide range of reactions .docxkeugene1
Foods deteriorate in quality due to a wide range of reactions including some that are
physical, some that are chemical, some enzymatic and some microbiological. The various
forms of spoilage and food poisoning caused by microorganisms are preventable to a large
degree by a number of preservation techniques, most of which act by preventing or slowing
microbial growth. These include freezing, chilling, drying, curing, conserving, vacuum
packing, modified atmosphere packing, acidifying, fermenting, and adding chemical
preservatives. This is section 13, Chemical food protection. We’ll look at the other food
preservation mechanisms in future modules.
1
From the moment a food source is harvested in begins to deteriorate. It is estimated that
25% of the worlds food is lost to microbial decay annually. This equals more than a billion
dollars per year.
2
Salting as a means of preserving foods predates written history. The Mesopotamians were
known 3000 B.C.E. generally used salt to preserve meat and fish. Early Roman writers such
as Cato (234‐149 B.C.E.) clearly explained the need to salt perishable meats and vegetables
to preserve them. We have already seen in past chapters that salt binds water reducing
water activity and also is toxic to enzymatic and DNA processes in cells.
3
Today, nearly all manufactured foods have different chemical preservatives because it
makes financial sense. Food additives maintain or improve freshness, safety, nutritional
value, taste, texture, or appearance. Consumers demand and enjoy a food supply that is
flavorful, nutritious, safe, convenient, colorful and affordable.
4
No audio.
5
No audio.
6
In the United States, neither the Food and Drug Administration (FDA) nor the U.S.
Department of Agriculture (USDA) has labeling claim rules for “natural." The FDA explicitly
discourages the food industry from using the term. The Food, Drug, and Cosmetic Act
prohibits labeling that is false or misleading, but does not give any specifics. The USDA's
Agricultural Marketing Service has a standard for organic food, but there is no legal
definition for natural foods. Despite no legal U.S. definition for natural foods, there are
numerous unofficial or informal definitions, none of which are applied uniformly to foods
labeled "natural".
7
So, are food chemical additives safe?
8
In 1958, the US created food additive legislation stating that the FDA must approve all food
additives and ingredients that are not generally recognized as safe. The GRAS list contains
food additives that have been used historically and have shown no hazards during that
time. Easily recognized examples are sodium chloride, sucrose and acetic acid. Less easily
recognized are many of the common food preservatives such as sodium benzoate,
potassium sorbate, and calcium propionate.
9
The U.S. FDA maintains a list of over 3000 approved, generally recognized as safe, food
ingredients including food.
VCE Environmental Science - Unit 4: Pollution. The sources, sinks, human and environmental health effects of DDT and endocrine disruptors, including pthalates, are discussed in this presentation.
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This document provides an overview of unit 3 of the BOS 4201 Toxicology 1 course. The key learning outcomes for the unit are to explain how toxins are processed in biological systems, calculate statistics related to different toxin types, and assess environmental risk based on toxicity. Specific topics covered include differentiating pollution from contamination, describing how chemicals move through the environment, dose-response relationships, environmental pollutants like mercury, lead, and DDT, and their effects. Assessment of learning will involve lessons, readings on environmental pollutants and dose response, and differentiating pollution from contamination as well as how chemicals move through the environment.
Glyphosate has been the world's most widely used herbicide for decades. It was first synthesized in 1950 but not discovered to have herbicidal properties until 1970. Monsanto developed the first glyphosate-based herbicide, Roundup, in 1974. Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase in plants, interfering with the production of essential amino acids and causing plant death. Its use increased with the development of genetically modified glyphosate-resistant crops in the 1990s. While glyphosate has been very successful commercially, its widespread use has led to environmental and health concerns.
1. The document discusses trophic levels and provides examples of food chains and the trophic levels they contain, such as grass and insects.
2. It also discusses the role of decomposers in breaking down dead plants and animals and recycling nutrients, and why some substances are biodegradable while others are not.
3. Questions are asked about how biodegradable and non-biodegradable substances affect the environment, and the document provides answers about pollution and recycling.
Metoxuron is an organic herbicide belonging to the urea derivatives and chlorinated compounds class. It inhibits photosynthesis in weeds. Metoxuron was introduced in 1968 but banned in India in 1989 due to its long term toxicity to aquatic environments and ability to decrease grain yields. Prolonged exposure can also negatively impact human health by contaminating air, water, soil and the food chain.
Oxygen Interference in Methane Generation from Biodegradation of Solid Waste ...crimsonpublisherspps
The main solid wastes from tanneries are wet-blue shavings (chrome tanned leather) and sludge emitted mainly from waste-water treatment plants (WWTP). The main degradation process that occurs on solid media is anaerobic digestion. In this process the main products are methane (CH4), which has a high calorific value, and carbon dioxide (CO2); together these gases compose the emitted biogas. Methanogens, which are strict anaerobes, are responsible for the last step of anaerobic digestion and it is through their metabolism that methane is generated
https://crimsonpublishers.com/pps/fulltext/PPS.000505.php
For more open access journals in Crimson Publishers
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Tetracyclines are a class of antibiotics that were first discovered in the 1940s. They work by binding to the bacterial ribosome to inhibit protein synthesis. Resistance can develop via plasmids. They are absorbed from the GI tract and distributed throughout the body, including bones and breast milk. Most are excreted in urine but doxycycline is excreted in feces. Adverse effects include GI issues, liver toxicity, renal toxicity, tooth discoloration in children, and allergic reactions. They have a broad spectrum of activity against bacteria.
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This document summarizes a study that investigated the photocatalytic decolorization of methyl orange dye using TiO2/Fe3O4 and TiO2/Fe2O3 nanocomposites. Various ratios of the nanocomposites were synthesized using an ultrasonic-assisted deposition-precipitation method. Testing showed the 1 wt% Fe3O4/TiO2 nanocomposite achieved about 40% decolorization of methyl orange within 60 minutes of UV irradiation at room temperature, though it exhibited the least magnetism. Characterization of the nanocomposites involved scanning electron microscopy, X-ray diffraction, Brunauer–Emmet–Teller surface area analysis, and band gap determination.
Invisible Burden - Good Reasons to Get Rid of PBT Chemicals v2zq
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Bioaccumulation and biomagnification refer to the increasing concentration of pollutants like pesticides, mercury, and other chemicals as they move up the food chain. Bioaccumulation is when an organism absorbs more of a substance than it eliminates, resulting in increasing concentration over time. Biomagnification occurs when concentrations increase at each trophic level, so organisms at the top of food chains face greater exposure. Pollutants like DDT, PCBs, and mercury are especially prone to bioaccumulation and biomagnification due to their persistence and ability to concentrate in fatty tissues. This can negatively impact wildlife and pose risks to human health through consumption of contaminated fish and seafood.
Microorganisms play important roles in addressing global problems like climate change, pollution, and pandemics. They can remove carbon from the air, degrade air and water pollutants through biofiltration and bioremediation, and provide insights into preventing pandemics. Microbes also play critical roles in human health by aiding digestion, protecting the skin, and maintaining a balanced microbiome. While microbiology provides benefits, exploiting its principles without oversight could enable harm, such as inadequate water treatment leading to disease. Applications in agriculture, industry and medicine also offer economic opportunities through nitrogen fixation, photosynthesis, decomposition, and pharmaceutical production.
Chemical Trespass - A Toxic Legacy - Resources for Healthy Children www.scribd.com/doc/254613619 - For more information, Please see Organic Edible Schoolyards & Gardening with Children www.scribd.com/doc/254613963 - Gardening with Volcanic Rock Dust www.scribd.com/doc/254613846 - Double Food Production from your School Garden with Organic Tech www.scribd.com/doc/254613765 - Free School Gardening Art Posters www.scribd.com/doc/254613694 - Increase Food Production with Companion Planting in your School Garden www.scribd.com/doc/254609890 - Healthy Foods Dramatically Improves Student Academic Success www.scribd.com/doc/254613619 - City Chickens for your Organic School Garden www.scribd.com/doc/254613553 - Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica www.scribd.com/doc/254613494 - Simple Square Foot Gardening for Schools - Teacher Guide www.scribd.com/doc/254613410 - Free Organic Gardening Publications www.scribd.com/doc/254609890 ~
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
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How to Fix the Import Error in the Odoo 17Celine George
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it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
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Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
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Introduction to AI for Nonprofits with Tapp NetworkTechSoup
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Introduction to AI for Nonprofits with Tapp Network
Tributyltin - Report
1.
Pollutants'
Chemistry
Tributyltin
compounds
Joel
Emmanuel
Bortoni-‐González
June
11th,
2013
2. Introduction
Tributyltin
(TBT),
(C4H9)3Sn,
is
a
chemical
used
mostly
in
biocides
in
the
form
of
other
compounds
like
tributyltin
hydride,
(C4H9)3SnH,
and
tributyltin
oxide,
C24H54OSn2,
due
to
the
fact
that
TBT
by
itself
is
unstable
and
will
break
down
unless
combined.
It
is
part
of
the
aromatic
hydrocarbon
chemical
family.
These
types
of
hydrocarbons
have
alternating
double
and
single
bonds
between
carbon
atoms
forming
rings,
like
benzene
in
Figure
1.
The
term
aromatic
has
nothing
to
do
with
the
physical
property
of
aromaticity,
a
chemical
property
that
describes
the
way
in
which
a
conjugated
ring
of
unsaturated
bonds,
lone
pairs
or
empty
orbitals
exhibit
a
stabilization
stronger
than
would
be
expected
by
the
stabilization
of
conjugation
alone,
but
rather
to
the
fact
that
these
chemical
compounds
have
a
scent,
sweet
in
most
cases.
Figure
1.
Benzene
model
where
the
circle
denotes
the
alternating
double
and
single
bonds
between
carbon
atoms.
The
most
common
TBT
compound
is
the
tributyltin
oxide
(TBTO)
and
has
been
the
subject
of
most
TBT
tests.
This
compound
and
other
eight
TBT
compounds
are
referred
to
as
organotins.
Characteristics
TBT
compounds
are
liquids
often
colorless,
unlike
TBTO
that
tends
to
have
a
slightly
yellow
color,
and
have
an
odor
similar
to
gasoline.
TBTO
is
insoluble
in
water
due
to
the
fact
that
they
react,
but
is
soluble
in
hexane
and
most
organic
solvents
(ethanol,
ether,
halogenated
hydrocarbons,
etcetera)
and
is
flammable
but
does
not
form
explosive
mixtures
with
air.
Its
melting
point
is
located
around
53ºC
and
its
boiling
point
around
193ºC
and
it
has
a
density
of
1.103
g/ml
at
20ºC.
It
breaks
down
slowly
in
the
presence
of
oxygen,
light
or
heat.
Prominent
uses
TBTO
is
an
effective
biocidal
preservative
for
wood,
cotton
textiles,
paper
and
paints
and
stains
for
residential
homes.
Mainly,
it
is
added
as
an
antifouling
agent
in
numerous
formulations
of
marine
paints
and
boat
hulls,
docks,
fishnets
and
buoys
to
discourage
the
growth
of
marine
organisms
such
as
barnacles,
bacteria,
tubeworms,
mussels
and
algae.
3. Quality
regulations
Most
of
the
international
regulations
on
TBTO
derived
from
previous
cases
of
imposex
on
several
snail
species
in
France
and
Great
Britain.
Nowadays
regulations
tend
to
decrease
the
use
of
TBT
based
antifoulings.
In
1987
a
Europe-‐wide
ban
of
its
use
on
boats
of
under
25
meters
long
was
established.
In
the
United
Kingdom
the
use
of
TBT
based
paints
continues
on
larger
vessels
and
it
remains
at
present
the
most
effective
means
of
controlling
fouling.
In
November
1998
the
International
Maritime
Organization
made
the
decision
to
introduce
a
worldwide
ban
of
the
use
of
TBT
in
antifouling
paints
for
most
ships
from
January
2003,
a
ban
that
has
been
in
place
for
several
years
mainly
in
countries
with
a
lot
of
maritime
activity,
such
as
Japan.
Pressure
for
a
complete
ban
of
TBT
in
antifouling
paints
has
been
increasing
due
to
evidence
that
it
is
bio-‐accumulating
in
food
chains,
with
particularly
high
levels
being
found
in
marine
mammals.
Toxicity
Since
TBTO
is
used
mostly
on
products
that
will
be
in
touch
with
water
studies
of
the
effects
of
TBTO
products
on
living
organisms
have
been
primarily
performed
on
aquatic
life.
Effects
of
TBT
products
on
humans
are
not
clear,
but
several
incidents
of
human
exposure
to
the
biocide
have
been
reported:
underwear
treated
with
TBT
has
caused
severe
skin
irritation
to
its
wearer,
shipyard
workers
exposed
to
TBT
dust
and
vapors
developed
breathing
problems,
irritated
skin,
headaches,
colds,
flu,
fatigue
dizziness
and
stomach
ache.
TBT
exposure
can
also
irritate
the
eye
and
mucous
membranes
and
prolonged
exposure
may
cause
liver
and
kidney
damage.
M
&
T
Chemicals,
one
of
the
main
producers
of
TBTO,
claim
that
workers
exposed
to
this
substance
metabolize
it
within
3
days.
Single
exposure
of
TBTO
on
rats
demonstrated
a
transient
increase
in
adrenal
weight
shortly
after
exposure
and
a
transient
effect
on
thyroid
follicles;
these
effects
are
reversible.
Inhalation
studies
of
a
single
4
hours
exposure
of
rats
to
aerosols
of
TBTO
showed
irritation
and
enteritis.
Studies
where
10
male
and
10
female
rats
were
exposed
to
saturated
gases
of
TBTO
didn't
show
any
death
occurring
during
exposure
for
7
hours
or
in
the
following
14
days
observation
period.
Short
term
exposure
of
TBTO
on
10
male
and
10
female
rats
involving
repeated
inhalation
in
"nose
only"
chambers
during
4
hours
5
days
per
week
produced
sever
toxic
effects,
inflammatory
reactions
in
the
total
respiratory
tract
and
histological
changes
in
the
lymphatic
organs
were
observed;
5
males
and
6
females
died
during
this
study.
In
mammals,
high
levels
of
TBTO
can
affect
the
endocrine
glands,
upsetting
the
hormone
levels
in
the
pituitary,
gonad
and
thyroid
glands.
Large
doses
of
TBT
have
been
shown
to
damage
the
reproductive
and
central
nervous
systems,
bone
structure
and
the
gastrointestinal
track
of
mammals.
A
large
number
of
studies
have
been
conducted
showing
that
TBTO
causes
depression
of
immune
functions
dependant
on
the
thymus.
These
effects
occur
at
doses
lower
than
those
that
cause
other
toxicity;
the
critical
effect
for
TBTO
is
immunotoxicity.
4. Cancer
assessment
has
been
conducted
in
rats
and
mice
following
oral
exposure.
Increases
in
benign
pituitary
tumors,
in
pheochromocytomas
and
in
parathyroid
tumors
at
the
highest
dose
tested
were
shown.
It
is
unclear
if
TBTO
is
responsible
for
these
tumors
since
the
strain
of
rats
used
they
normally
occur
with
variable
incidence.
The
mice
didn't
show
any
sign
of
a
tumor
due
to
TBTO.
Eco
toxicity
Much
of
the
concern
of
the
use
of
tributyltin
stems
from
its
use
as
a
marine
antifoulent
in
paints.
This
compound
is
slowly
released
from
the
paint
on
the
hull
of
the
boat
into
the
adjoining
water
hindering
the
growth
and
attachment
of
a
variety
of
organisms
to
the
boat.
Consequently,
tributyltin
concentrations
in
harbors
and
bays
in
Great
Britain,
France
and
the
United
States
were
high
enough
to
significantly
affect
oyster
and
mussel
production.
Imposex,
the
development
of
male
characteristics
in
females,
has
been
initiated
by
TBT
exposure
in
several
snail
species.
In
laboratory
tests,
reproduction
was
inhibited
when
female
snails
exposed
to
50
ppt
of
TBT
developed
male
characteristics,
such
as
male
genitalia.
Imposex
was
also
noted
in
the
mud
snail
at
less
that
3
ppt
of
TBT.
TBT
is
extremely
toxic
to
crustaceans.
Lobster
larvae
show
a
nearly
complete
decrease
in
growth
at
just
1
ppb
of
TBT.
Molluscs,
used
as
indicators
of
TBT
pollution
because
of
their
high
sensitivity
to
those
chemicals,
react
adversely
to
very
low
levels
of
TBT
(0.06-‐2.3
ppb
of
TBT).
They
release
TBT
very
slowly
from
their
bodies
after
it
has
been
absorbed.
TBT
toxicity
in
the
field
may
be
substantially
underestimated
in
laboratory
studies.
TBT
binds
to
the
sides
of
containers
and
plankton,
which
contributes
to
this
underestimation
of
its
potential
toxicity.
Generally,
the
larvae
of
any
tested
species
are
more
sensitive
of
tributyltin
exposure
than
the
adults.
Some
fish
can
degrade
TBT
due
to
special
enzymes
that
these
fishes
contain.
In
the
Chinook
salmon,
once
absorbed
it
breaks
down
into
di-‐n-‐butyltin
(DBT).
Rainbow
trout
eggs
are
killed
between
10-‐12
days
of
TBT
exposure
at
5
ppb.
At
lower
levels
no
deaths
occurred,
but
blood
and
liver
metabolism
changes
were
noticed.
Growth
reduction
and
liver
changes
also
occurred
in
young
trout
exposed
to
lower
levels
of
tributyltin
chloride.
Also,
after
seven
days
of
low
level
TBTO,
the
corneal
membranes
of
the
rainbow
trout's
eyes
were
destroyed.
TBTO
has
been
shown
to
inhibit
cell
survival
of
marine
unicellular
algae
at
very
low
concentrations.
Pollution
in
Arcachon
Bay
and
beginning
of
the
ban
on
its
use
Until
the
mid
1970's,
Arcachon
Bay
had
been
an
important
area
for
oyster
culture,
with
production
of
10,000-‐15,000
tons
per
year,
covering
substantial
areas
of
the
tidal
mud
flats.
The
bay
was
also
popular
with
leisure
craft,
with
vessels
numbers
increasing
from
7,500
in
the
mid
1970's
to
15,000
at
the
start
of
the
1980's.
Estimated
inputs
of
TBT
to
the
bay
peaked
at
around
8
kg
per
day.
Imposex
was
first
observed
in
the
bay
in
1970,
affecting
the
predator
oyster
drill,
leading
rapidly
to
its
near
extirpation
from
the
bay.
TBT
was
identified
as
the
responsible
agent
only
in
the
early
1980's.
5. Had
the
adverse
effects
been
limited
to
the
loss
of
this
species,
considered
a
pest
within
the
shellfish
industry
for
its
damage
of
oyster
stocks,
little
if
any
action
may
have
followed.
However,
this
early
warning
was
followed
by
failure
of
the
oyster
stocks
themselves.
Despite
a
normal
spawning
event
in
the
summer
of
1976,
few
of
the
larvae
survived.
Larval
settlement
largely
failed
through
the
late
1970's
and
into
the
1980's,
resulting
in
massive
financial
losses
by
the
shellfish
industry.
By
1981,
oyster
production
had
fallen
to
only
3,000
tons.
In
addition
to
reproductive
failure,
adult
oysters
were
rendered
unsaleable
by
shell
deformation
leading,
in
sever
cases,
to
ball
shaped
specimens.
Such
observations
predated
analytical
techniques
sensitive
enough
to
describe
in
detail
environmental
distributions
of
TBT.
In
1986
the
first
survey
of
organotins
in
the
waters
of
Archon
Bay
was
provided,
while
sediments
data
were
not
available
until
the
1990's.
Nevertheless,
the
severity
of
impacts
on
the
ecology
of
Archon
Bay,
manifest
in
heavy
financial
losses,
was
sufficient
to
stimulate
relatively
swift
action
by
the
French
government.
Acting
on
the
best
information
available
linking
the
oyster
collapse
to
the
presence
of
TBT
paints
to
small
vessels
(less
than
25
meters
long)
in
1982,
beginning
the
ban
on
said
boats.
These
controls
undoubtedly
markedly
reduced
TBT
inputs
to
marinas
throughout
France.
In
the
case
of
Arcachon,
implementation
was
probably
aided
by
the
local
provenance
of
many
boat
owners
and
their
interest
in
preserving
a
local
industry.
Sources
Concise
International
Chemical
Assessment
Document
14:
Tributyltin
Oxide.
-‐
Dr.
Robert
Benson;
World
Health
Organization.
Tributyltin.
-‐
Extension
Toxicology
Network.
Retrieved
from:
http://pmep.cce.cornell.edu/profiles/extoxnet/pyrethrins-‐ziram/tributyltin-‐
ext.html
Tributyltin
(TBT)
antifoulants:
a
tale
of
ships,
snails
and
imposex.
-‐
David
Santillo,
Paul
Johnston
and
William
J.
Langston.
Tributyltin
pollution
on
a
global
scale.
An
overview
of
relevant
and
recent
search:
impacts
and
issues.
-‐
Dr.
Simon
Walmsley;
World
Wildlife
Fund.