The Impact of Pesticides - Academy Publish

acetylcholine, a neurotransmitter that acts in the transmission of nerve impulses inmuscle fibers (Casaret, Doull et al. 2001).The presence of acetylcholinesterase isused as a biological index of exposure to organophosphorus and carbamatepesticides (Rama and Jaga 1992).In a study conducted in northern South Africa, itwas evaluated the exposition of coffee producers to the pesticides: parathion,monocrotophos, dicrotphos, trichlorfon, disulfoton, benomyl, mancoseb, maneb,zineb, bipyridals, paraquat-p-butyl fluazfop, glyphysate, copperoxychloride,miname and chlordane (Rama and Jaga 1992), by determining enzyme activity ofacetylcholinesterase in red blood cells and blood plasma. The results obtained fromanalysis of red blood cells showed that 77% of workers presentedacetylcholinesterase levels below those considered normal by legislation of theRepublic of South Africa. There were also decreased levels of plasmaacetylcholinesterase in 27% of the blood samples analyzed (Fuller and Berger 1990;Rama and Jaga 1992).The study of Jacobson et al. (2009), state of Espírito Santo, Brazil, also showed arelationship between the use of organophosphorus pesticides and neurologicalproblems, since workers have reported problems with depression and memory loss(Jacobson, Hacon et al. 2009).Abusive use of pesticides can contaminate air, soil, water, as well as fauna and flora.This was reported in the study performed by Garcia et al.(2006), where theapplication of pesticides in coffee plantations of the Sierra Madre de Chiapas,Mexico, resulted in a reduction in the number of bats. In this region there is avariety of bat species due to tree cover and shading of coffee plantations thatprovide conditions similar to original forest. However, in coffee plantations sprayedwith large amounts of the insecticide Thiodan (endosulfan) used in the chemicalcontrol of the Coffee Berry Borer (Hypothenemushampei) a reduction in the numberof bats was observed, since these insects are important components of their diet(Garcia Estrada, Damon et al. 2006).Similarly, Ellis-Tabanore and Hyslop (2005) reported that in Jamaica, farmers usedorganochlorine insecticides to combat the Coffee Berry Borer. Results of the studyshowed a reduction in the number of snails of the species Thiara granifera (familyThiaridae) living in rivers of the coffee producing regions. These sites werecontaminated with endosulfam. This led the authors to propose that snails of thespecies Thiara can be used as an indicator of polution levels resultant of pesticidespresent in rivers or streams (Ellis-Tabanor and Hyslop 2005).ANALYTICAL METHODS TO ASSESS EXPOSURE TOPESTICIDES USED IN COFFEESample PreparationThe methods for extraction of pesticides and clean-up of food and environmentalsamples are extremely important for their quantitative determination in the matricesof interest. Extraction techniques used to concentrate the analytes include liquidliquidextraction (LLE), solid phase extraction (SPE), single-drop microextraction(SDME) and solid phase microextraction (SPME) (Souza, Amorin et al. 2010).The LLE extraction is based on the partition of the sample between two immisciblephases (organic and aqueous) and is often used in the analysis of pesticides in waterand food samples.Solid phase extraction (SPE) was introduced in 1978 as an alternative to LLE. Theanalytes contained in an aqueous matrix are extracted for their acquisition with theinterfering compounds after passage through a sorbent cartridge. A selective organicAcademyPublish.org - The Impact of Pesticides382