The Impact of Pesticides - Academy Publish

exposed populations, revealed high suicide rates in farming populations.Epidemiological studies conclude that acute and chronic OP exposure is associatedwith affective disorders (London et al., 2005; Jaga and Dharmani, 2007).The underlying mechanism of COPIND has not been established. Tan et al. (2009)hypothesized that COPIND could be derived from withdrawal of OP pesticide afterchronic low-level exposure or acute exposure. In addition, other scientists havesuggested that mechanisms other than the inhibition of AChE might also beinvolved. Ray (1998) hypothesized that some protein targets present in brain, knownto be sensitive to a number of OP compounds, may be changed even after low levelexposure exerting both favorable and damaging manner. Several animal studieshave shown that cognitive enhancing action of low doses of certain OPs, such asdichlorvos, in rats were unrelated to AChE inhibition. It was suggested that OPcompounds may affect neuropeptide metabolism through the release of endogenousopiates and/or through interactions with yet unidentified receptors (Kohen et al.,1980; Kubek et al., 1997; Desi and Nagymajtényi, 1999). It has also been observedthat administration of different OP compounds has different behavioral presentation,suggesting that observed effects are not entirely a result of AChE inhibition (VanDongen and Wolthuis, 1989; Pope et al., 1992). Finally, London et al. (2005)reported that exposure to OP may cause serotonin disturbances in the centralnervous system, which are implicated in depression and suicide in humans (Londonet al., 2005).MEDICAL MANAGEMENT OF PATIENTS WITH CHOLINERGICSYNDROME CAUSED BY ORGANOPHOSPHORUS PESTICIDESGeneral MeasuresTreatment of OP pesticide poisoning should begin with decontamination andresuscitation if needed. Decontamination is vital in reducing the dose of thepesticide absorbed, but care must be taken not to contaminate others, such asmedical and paramedical workers. In the case of ingestion, lavage can be performed,and activated charcoal administered. The patient should be observed carefullyduring the early stages of treatment because respiratory arrest may occur. Solventvehicles and other components of the formulated OP pesticide may complicate theclinical picture and should be taken into consideration (IPCS, 1998).Supportive measures should be directed towards the cardiorespiratory system withparticular emphasis on maintenance of ventilation, cardiac rhythm and bloodpressure; the removal by suction of respiratory and oral secretions which may causerespiratory distress; and the oxygenation of the patient. Severely poisoned patientsdisconnected from the ventilator when the general condition improves, must becarefully watched for rapid deterioration and development of the intermediatesyndrome during the following few days in the Intensive Care Unit (IPCS, 1998). Inaddition, the patients should be warned to report to hospital if signs oforganophosphate-induced delayed polyneuropathy appear 2-3 weeks after exposure.Ingested organophosphates should be removed by early gastric aspiration and thenlavage, with protection of the airway because they are mostly dissolved in aromatichydrocarbons; this may be the best remedy in unconscious patients. Gastric lavage ismost effective within 30 minutes of ingestion, but might be still effective up to 4hours post ingestion, as organophosphates are rapidly absorbed from thegastrointestinal tract (WHO, 1986).Administration of oral activated charcoal, in conventional doses, may be consideredfor reducing further absorption of some organophosphorus pesticides (WHO, 1986).AcademyPublish.org - The Impact of Pesticides46