空气苯浓度与呼出苯及尿酚的关系研究

目的对苯接触水平和接触者可能受到的有害影响进行卫生学评价。方法对１０名苯接触者和６名志愿苯接触者进行研究，用苯呼出气作为生物学监测指标。结果班前呼出苯大多为未检出，班中及班后呼出苯与空气苯时间加权平均浓度均有密切相关；班前尿酚与空气苯时间加权平均浓度无相关，班后尿酚及次晨尿酚均与空气苯ＴＷＡ浓度密切相关；班中、班后呼出苯均与班后尿酚及次晨尿酚密切相关，且以班中呼出苯与班后尿酚的相关性最高（ｒ＝０．９３５３）。呼出苯的快速排出相为脱离接触１０分钟（占班后呼出苯８２．２５％），其排出稳定相在脱离接触后９０分钟左右。接触空气苯浓度ＴＷＡ７．９～２１７．８ｍｇ／ｍ３时，无论是呼出苯或尿酚在接触后２４小时与空气苯均无相关。结论在呼出苯的快速排出相采集终末呼出气可反映工人当时的接触浓度，采集排出稳定相终末呼出气，其浓度较稳定可反映接触者吸收入血液的浓度，并以此来估测环境浓度与接触水平。呼出苯的呼吸排出规律以及采样方便、无损伤，检出灵敏，呼出苯作为接触水平监测指标较其他指标优越。

A study on alveolar air of subjects exposed to benzene as a biological monitoring indicator

Objective To evaluate the exposure levels and the possible effects of benzene to subjects exposed using alveolar air as a biological monitoring indicator. Methods 10 workers and 6 volunteers exposed to benzene were selected for sampling alveolar air and analyzing its concentration of benzene. Results The benzene of alveolar air in all subjects was negative at the pre --*3] shift. However,it was found the time - weighted average (TWA) benzene levels in the air at workshops significantly correlated with the benzene concentration of the alveolar air at mid - shift and post - shift.There was no relationship between the phenol levels in the urine at pre - shift and the time weighted average benzene levels (TWA) in the air;but a close correlation between the phenol levels in the urine at postT7] - shift and the next morning with the benzene levels(TWA)in the air at workshops were found.The benzene concentrations of the alveolar air at mid -3] shift and post - shift significantly correlated with the phenol levels in the urine at post -*3]- shift and the next morning,especially,between the benzene concentrations of the alveolar air at mid - shift with phenol levels in urine at post - shift( r =0.9353).The fast phase of benzene exhaled from the alveolar air was 10 min.after cessation of exposure which accounted for 82.25% of total amount of benzene exhaled from the alveolar air at post - shift.The stable phase of benzene exhaled was about 90min after cessation of exposure. Conclusion The benzene level of the alveolar air exhaled at the stable phase could reflect the blood level of benzene absorbed into the body ,and could be used as a good indicator of the exposure level.