Pesticides and Safety: the Pros and Cons of Pesticides.by Aaditya Singh | 04-10-2017 07:35 |
|---|
|
Before I start my report I want to introduce fellow members to a book. Published in 1962, 'Silent Spring', an environmental science book by Rachel Carson, documented the detrimental effects of indiscriminate use of pesticides. The book met with fierce opposition from chemical companies, but it managed to spur a reversal in the American pesticide policy. It led to a nationwide ban on DDT (Dichloro-Diphenyl-Trichloroethane) for agricultural uses in the USA and inspired a movement that led to the creation of the U.S. Environmental Protection Agency. In 2006, Silent Spring was named one of the 25 greatest science books of all time by the editors of Discover Magazine. And today in 2017, we are still trying to highlight the pros and cons of the use of Pesticides. I wonder why? Sustainability rests on three pillars- People, Planet and Profits. But some People appear to have forgotten the Planet for the sake of Profits. With respect to Pesticides, I would say that their use started as the intended solution to a problem but they have ended up turning into a problem themselves due to uncontrolled and injudicious use. What are Pesticides? Pesticides are chemical compounds that are used to kill pests and also unwanted plants (weeds). They are used in public health to kill vectors of disease, such as mosquitoes, and in agriculture, to eliminate or control a variety of agricultural pests that can damage crops and livestock and reduce farm productivity. The most commonly applied pesticides are insecticides (to kill insects), herbicides (to kill weeds), rodenticides (to kill rodents), and fungicides (to control fungi, mold, and mildew). A Brief History Man has been using pesticides for years. Ancient Sumerians used Elemental sulfur to protect crops from insects. Medieval farmers and scientists experimented with chemicals ranging from arsenic to lead on common crops. 19th Century research brought forward natural pesticides made with roots of tropical vegetables and chrysanthemums. DDT discovered in 1939, was very effective and became the world?s most widely used insecticide till 20 years later, 86 countries banned its use, due to serious concerns about human safety and biological effects of DDT. Later in the 1950s, consolidation of farms and subsequent rise in industrial growing practices such as mono-cropping saw widespread use of pesticides, many of which had been developed through the military funding of science after the Second World War. Toxicity There are more than 1000 pesticides in use, each with different properties and toxicological effects. The toxicity of a pesticide depends on its function and other factors. Insecticides are generally more toxic to humans than herbicides. Furthermore, toxic effect also depends on the dose and can vary depending on how much of the chemical a person is exposed to. It can also differ based on the mode of exposure occurs (such as swallowing, inhaling, or direct contact with the skin). Besides direct toxicity, Pesticides build up to dangerous levels, being magnified throughout the food chain, and have been detected in products ranging from meat, poultry and fish, to vegetable oil, nuts, fruit and vegetables. Recent incidents in parts of Europe, of eggs contaminated with the insecticide Fipronil, and similar issues in South Korea, caused trouble in the egg industry, have raised concerns over indiscriminate use of Pesticides. Harmful Effects Pesticides, particularly derivatives of chlorinated pesticides, are harmful because they can bio-accumulate and build up to dangerous levels in the body and environment Effect on Public Health Pesticides are potentially toxic to humans and can have both acute and chronic health effects, depending on the quantity and ways in which a person is exposed, with possible connection between pesticides and neurologic and endocrine (hormone) system disorders, Parkinson?s, Alzheimer?s, autism, cancer, poisonings, infertility, birth defects and more. Repeated contact with even small doses of pesticides can cause build up in the body, possibly causing immune and nervous system disorders years after exposure. Effect on Livestock When grain is grown with pesticides is fed to livestock, pesticide residues can accumulate in the animals' fatty tissue and milk. Pesticides, such as arsenic compounds, are also included in livestock feed to control intestinal parasites and other pests. Effect on Environment Furthermore the negative impacts on the environment are immense. Pesticides greatly impact biodiversity. They also poison pollen and nectar in flowers, leading to dwindling population of bees, the pollinators so necessary for our crop production. It has also been noticed that due to overuse, insects are becoming resistant to pesticides, causing farmers to use more spray than necessary. It is estimated that only 80% of ground applied pesticides reach their targeted areas the rest ends up in air, water, or ground that it wasn?t intended for. Moreover, some of the older, cheaper pesticides such as DDT and Lindane can remain for years in soil and water. These chemicals have been banned from agricultural use in developed countries who signed the 2001 Stockholm Convention aimed at eliminating or restricting the production and use of persistent organic pollutants. However, they are still used in many developing countries. Who is most at risk? People who are directly exposed to pesticides, including agricultural workers who apply pesticides, and other people in the immediate area during and right after pesticides are applied/spread. The general population is exposed to significantly lower levels of pesticide residues through food and water, though these too can be dangerous. Children are especially susceptible to the harmful effects of pesticide residues due to their lower body mass, rapid development, and higher rates of consumption of affected products. Why are Pesticides still in use? Pesticides play a significant role in food production. They protect or increase yields and also increase the number of times per year a crop can be grown on the same land. This is of great importance in underdeveloped or developing countries that face food shortages, in order to accommodate the increased food requirement of their population growth. Pesticides will therefore continue to play a role in agriculture by preventing large crop losses. Macro Level Mitigation As is obvious, production, distribution, and use of pesticides require strict regulation and control. Regular monitoring of residues in food and the environment is also required. WHO and FAO have jointly developed an International Code of Conduct on Pesticide Management. It guides government regulators, the private sector, civil society, and other stakeholders on best practices in managing pesticides throughout their lifecycle – from production to disposal. Pesticides that are most toxic to humans, as well as pesticides that remain for the longest time in the environment are banned. Maximum safe limits are set for pesticide residues in food and water, to protect public health. Micro Level Prevention Exposure to unsafe amounts of pesticides should be controlled. People engaged in spreading pesticides should be adequately protected and follow instructions for use. General Public entry should be restricted to areas where pesticides are spread. Food should comply with pesticide regulations, in particular with maximum residue limits. Peeling or washing fruit and vegetables can help consumers limit their intake of pesticide residues. Alternatives to Pesticides Certainly prevention is better than cure and use of Pesticides needs to be minimized. They should be used as the last resort only. Sustainable methods of Pest Control are being explored. Integrated Pest Management incorporates sustainable techniques to eliminate pests Eg. growing pest-resistant crop varieties, using predatory insects to kill plant-eating pests, mechanical pest traps, and eliminate pest nesting areas by plowing under harvested crops. Chemical and natural pesticides are used only as a last resort. Crop Rotation and other Growing Techniques such as planting crops in different places each season in order to replenish nutrients removed from the soil by a particular plant, and intercropping, a method of planting crops in close proximity. These practices help to break pest cycles, allow the soil to naturally replenish itself, help reduce weeds, and encourage plant diversity in order to avoid insect and pest infestation. Use of Organic Pesticides Organic pesticides were used before chemical ones took over. Natural, organic pesticides without harmful side effects can also be explored- such as Neem Salt Spray Mineral Oil Citrus Oil and Cayenne Pepper Soap, Orange Citrus Oil, and Water Eucalyptus Oil Onion and Garlic Spray Chrysanthemum Flower Tea Tobacco Spray Chile Pepper / Diatomaceous Earth and so on. Read more here: https://www.globalhealingcenter.com/natural-health/organic-pesticides/ Control of Pesticides in UAE All fresh produce and processed foods are tested by the ministry, in laboratories accredited by the British Commission for Accreditation, to ensure they meet international standards. While pesticide use is strictly controlled within the UAE, pesticides use in agriculture in other parts of the world affects UAE, as being a desert it has large imports of food products from world over. The Ministry of Climate Change and Environment in May, banned the import of certain fruits and vegetables from five countries in the Middle East over concerns about high chemical levels. These countries were also asked to submit necessary proof of compliance with international food safety standards before imports could resume. Read more here: https://www.thenational.ae/uae/uae-bans-import-of-fruits-and-vegetables-from-five-countries-1.17409 Other References http://www.who.int/mediacentre/factsheets/pesticide-residues-food/en/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984095/ https://www.niehs.nih.gov/health/topics/agents/pesticides/index.cfm https://medlineplus.gov/pesticides.html http://www.sustainabletable.org/263/pesticides http://www.sustainabletable.org/718/pesticides-if-this-doesn-t-convince-you-nothing-will |
