title: The effects of occupational exposure to chlorpyrifos on the neurologic examination of central nervous system function: a prospective cohort study.
abstract: Questions persist about adverse effects such as impaired cognition and attention, incoordination, spasticity, or parkinsonism from chronic, low-level exposures to organophosphate (OP) compounds. In a prospective cohort study, we evaluated chlorpyrifos-manufacturing workers and a referent group on 2 occasions, 1 year apart, to determine whether occupational exposure to chlorpyrifos produced clinically evident central nervous system (CNS) dysfunction. Chlorpyrifos subjects had significantly higher TCP excretion and lower average BuChE activity than referents in a range in which physiological effects on B-esterases exist. Few subjects had neurologic symptoms or signs, and there were no significant group differences in terms of signs at baseline or second examinations. Chronic chlorpyrifos exposure produced no clinical evidence of cortical, pyramidal tract, extrapyramidal, or other CNS dysfunction among chlorpyrifos subjects compared with referents, either at baseline or after 1 year of additional chlorpyrifos exposure.
authors.affiliation: Department of Neurology, University of Michigan Health Systems, Ann Arbor 48109-0032, USA. jwalbers@umich.edu
authors.forename: James W
authors.initials: JW
authors.lastname: Albers
authors.forename: Stanley
authors.initials: S
authors.lastname: Berent
authors.forename: David H
authors.initials: DH
authors.lastname: Garabrant
authors.forename: Bruno
authors.initials: B
authors.lastname: Giordani
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Schweitzer
authors.forename: Richard P
authors.initials: RP
authors.lastname: Garrison
authors.forename: Rudy J
authors.initials: RJ
authors.lastname: Richardson
mesh_terms: D000328:Adult; D015415:Biomarkers; D002091:Butyrylcholinesterase / Q000652:urine; D016022:Case-Control Studies; D002617:Chemical Industry; D004390:Chlorpyrifos / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007306:Insecticides / Q000009:adverse effects* / Q000032:analysis; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D009422:Nervous System Diseases / Q000139:chemically induced* / Q000453:epidemiology; D009460:Neurologic Examination; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D011446:Prospective Studies; D011728:Pyridones / Q000652:urine
chemical_list: D015415:Biomarkers; D007306:Insecticides; D011728:Pyridones; C012587:3,5,6-trichloro-2-pyridinol; D002091:Butyrylcholinesterase; D004390:Chlorpyrifos