Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: What is an organophosphate?
Organophosphate is the general name for esters of phosphoric acid and is one of the organophosphorus compounds. They can be found as part of insecticides, herbicides, and nerve gases, amongst others. Some less-toxic organophosphates can be used as solvents, plasticizers, and EP additives. The use of organophosphates accounts for approximately 38% of all pesticide use globally.
Organophosphates inhibit AChE, causing OP poisoning by phosphorylating the serine hydroxyl residue on AChE, which inactivates AChE. AChE is critical for nerve function, so the irreversible blockage of this enzyme, which causes acetylcholine accumulation, results in muscle overstimulation. This causes disturbances across the cholinergic synapses and can only be reactivated very slowly, if at all. Paraoxonase (PON1) is a key enzyme involved in OP pesticides and has been found to be critical in determining an organism's sensitivity to OP exposure.
An organic diet is an effective way to reduce exposure to the organophosphorus pesticides commonly used in agricultural production. Organophosphate metabolite levels rapidly drop, and for some metabolites, become undetectable in children's urine when an organic diet is consumed. This is speculative based on a short study of 23 children, in which only a few organophosphate compounds were potentially reduced, no effect was shown for the majority of them that were found in the samples.
Pesticide use is widespread in Latin America, as around US $3 billion are spend each year in the region. It has been recorded that pesticide poisonings have been increasing each year for the past two decades. It was estimated that 50–80% of the cases are unreported. It is indicated by studies that organophosphate and carbamate insecticides are the most frequent source of pesticide poisoning.
"Most estimates concerning the extent of acute pesticide poisoning have been based on data from hospital admissions which would include only the more serious cases. The latest estimate by a WHO task group indicates that there may be 1 million serious unintentional poisonings each year and in addition 2 million people hospitalized for suicide attempts with pesticides. This necessarily reflects only a fraction of the real problem. On the basis of a survey of self-reported minor poisoning carried out in the Asian region, it is estimated that there could be as many as 25 million agricultural workers in the developing world suffering an episode of poisoning each year." In Canada in 2007 more than 6000 cases of acute pesticide poisoning occurred.
Self-poisoning with agricultural pesticides represents a major hidden public health problem accounting for approximately one-third of all suicides worldwide. It is one of the most common forms of self-injury in the Global South. The World Health Organization estimates that 300,000 people die from self-harm each year in the Asia-Pacific region alone. Most cases of intentional pesticide poisoning appear to be impulsive acts undertaken during stressful events, and the availability of pesticides strongly influences the incidence of self poisoning. Pesticides are the agents most frequently used by farmers and students in India to commit suicide.
The fermentation processes cause the contents of a septic tank to be anaerobic with a low redox potential, which keeps phosphates in a soluble and, thus, mobilized form. Phosphates discharged from a septic tank into the environment can trigger prolific plant growth including algal blooms, which can also include blooms of potentially toxic cyanobacteria.
Acetaminophen exerts its toxicity through the production of a toxic metabolite that can cause liver damage at doses as low as four grams. Larger doses can precipitate acute liver failure, acute kidney injury, or gastrointestinal bleeding; death has been known to occur with ingestion of ten to fifteen grams. The specific antidote to acetaminophen overdose is "N"-acetylcysteine.
Some common household chemicals are particularly dangerous to dogs:Poisoning with pain medications is common. Aspirin, paracetamol (acetaminophen, Tylenol), ibuprofen (Advil), and naproxen (Aleve) can all cause severe clinical signs in dogs, including vomiting blood, diarrhea, and abdominal pain. Specifically, aspirin can cause metabolic acidosis and bleeding disorders, acetaminophen can cause liver disease, ibuprofen can cause kidney disease, and naproxen can cause ulcers in the stomach, which can perforate. Treatment depends on the clinical signs.
Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered. It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.
Xenoestrogens are a type of xenohormone that imitates estrogen. They can be either synthetic or natural chemical compounds. Synthetic xenoestrogens include some widely used industrial compounds, such as PCBs, BPA, and phthalates, which have estrogenic effects on a living organism even though they differ chemically from the estrogenic substances produced internally by the endocrine system of any organism. Natural xenoestrogens include phytoestrogens which are plant-derived xenoestrogens. Because the primary route of exposure to these compounds is by consumption of phytoestrogenic plants, they are sometimes called "dietary estrogens". Mycoestrogens, estrogenic substances from fungi, are another type of xenoestrogen that are also considered mycotoxins.
Acute overdoses of paracetamol can cause potentially fatal liver damage. In 2011, the U.S. Food and Drug Administration launched a public-education program to help consumers avoid overdose, warning: "Acetaminophen can cause serious liver damage if more than directed is used." In a 2011 Safety Warning, the FDA immediately required manufacturers to update labels of all prescription combination acetaminophen products to warn of the potential risk for severe liver injury and required that such combinations contain no more than 325 mg of acetaminophen. Overdoses are frequently related to high-dose recreational use of prescription opioids, as these opioids are most often combined with acetaminophen. The overdose risk may be heightened by frequent consumption of alcohol.
The organ pipe mud dauber ("Trypoxylon politum") is a predatory wasp in the family Crabronidae. They are fairly large wasps, ranging from 3.9–5.1 mm, and have been recorded to fly from May to September. Female and male are similar in colour, a shiny black with pale yellow to white hind hindtarsomere. The organ pipe mud dauber feeds mainly on three genera of spider: Neoscona, Araneus, and Eustala. Melittobia, a parasitoid wasp, is a common ectoparasite of "T. politum" prepupae. Other sources of parasitism include the Bombyliid fly Anthrax, Chrysidid wasps, and various species of scavenger flies (Miltogramminae). The tufted titmouse ("Parus bicolor") is a known predator of "T. politum", and may feed on them more commonly than previously thought as the holes made by the titmouse are similar in shape and size to those made by T. politum leaving the nest after pupation.
Many over-the-counter and prescription-only medications contain paracetamol. Because of its wide availability paired with comparably high toxicity, (compared to ibuprofen and aspirin) there is a much higher potential for overdose. Paracetamol toxicity is one of the most common causes of poisoning worldwide. In the United States, the United Kingdom, Australia, and New Zealand, paracetamol is the most common cause of drug overdoses. Additionally, in both the United States and the United Kingdom it is the most common cause of acute liver failure.
In England and Wales an estimated 41,200 cases of paracetamol poisoning occurred in 1989 to 1990, with a mortality of 0.40%. It is estimated that 150 to 200 deaths and 15 to 20 liver transplants occur as a result of poisoning each year in England and Wales. Paracetamol overdose results in more calls to poison control centers in the US than overdose of any other pharmacological substance, accounting for more than 100,000 calls, as well as 56,000 emergency room visits, 2,600 hospitalizations, and 458 deaths due to acute liver failure per year. A study of cases of acute liver failure between November 2000 and October 2004 by the Centers for Disease Control and Prevention in the USA found that paracetamol was the cause of 41% of all cases in adults, and 25% of cases in children.
An active metabolite results when a drug is metabolized by the body into a modified form which continues to produce effects in the body. Usually these effects are similar to those of the parent drug but weaker, although they can still be significant (see e.g. 11-hydroxy-THC, morphine-6-glucuronide). Certain drugs such as codeine and tramadol have metabolites (morphine and "O"-desmethyltramadol respectively) that are stronger than the parent drug and in these cases the metabolite may be responsible for much of the therapeutic action of the parent drug. Sometimes, however, metabolites may produce toxic effects and patients must be monitored carefully to ensure they do not build up in the body. This is an issue with some well-known drugs such as pethidine (meperidine) and dextropropoxyphene.
The second phase occurs between 24 h and 72 h following overdose and consists of signs of increasing liver damage. In general, damage occurs in liver cells as they metabolize the paracetamol. The individual may experience right upper quadrant abdominal pain. The increasing liver damage also changes biochemical markers of liver function; International normalized ratio (INR) and the liver transaminases ALT and AST rise to abnormal levels. Acute kidney failure may also occur during this phase, typically caused by either hepatorenal syndrome or multiple organ dysfunction syndrome. In some cases, acute kidney failure may be the primary clinical manifestation of toxicity. In these cases, it has been suggested that the toxic metabolite is produced more in the kidneys than in the liver.
Polycyclic aromatic hydrocarbons (PAHs, also polyaromatic hydrocarbons or polynuclear aromatic hydrocarbons) are hydrocarbons—organic compounds containing only carbon and hydrogen—that are composed of multiple aromatic rings (organic rings in which the electrons are delocalized). The simplest such chemicals are naphthalene, having two aromatic rings, and the three-ring compounds anthracene and phenanthrene.
The toxin has been implicated in cases of respiratory irritation, inflammation of the eye and severe contact dermatitis in fishermen. Antillatoxin is a very potent neurotoxin, although exact toxicity differs between species. The lethal concentration LC is about 0.1 µM for goldfish, making it the most potent toxin known for goldfish after brevetoxin. It can be cytotoxic to single cerebellar granule cells at concentrations as low as 20 nM in rats but more typically at 50 nM.
The botulinum toxin can cause a severe flaccid paralytic disease in humans and other animals and is the most potent toxin known to mankind, natural or synthetic, with a lethal dose of 1.3–2.1 ng/kg in humans.
Polycyclic aromatic hydrocarbons (PAHs) are aromatic hydrocarbons that consist of fused aromatic rings and do not contain heteroatoms or carry substituents. Naphthalene is the simplest example of a PAH. PAHs occur in oil, coal, and tar deposits, and are produced as byproducts of fuel burning (whether fossil fuel or biomass). As pollutants, they are of concern because some compounds have been identified as carcinogenic, mutagenic, and teratogenic. PAHs are also found in cooked foods. Studies have shown that high levels of PAHs are found, for example, in meat cooked at high temperatures such as grilling or barbecuing, and in smoked fish.
According to the EPA, organophosphate use in 2004 accounts for 40% of all insecticide products used in the United States. Out of concerns for potential hazards of organophosphate exposure to child development, the EPA began phasing out forms of organophosphates used indoors in 2001. While it is used in forestry, urban, and public health spraying (mosquito abatement programs, etc.) as well, the general population has been observed to have low exposure . Thus, the primary affected population that faces exposure to organophosphates are farmworkers, especially those in countries that have fewer restrictions on its usage, such as in India.
Many "organophosphates" are potent nerve agents, functioning by inhibiting the action of acetylcholinesterase (AChE) in nerve cells. They are one of the most common causes of poisoning worldwide, and are frequently intentionally used in suicides in agricultural areas. Organophosphosphate pesticides can be absorbed by all routes, including inhalation, ingestion, and dermal absorption. Their inhibitory effects on the acetylcholinesterase enzyme lead to a pathological excess of acetylcholine in the body. Their toxicity is not limited to the acute phase, however, and chronic effects have long been noted. Neurotransmitters such as acetylcholine (which is affected by organophosphate pesticides) are profoundly important in the brain's development, and many organophosphates have neurotoxic effects on developing organisms, even from low levels of exposure. Other organophosphates are not toxic, yet their main metabolites, such as their oxons, are. Treatment includes both a pralidoxime binder and an anticholinergic such as atropine.
Under a 1988 amendment to the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the U.S. Environmental Protection Agency (EPA) regulates organophosphate pesticides Its focus was initially on registering pesticides for use on food crops. No pesticide can be sold in the United States before the EPA has reviewed the manufacture's application for registration and determined that the use of the product will not present an unreasonable risk to the public or the environment. In 1996, with the passage of the Food Quality Protection Act, Congress required the EPA to reassess all existing pesticide tolerances with specific consideration for children. This resulted in a 10-year review process of the health and environmental effects of all pesticides, beginning with the organophosphates. As part of that process, in 1999 the EPA announced a ban the use of organophosphate pesticide methyl parathion and significant restrictions on the use of another OP, azinphos methyl, in what they called "kid's food". The review process was concluded in 2006 and eliminated or modified thousands of other uses of pesticides. Other legislative action has been taken to protect children from the risks of organophosphates.
Carbophenothion is a highly toxic organophosphate insecticide and acaricide. Organophosphates are acetylcholinesterase inhibitors and disrupt the signal transduction at the cholinergic synapse. It is classified as Restricted Use Pesticide (RUP) by the Environmental Protection Agency (EPA). Carbophenothion is used in different brands like Trithion. This pesticide contains 80% carbophenothion as its only active ingredient. Because of the widespread use of those organophosphates in the nineties in the US, it was the most common cause of agricultural poisonings.