Tuesday, February 21, 2012

what are pesticides ?

what are pesticides ?
Pesticide :
A pesticide is any substance to spread culture to fight against organisms harmful .  It is a term generic bringing together the insecticides , and fungicides , and herbicides , the fungicidal .  They attack respectively to insect pests , to mushrooms , to " weed "and to parasites.

 The term pesticide is often wrongly confused with substances " plant "or" plant protection ", but it also includes animal health products, products of wood treatments, and many household products: shampoo lice, moth balls, anti powders Ant, antimouches bombs, flea collars, insect repellent diffusers ...

 In a broader sense, such as the European regulations  , this may be the growth regulators, or substances that address public health problems (such as cockroaches in homes), public health (parasitic insects lice , fleas or vectors of diseases such as malaria and pathogenic bacteria destroyed by water chlorination), animal health, or for non-agricultural surfaces (roads, airports, railways, power grids ...).

Etymology :
The word pesticide was created in English, on the model of many words ending in the suffix-cide (Latin-cida, from the Latin verb caedo, Caedes, caedere, caedi, caedum, "kill"), and on the basis of English word pest (animal, insect or weed), which comes (as the French plague) which designated the Latin pestis such a pest.

History :
Chemical control has existed for millennia: the use of sulfur goes back to ancient Greece (1000 BC) and the arsenic is recommended by Pliny , Roman naturalist, as an insecticide.  Of plants known for their toxic properties were used as pesticides (eg aconite , in the Middle Ages, against rodents).  Treaties on these plants have been written (Ex: Treaty of poisons Maimonides in 1135 ).  Products arsenic -based or lead ( lead arsenate ) were used in the sixteenth century in China and Europe.
 The insecticidal properties of tobacco were known from 1690 .  In India, gardeners used the roots of Derris and Lonchocarpus ( rotenone ) as an insecticide.  Their use has spread to Europe around 1900 .

 Mineral chemistry has developed in the nineteenth century, providing many pesticides based mineral salts of copper .  The fungicides containing copper sulphate spreads, particularly the famous Bordeaux mixture (mixture of copper sulphate and lime ) to fight against fungal invasion of the vine and the potato, not without a legacy of pollution on soil (copper nondegradable).  Salts of mercury are used in the early twentieth century for seed treatment.


The era of synthetic pesticides began in earnest in the 1930s, taking advantage of the development of synthetic organic chemistry and research on chemical weapons during the First World War .
 In 1874, Zeidler synthesized DDT (dichlorodiphenyltrichloroethane), which established in 1939 Muller insecticidal properties.  DDT has been marketed since 1943 and opens the door to the family of organochlorines .  DDT dominated the insecticide market until early 1970.

 In 1944, the herbicide 2,4-D, copied to a growth hormone of plants and still heavily used today, is synthesized.

 The World War II generated through the research undertaken for the development of poison gas, the family of organophosphate which since 1945 has seen considerable development still appropriate today for some of these products, such as malathion .

 In 1950-1955 is developed in the United States the herbicide family of substituted ureas ( linuron , diuron ), followed shortly after by herbicides group quaternary ammonium and triazines .

 The benzimidazole fungicides and pyrimides date from 1966, followed by fungicides imidazole and triazole fungicides called IBS (inhibitors of the synthesis of sterols ) which currently represent the largest market for fungicides .

 In the years 1970-1980 is a new class of insecticides , the pyrethroids that dominate the market share for insecticides.

 Previously, the search for active ingredients was random by submitting numerous products to biological tests.  When a product was chosen for these qualities biocides, sought to improve efficiency through the synthesis of analogues.  This procedure has allowed the development of synthesis techniques that are appropriate today.

 Now the emphasis is on understanding the mechanisms of action and the search for new targets.  Knowing the target, then we can establish structure-activity relationships for the achievement of obtaining active ingredients.  This is possible through the development of basic research in the fields of biology and chemistry and the new tools provided by quantum chemistry, mathematics and computer science that allow modeling of the future molecules .

 Currently, there is a market consolidation in families with the most recent discoveries in search of new properties.  At the same time, new physiological targets of the animal or plant are explored to develop products to original operating methods, products derived from biotechnology or chemical mediators.

Consumption :
Since 1 July 2010 FAO opened free to all (upon registration) its database FAOSTAT Pesticides in the tool (the largest global database on food, agriculture and hunger)

 A distinction is often agricultural use (eg 54% of sales in 2000 in Wallonia  , which consumes less than Flanders) and non-farm (eg approximately 33% of sales in 2000 in Wallonia  ) which include products used by gardeners, local authorities and managers of roads, railways, canals, business parks, airports, etc..  In the case of Wallonia, in 2000, 13% of sales in 2000 remained "unidentified with sufficient accuracy"  , and for some products, field surveys show that "the total amounts applied exceed the quantities sold (about 20% of quantities) and vice versa for other products  . "
 The tonnages tend to decrease, but at least largely in part because the products are much more active at lower doses.

Agriculture :
The quantities of pesticides used around the world have increased steadily for 60 years.  They appear to be declining in some countries in Europe, but at the same weight or dose, the active ingredients of today, are generally much more effective than those of previous decades, France has, in 2008, the fourth global consumer of pesticides  .  Far behind the United States , and after Japan and Brazil.
 Marketed molecules evolve to circumvent resistance (insects, fungi or plants), to replace banned because of their toxicity, or when the molecules are a priori interesting to replace others.

 The most widely used pesticides (in quantity) are herbicides.
 The active molecule as the best selling and most widely used weedkiller in the world is glyphosate .

 Globally, it is the rice-producing countries (Japan, Korea, ..) with the highest consumption of pesticides per hectare, four times the European average, which itself is higher than that of the United States.  Among European countries, France is ranked 4 th behind including the Netherlands and other countries in which production systems are primarily oriented horticulture and vegetable production  .  .

 The Grenelle Environment (2007) asked 50% reduction in the quantities of active material used, if possible before 2018.  A 30% reduction of pesticides would be possible in France, with significant changes in practices, but without disrupting production systems, according to a study " Ecophyto R & D ", commissioned by the ministers responsible for agriculture and the environment a team coordinated by INRA, following the Grenelle Environment  .  Other studies (Project Endure) estimate  with innovative technologies could reduce, for maize, 100% of the seed treatment products, up to 85% the spraying of insecticides and 90% those herbicides.

 Nevertheless, according to UIPP (Union of Industrial and Plant Protection  ), with 63,700 t of active ingredient sold in the year, the market fell 19% (by ​​volume in 2009)  .  Manufacturers cite higher prices, lower pest pressure, good weather conditions (including a cold spring) or falling incomes of farmers operating large crops.

 The Grenelle II provides that "the Government shall submit annually to Parliament and make public a report on the monitoring of agricultural and nonagricultural uses of plant protection products in France, as well as advances in agricultural research in this area"  .  This report will point to the annual distribution of alternatives to pesticides among farmers, applied research and training, but also on "the health of farmers and agricultural workers, and the results of epidemiological surveillance program as defined in Article 31 of Law No. 2009-967 of 3 August 2009 relating to the implementation of the Grenelle Environment Forum. This report assesses the impact on health, environmental, social and economic uses of these. It clarifies the scope of each new standard for plant protection products adopted in France under EU rules and practices in the European Union. "  Elements of economic impact assessment of a reduction in France, seen by INRA, was published in May 2011  .

Weapon of War :
The Agent Orange (produced by Monsanto) is the nickname given to the most used herbicides used by the U.S. Army during the Vietnam War, particularly between 1961 and 1971.  Initially, the pathogenic effects on humans were unknown.  This product was used exclusively in order to clear the approaches of military installations and to ensure deforestation to prevent enemy combatants to hide.