Effects Of Occupational Exposure To Benzo[a]pyrene On The Nervous System Functions And The Level Of Amino Acids In Plasm In Coke Oven Workers

Objective To explore the effect of occupational exposure to benzo[a]pyrene(B[a]P)on the neurobehavioral function among coke oven workers,and to find the peripheral specific effect biomarker.Methods:1.Determination of exposure level.Healthy adult male workers were selected from a coke plant and the native material plant of one state-owed enterprise in Taiyuan City.①B[a]P concentration in the work environment was monitored;②Blood and urine samples were collected immediately after a shift at the end of a working day.The urinary 1-hydroxypyrene(HpU)level was measured using High Performance Liquid Chromatography (HPLC).2.Test of ANS functions.According to their urinary 1-hydroxypyrene(HpU)level,the investigated workers were classified into three groups:low-dose group(LDG),mid-dose group (MDG)and high-dose group(HDG).①The workers' general informations needed were collected by query and filled in the questionnaire by special investigators who were specially trained according to the same criteria.The questionnairewe designed contained the following iterms:age,gender,birth date,education,type and length of work in production,tobacco and alcohol consumption,living habits,history of work-exchanging,history of medicine-taking, history of personnel and family,and especially symptomes;②The variation of the workers' heart rate and blood pressure were measured by adopting the Autonomic Nervous Systerm(ANS) function testing system recommended by Ewing DJ.3.Test of neurobehavioral variations.WHO recommended NCTB were performed on workers to test the mood state and neurobehavioral functions on coke oven workers and controls.4.Determination of Amino Acids in plasm Four Amino Acids transmitter levels in plasm (including Glutamate,Aspartate,Gamma-aminobutyric and Glycine)were measured using High Performance Liquid Chromatography(HPLC).Results:No significant differences were found among three groups in age,length of service,education,smoking and drinking.1.There were no significant differences in the scores of the symptomes of nervous system(SNS),the symptomes of digestive system(SDS)and the symptomes of skeletal muscular system(SMS)compared to those of LDG(P＞0.05).However,there were significant differences in the scores of the symptomes of endocrine system(SES)and cardiovascular system(CVS)(P＞0.05).2.Compared with LDG,the workers of MDG and HDG showed significant differences in HR-V((P＜0.01)and R-R30:15(P＜0.05),insignificant differences in BP-IS(P＞0.05),higher scores on negative mode state,and lower scores on positive mode state,poorer performance in auditomemory and attention in NCTB test(P＜0.05),significant differences in Asp((P＜0.01)in plasm,insignificant differences in Glu(P＞0.05).This study revealed that,the level of Asp in plasm had negative correlation with urinary 1-hydroxypyrene(HpU)level,and the score of Digit span had positive correlation with the level of Asp in plasm.Conclusion:1.Benzo[a]pyrene possesses neurotoxicity.It can induce the changes neurobehavioral and autonomic nervous system function。2.The level of Asp in plasm was correlated with the The urinary 1-hydroxypyrene(HpU) for the occupational exposure to benzo[a]pyrene.