Neuropsychiatric Evaluation in Subjects Chronically Exposed to Organophosphate Pesticides

• Published in: Toxicological sciences Vol. 72; no. 2; pp. 267 - 271
• Main Authors: Salvi, Rosane Maria, Lara, Diogo R., Ghisolfi, Eduardo S., Portela, Luis V., Dias, Renato D., Souza, Diogo O.
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 01.04.2003
• Subjects: acetylcholinesterase; Acetylcholinesterase - blood; Adult; Agricultural Workers' Diseases - blood; Agricultural Workers' Diseases - epidemiology; Agricultural Workers' Diseases - etiology; Biological and medical sciences; Brazil - epidemiology; Cognition Disorders - blood; Cognition Disorders - epidemiology; Cognition Disorders - etiology; Epidemiologic Studies; Female; Humans; Insecticides - adverse effects; Male; Medical sciences; Occupational Exposure; organophosphate pesticides; Organophosphorus Compounds; parkinsonism; Pesticides, fertilizers and other agrochemicals toxicology; psychiatry; Psychomotor Disorders - blood; Psychomotor Disorders - epidemiology; Psychomotor Disorders - etiology; Toxicology; South America; Brazil; America; Nervous system diseases; parkinsonism; Enzyme; Toxicity; organophosphate pesticides; Pesticides; Parkinson disease; Esterases; psychiatry; Acetylcholinesterase; Occupational exposure; Carboxylic ester hydrolases; Cerebral disorder; Chronic; Enzymatic activity; Central nervous system disease; Mental disorder; Hydrolases; Agriculture; Degenerative disease; Organophosphorus compounds; Occupational medicine
• DOI: 10.1093/toxsci/kfg034
• ISSN: 1096-6080; 1096-0929

Long-term exposure to low levels of organophosphate pesticides (OP) may produce neuropsychiatric symptoms. We performed clinical, neuropsychiatric, and laboratory evaluations of 37 workers involved in family agriculture of tobacco from southern Brazil who had been exposed to OP for 3 months, and in 25 of these workers, after 3 months without exposure to OP. Plasma acetylcholinesterase activity levels of all subjects were within the normal range (3.2 to 9.0 U/l) and were not different between on- and off-exposure periods (4.7 ± 0.9 and 4.5 ± 1.1 U/l, respectively). Clinically significant extrapyramidal symptoms were present in 12 of 25 subjects, which is unexpected in such a population. There was a significant reduction of extrapyramidal symptoms after 3 months without exposure to OP, but 10 subjects still had significant parkinsonism. Mini-mental and word span scores were within the expected range for this population and were not influenced by exposure to OP. Eighteen of the 37 subjects (48%) had current psychiatric diagnoses in the first interview (13 with generalized anxiety disorder and 8 with major depression). Among the 25 subjects who completed both evaluations, the total number of current psychiatric diagnoses, after 3 months without using OP, dropped from 24 to 13 and the number of affected individuals with any psychiatric diagnosis dropped from 11 to 7. In conclusion, this study reinforces the need for parameters other than acetylcholinesterase activity to monitor for chronic consequences of chronic low-dose OP exposure, and it suggests that subjects have not only transient motor and psychiatric consequences while exposed, but may also develop enduring extrapyramidal symptoms.