Evaluation of acute sensory-motor effects and test sensitivity using termiticide workers exposed to chlorpyrifos

Sensory and motor testing was performed on a group of termiticide workers p rimarily using chlorpyrifos-containing products to evaluate both the acute effects from current exposure and sensitivity of the measures to detect eff ects. The study group comprised 106 applicators and 52 nonexposed participa nts. Current exposure was measured by urinary concentrations of 3,5,6-trich loro-2-pyridinol (TCP) collected the morning of testing. The mean TCP value for the 106 applicators was 200 mug/g creatinine. Participants received 4- 5 h of testing and were evaluated using a sensory-motor test battery recomm ended by a National Institute for Occupational Safety and Health (NIOSH)-sp onsored advisory panel to be appropriate for testing effects from pesticide exposures. Measurements testing olfactory dysfunction, visual acuity, cont rast sensitivity, color vision, vibrotactile sensitivity, tremor, manual de xterity, eye-hand coordination, and postural stability were analyzed. Study results indicated limited acute effects from exposure to chlorpyrifos usin g urinary TCP as a measure of current exposure, The effects occurred primar ily on measures of postural sway in the eyes closed and soft-surface condit ions, which suggests a possible subclinical effect involving the propriocep tive and vestibular systems. Several other tests of motor and sensory funct ions did not show any evidence of acute exposure effects, although statisti cally significant effects of urinary TCP on the Lanthony color vision test scores and one contrast sensitivity test score were found. The visual measu res, however, were not significant when a step-down Bonferroni correction w as applied. Information also is presented on the sensitivity of the measure s to detect effects in an occupationally exposed population using standard error of the parameter estimates. (C) 2001 Elsevier Science Inc. All rights reserved.