Krins A, Karcher K, Nosske D, Sahre P, Schönmuth T
VKTA/Nuclear Engineering and Analytics Rossendorf Inc., Postfach 510119, D-01314 Dresden, Germany.
Radiat Prot Dosimetry. 2003;104(2):139-52. doi: 10.1093/oxfordjournals.rpd.a006174.
Based on existing pharmacokinetic models for benzene, the distribution and retention of activity after inhalation of 14C-labelled benzene in humans were studied. Six different benzene concentrations from 0.1 to 10,000 ppm (corresponding to activity concentrations between 9.6 x 10(6) and 9.6 x 10(11) Bq m(-3)) and five exposure times from 0.1 to 1000 min were considered. The cumulated activities in the different organs and tissues and the urinary excretion rates were observed to depend non-linearly on the activity intake. The fraction of activity removed via urine varies between 52 and 10% of the intake. Nevertheless, for times that are long compared to the exposure duration the urinary excretion rate is determined by the activity clearance from adipose tissue and thus decreases at a constant rate. This decrease is common for all exposure conditions examined and thus allowed determining a mean urinary excretion rate and corresponding dose coefficients for committed equivalent doses as well as for the effective dose. The uncertainty of the dose coefficients is estimated to be about 50% for the exposure range covered. A 14-day interval for the incorporation monitoring by urine activity counting seems to be reasonable.
基于现有的苯的药代动力学模型，研究了人体吸入14C标记的苯后活性物质的分布和滞留情况。考虑了六种不同的苯浓度，范围从0.1到10,000 ppm（对应于9.6×10(6)至9.6×10(11) Bq m(-3)之间的活性浓度）以及五种暴露时间，从0.1到1000分钟。观察到不同器官和组织中的累积活性以及尿排泄率非线性地依赖于活性摄入量。经尿液排出的活性部分占摄入量的52%至10%不等。然而，对于与暴露持续时间相比很长的时间，尿排泄率由脂肪组织中的活性清除率决定，因此以恒定速率下降。这种下降在所有检查的暴露条件下都是常见的，因此可以确定平均尿排泄率以及相应的剂量系数，用于计算待积当量剂量和有效剂量。在所涵盖的暴露范围内，剂量系数的不确定性估计约为50%。通过尿液活性计数进行14天的摄入监测间隔似乎是合理的。
