Pesticide
The word pesticide derives from the Latin pestis meaning plague and caedere meaning kill. This etymology reveals the original intent of these substances as tools to destroy organisms deemed harmful to human interests. The Food and Agriculture Organization defines a pesticide as any substance or mixture intended for preventing, destroying, or controlling pests including vectors of disease. These agents target insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes, and microbes that cause nuisance or spread disease. Modern usage includes herbicides which account for approximately 50% of all global pesticide use today. Inorganic compounds like copper and arsenic derivatives were used in ancient times while synthetic organic compounds emerged later. Biopesticides represent another category derived from natural materials such as bacteria fungi viruses and minerals. The classification system distinguishes between systemic pesticides that move inside plants and contact pesticides that remain on surfaces.
From ancient times until the 1950s the pesticides used were inorganic compounds and plant extracts. The less toxic versions of these early formulations are still in use in organic farming today. In the 1940s the insecticide DDT and the herbicide 2,4-D were introduced into widespread agricultural practice. These synthetic organic compounds were very profitable and led to rapid growth of the pesticide industry during the following decades. By the 1970s it became evident that DDT had accumulated in the food chain becoming a global pollutant. Silent Spring summarized this environmental crisis before DDT was banned in several countries. Persistent pesticides including DDT have been banned worldwide with exceptions for spraying interior walls to combat malaria vectors. Resistance to pesticides first appeared in the 1920s with inorganic compounds and has become an expected phenomenon requiring management strategies. Integrated pest management was introduced in the 1950s to reduce unnecessary chemical application through careful analysis of crop damage thresholds.
The cost of developing a new pesticide in 2024 was estimated at 301 million US dollars. This figure reflects the difficulty of finding new active ingredients as more than 100 were introduced in the 2000s while fewer than 40 emerged in the 2010s. The registration process can take several years to complete involving 70 types of field tests costing between 50 and 70 million dollars per product. Biopesticides are cheaper to develop since authorities require less toxicological and environmental study. In 2018 world pesticide sales reached 65 billion dollars with 88% used for agriculture. Generic products accounted for 85% of those sales figures. One study found that every dollar spent on pesticides results in up to four dollars worth of crops saved from loss. Despite higher costs, farmers benefit from increased yields and the ability to grow diverse crops year-round. Consumers also gain access to vast quantities of produce available throughout the seasons due to these economic efficiencies.
Most health concerns related to pesticides stem from direct use whether in occupational or non-occupational settings. A 2007 systematic review found positive associations between pesticide exposure and conditions like non-Hodgkin lymphoma and leukemia. Studies show farm workers in Ethiopia Kenya and Zimbabwe have decreased concentrations of plasma acetylcholinesterase an enzyme responsible for breaking down acetylcholine. Excess acetylcholine leads to symptoms including muscle cramps tremors confusion dizziness and nausea. The World Health Organization estimates that 3 million agricultural workers in developing countries experience severe poisoning each year resulting in 18,000 deaths. Ninety-nine percent of pesticide-related deaths occur in developing nations accounting for only 25% of global usage. Self-poisoning using pesticides represents the method of choice in one third of suicides worldwide. Children may be exposed through take-home residues collected on parent clothing or equipment brought into homes. Prenatal exposure during pregnancy presents additional risks for neurocognitive development and impaired growth in newborns.
Over 98% of sprayed insecticides and 95% of herbicides reach destinations other than their target species. Pesticide drift occurs when particles suspended in air are carried by wind to contaminate neighboring areas. These substances contribute to water pollution soil contamination and flower pollen nectar damage. Invertebrate biodiversity in streams has declined while pollinator populations face threats from widespread application. Bird habitats have been destroyed and endangered species remain at risk due to chemical exposure. The Stockholm Convention banned persistent organic pollutants like DDT which were stable lipophilic compounds able to bioaccumulate in bodies and food chains. Residues can still be detected in humans at levels five to ten times lower than found in the 1970s despite bans implemented decades ago. Pests develop resistance necessitating either new chemicals or greater doses that worsen ambient pollution problems. Bioindicators such as bee pollinators help monitor environmental contamination levels across different regions globally.
In many countries pesticides must be approved for sale and use by government agencies before distribution. Worldwide 85% of nations have pesticide legislation for proper storage while 51% include provisions ensuring disposal of obsolete products. Delegates to a United Nations Food and Agriculture Organization conference adopted an International Code of Conduct on Distribution and Use of Pesticides in 1985 creating voluntary standards. The Environmental Protection Agency regulates pesticides under FIFRA and FQPA requiring over 100 tests for those used on food. All registered pesticides are reviewed every 15 years to ensure compliance with current scientific and regulatory standards. Restricted use pesticides require certified applicators who pass exams before purchasing or supervising application. Records of sales and usage must be maintained and audited by enforcement agencies. In 2023 the European Parliament approved decisions aiming to reduce pesticide use by 50% by 2030 with hazardous types reduced by 65%. Maximum residue limits are carefully set to prevent health impacts from consumption of treated food sources.
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Common questions
What is the etymology of the word pesticide?
The word pesticide derives from the Latin pestis meaning plague and caedere meaning kill. This etymology reveals the original intent of these substances as tools to destroy organisms deemed harmful to human interests.
When was DDT banned worldwide for general use?
Persistent pesticides including DDT have been banned worldwide with exceptions for spraying interior walls to combat malaria vectors. Silent Spring summarized this environmental crisis before DDT was banned in several countries by the 1970s when it became evident that DDT had accumulated in the food chain becoming a global pollutant.
How much does it cost to develop a new pesticide in 2024?
The cost of developing a new pesticide in 2024 was estimated at 301 million US dollars. This figure reflects the difficulty of finding new active ingredients as more than 100 were introduced in the 2000s while fewer than 40 emerged in the 2010s.
Where do most pesticide-related deaths occur globally?
Ninety-nine percent of pesticide-related deaths occur in developing nations accounting for only 25% of global usage. The World Health Organization estimates that 3 million agricultural workers in developing countries experience severe poisoning each year resulting in 18,000 deaths.
What percentage of sprayed insecticides reach their target species?
Over 98% of sprayed insecticides and 95% of herbicides reach destinations other than their target species. Pesticide drift occurs when particles suspended in air are carried by wind to contaminate neighboring areas.