Since we shifted from hunter-gatherer and nomadic pastoralist lifestyles to an agricultural-based one, we have consistently sought after improved technologies to aid food production.  The development of agricultural chemicals not only revolutionized agriculture, but affected all forms of life on this planet.

         The first artificial fertilizer was introduced in the 1840s.  Superphosphates were developed in England as the result of treating phosphate rock with sulfuric acid.  The first inorganic insecticides also appeared at about this time.  Inorganic insecticides were composed of arsenic, copper, lead, manganese, zinc and other minerals, pyrethrum from dried chrysanthemums, nicotine sulfate and rotenone.  These inorganic insecticides, however, were not nearly as potent as those of a century later.

         World War II marked the invention of a whole new sort of chemical–those made by lab manipulation of molecules.  Suddenly, certain atoms could be substituted and the arrangement of atoms in a molecule could be altered.  These new, powerful synthetic chemicals were employed for chemical warfare during WWII.  When the war was over, scientists found that these same chemicals also kill insects.  They were marketed as insecticides.

         There are two categories of synthetic insecticides: chlorinated hydrocarbons and organic phosphorous insecticides.  The most common example of the former is DDT, while well-known examples of the latter are malathion and parathion.  Although this technological chemical revolution has helped farmers increase their yields, the introduction of synthetic chemicals into the ecosystem has had horrific results.  Synthetic agricultural chemicals are poison in rivers, streams, groundwater, soil, fish, reptiles, earthworms and other animals, bird eggs and breast milk.[1]  In the human body, many of these chemicals destroy enzymes that keep us healthy, prevent the normal functioning of various organs, cause cancer or create a variety of other problems.[2]

         An example of what was once one of the most commonly used, most toxic agricultural chemicals is DDT, an insecticide and ingredient in household products.  DDT was first discovered in 1874.  However, its properties weren't recognized until 1939.  Its use was banned within the United States in 1972.  It was initially viewed as harmless; during WWII it was dusted over the heads of soldiers to exterminate lice.[3] Although there were no immediate problems, DDT soon revealed its horrendous effects on the human body.  Cancer, reproductive toxicity and liver problems are all common long-term effects of this poisonous chemical.[4]

         DDT also proved poisonous to other life forms.  In 1962, Rachel Carson published her book Silent Spring in which she reveals problems caused by DDT.  Carson noticed that springtime in certain parts of the country was oddly silent, for many of the birds were dead.  Her research finally led her to discover that DDT had poisoned the birds, causing their egg shells to be thin and their children to die.

         Research done on numerous other chemicals whose residues can be found in fruits and vegetables shows that many chemicals create problems like those caused by DDT.  For example, Captan, a fungicide found in peaches, strawberries, apples and other fruits, has been shown to cause cancer and mutagenicity.[5]  Permethrin, found in lettuce, cabbage and tomatoes, creates cancer and reproductive toxicity.[6]

         Not only are agricultural chemical poisons being released into our ecosystem intentionally, but they are accidentally as well.  One of the most tragic acts of negligence occurred on December 3, 1984.  Due to unsafe practices, Union Carbide Corporation in Bhopal, India, inadvertently leaked methyl isoryanate gas (MIC) from its tank.[7] The heavy, yellow noxious gas spread over the city of 800,000.  Most were permanently wounded or killed.[8]

         Despite such irrefutable proof condemning many synthetic chemicals, chemical industries continue to produce dangerous agricultural chemicals.  Additionally, non-organic farmers use an increasing number and variety of agricultural chemicals yearly.  In spite of this very grim picture, there is hope for the future of agriculture as evidenced by the growing support for organic agriculture.

 

         A timeline of the development of farm machineries and technologies has been developed by Economic Research Service.  It can be viewed at:  www.usda.gov/history2/text4.htm