[The neurobehavioral effects of population occupationally exposed to ethylbenzene].

OBJECTIVE

To evaluate the influence of ethylbenzene on the neurobehavior of occupationally exposed workers.

METHODS

The exposure group consisted of 246 workers occupationally exposed to ethylbenzene and 172 staffs from the offices served as controls. The basic information on ethylbenzene exposure was collected by the questionnaire. The nervous behavior and function of workers were evaluated by Neurobehavioral Core Test Battery (NCTB).

RESULTS

There were no differences of the scores for four emotional states (tension, depression, angry and bewilderment) between exposure group and control group (P > 0.05). The score of emotion (vigor) in exposure group was significantly lower than that in control group (P < 0.05), but the fatigue score in exposure group was significantly higher than that in control group (P < 0.05). The score of mean reaction time in exposure group was significantly higher than that in control group (P < 0.05), the scores of digital span, manual dexterity, visual retention and target tracking in exposure group were significantly lower than those in control group (P < 0.05). The exposure group was divided into 5 sub-groups, according to working duration. There were no differences for the scores of visual retention and target tracking among 5 sub-groups (P > 0.05). The scores of five emotional states (tension, depression, angry, fatigue and bewilderment) in 3 sub-groups exposed to ethylbenzene for 3 ∼, 4 ∼ and 5 ∼ years were significantly higher than those in 2 sub-groups exposed to ethylbenzene for 0 ∼ and 2 ∼ years (P < 0.05). The scores of digital span in 2 sub-groups exposed to ethylbenzene for 3 ∼ or 4 ∼ years and the scores of manual dexterity and digital symbol in 3 sub-groups exposed to ethylbenzene for 3 ∼, 4 ∼ and 5 ∼ years were significantly lower than those in 2 sub-groups exposed to ethylbenzene for 0 ∼ and 2 ∼ years (P < 0.05).

CONCLUSIONS

Ethylbenzene can depress the neurobehavioral functions of exposed workers. The neurobehavioral functions of workers exposed to ethylbenzene for 3 years changed significantly. The workers exposed to ethylbenzene for 3 years may be the susceptible population of neurobehavioral function impairment.