Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampricide. The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are intended to serve as plant protection products, which in general, protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species.
Chlordecone, better known in the United States under the brand name Kepone, is an organochlorine compound and a colourless solid. It is an obsolete insecticide, now prohibited in the western world, but only after many thousands of tonnes had been produced and used. Chlordecone is a known persistent organic pollutant (POP) that was banned globally by the Stockholm Convention on Persistent Organic Pollutants in 2009.
Lindane, also known as gamma-hexachlorocyclohexane (γ-HCH), gammaxene, Gammallin and benzene hexachloride (BHC), is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and as a pharmaceutical treatment for lice and scabies.
Parathion, also called parathion-ethyl or diethyl parathion and locally known as "Folidol", is an organophosphate insecticide and acaricide. It was originally developed by IG Farben in the 1940s. It is highly toxic to non-target organisms, including humans, so its use has been banned or restricted in most countries. The basic structure is shared by parathion methyl.
Malathion is an organophosphate insecticide which acts as an acetylcholinesterase inhibitor. In the USSR, it was known as carbophos, in New Zealand and Australia as maldison and in South Africa as mercaptothion.
In organic chemistry, organophosphates are a class of organophosphorus compounds with the general structure O=P(OR)3, a central phosphate molecule with alkyl or aromatic substituents. They can be considered as esters of phosphoric acid.
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic chemicals that adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released.
Dieldrin is an organochlorine compound originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels-Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene.
Toxaphene was an insecticide used primarily for cotton in the southern United States during the late 1960s and the 1970s. Toxaphene is a mixture of over 670 different chemicals and is produced by reacting chlorine gas with camphene. It can be most commonly found as a yellow to amber waxy solid.
Heptachlor is an organochlorine compound that was used as an insecticide. Usually sold as a white or tan powder, heptachlor is one of the cyclodiene insecticides. In 1962, Rachel Carson's Silent Spring questioned the safety of heptachlor and other chlorinated insecticides. Due to its highly stable structure, heptachlor can persist in the environment for decades. In the United States, the Environmental Protection Agency has limited the sale of heptachlor products to the specific application of fire ant control in underground transformers. The amount that can be present in different foods is regulated.
Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after World War II. Other noteworthy examples of COCs include dieldrin and DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides became notorious as persistent organic pollutants.
Endosulfan is an off-patent organochlorine insecticide and acaricide that is being phased out globally. It became a highly controversial agrichemical due to its acute toxicity, potential for bioaccumulation, and role as an endocrine disruptor. Because of its threats to human health and the environment, a global ban on the manufacture and use of endosulfan was negotiated under the Stockholm Convention in April 2011. The ban took effect in mid-2012, with certain uses exempted for five additional years. More than 80 countries, including the European Union, Australia, New Zealand, several West African nations, the United States, Brazil, and Canada had already banned it or announced phase-outs by the time the Stockholm Convention ban was agreed upon. It is still used extensively in India and China despite laws against its use. It is also used in a few other countries. It is produced by the Israeli firm Makhteshim Agan and several manufacturers in India and China. On 13.05.2011, the India Supreme Court ordered a ban on the production and sale of endosulfan in India, pending further notice.
Endrin is an organochlorine compound with the chemical formula C12H8Cl6O that was first produced in 1950 by Shell and Velsicol Chemical Corporation. It was primarily used as an insecticide, as well as a rodenticide and piscicide. It is a colourless, odorless solid, although commercial samples are often off-white. Endrin was manufactured as an emulsifiable solution known commercially as Endrex. The compound became infamous as a persistent organic pollutant and for this reason it is banned in many countries.
Mirex is an organochloride that was commercialized as an insecticide and later banned because of its impact on the environment. This white crystalline odorless solid is a derivative of cyclopentadiene. It was popularized to control fire ants but by virtue of its chemical robustness and lipophilicity it was recognized as a bioaccumulative pollutant. The spread of the red imported fire ant was encouraged by the use of mirex, which also kills native ants that are highly competitive with the fire ants. The United States Environmental Protection Agency prohibited its use in 1976. It is prohibited by the Stockholm Convention on Persistent Organic Pollutants.
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons, solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer modelling, and GIS in Environmental Contamination, as well as an appreciation of the history of industrial chemistry.
Methoxychlor is a synthetic organochloride insecticide, now obsolete. Tradenames for methoxychlor include Chemform, Maralate, Methoxo, Methoxcide, Metox, and Moxie.
Phosmet is a phthalimide-derived, non-systemic, organophosphate insecticide used on plants and animals. It is mainly used on apple trees for control of codling moth, though it is also used on a wide range of fruit crops, ornamentals, and vines for the control of aphids, suckers, mites, and fruit flies.
Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical, biological and physical agents on living organisms. Ecotoxicology is a subdiscipline of environmental toxicology concerned with studying the harmful effects of toxicants at the population and ecosystem levels.
Hexachlorocyclopentadiene (HCCPD), also known as C-56, Graphlox, and HRS 1655, is an organochlorine compound with the formula C5Cl6. It is a precursor to pesticides, flame retardants, and dyes. It is a colourless liquid, although commercial samples appear lemon-yellow liquid sometimes with a bluish vapour. Many of its derivatives proved to be highly controversial, as studies showed them to be persistent organic pollutants. An estimated 270,000 tons were produced until 1976, and smaller amounts continue to be produced today. Two prominent manufacturers are Velsicol Chemical Corporation in the US and by Jiangsu Anpon Electrochemicals Co. in China.
Health effects of pesticides may be acute or delayed in those who are exposed. Acute effects can include pesticide poisoning, which may be a medical emergency. Strong evidence exists for other, long-term negative health outcomes from pesticide exposure including birth defects, fetal death, neurodevelopmental disorder, cancer, and neurologic illness including Parkinson's disease. Toxicity of pesticides depend on the type of chemical, route of exposure, dosage, and timing of exposure.
