Trevisan A, Nicoletto G, Maso S, Grandesso G, Odynets A, Secondin L
Laboratorio di Tossicologia Industriale, Università di Padova, Italy.
Int Arch Occup Environ Health. 1994;65(6):373-5. doi: 10.1007/BF00383246.
Concentration-dilution of spot urine samples is a shortcoming of the biological monitoring of industrial xenobiotics. To ascertain whether the adjustment of urinary cadmium measured in spot samples is appropriate, urine samples were taken three times, once a week for 3 successive weeks, from 25 welders employed in the manufacture of jewelry (total 75 samples). Cadmium, creatinine, specific gravity, total urinary solutes, urinary volume and urinary flow rate were measured in 12-h collections and in spot samples taken immediately afterwards. Creatinine and total urinary solutes showed high inverse correlation with urinary flow rate (r = -0.858 and r = -0.768 respectively). Urinary cadmium displayed a similar trend but the correlation was not significant (r = -0.145). Creatinine adjustment of urinary cadmium values in spot samples increased the correlation with the same index in timed samples adjusted for urinary volume (r = -0.808) or urinary flow rate (r = 0.821) compared with non-adjustment (r = 0.732 and r = 0.738, respectively). Creatinine adjustment of spot sample values is also suitable for a wide range of urinary concentrations; discarding excessively diluted or concentrated urines, correlation of urine samples improved for non-adjusted or specific gravity-adjusted values, whereas no changes were observed for creatinine-adjusted values.
随机尿样的浓缩稀释是工业外源性物质生物监测的一个缺点。为确定随机样本中测量的尿镉调整是否合适，从25名从事珠宝制造的焊工中连续3周每周采集一次尿样，共采集3次（总计75个样本）。在12小时的尿液收集样本以及随后立即采集的随机样本中测量镉、肌酐、比重、尿总溶质、尿量和尿流率。肌酐和尿总溶质与尿流率呈高度负相关（分别为r = -0.858和r = -0.768）。尿镉呈现类似趋势，但相关性不显著（r = -0.145）。与未调整（分别为r = 0.732和r = 0.738）相比，随机样本中尿镉值经肌酐调整后，与按尿量（r = -0.808）或尿流率（r = 0.821）调整的定时样本中相同指标的相关性增加。随机样本值的肌酐调整也适用于广泛的尿浓度范围；丢弃过度稀释或浓缩的尿液后，未调整或经比重调整的值的尿样相关性提高，而经肌酐调整的值未观察到变化。
