Follow up of workers previously exposed to silver solder containing cadmium
Follow up of workers previously exposed to silver solder containing cadmium
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DOI：
10.1136/oem.56.8.553
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发表时间：
1999-08-01
影响因子：
4.9
通讯作者：
Morgan, WD
中科院分区：
文献类型：
--
作者：
Mason, HJ;Williams, N;Morgan, WD
目的：对9名从事含镉焊料焊接多年的工人进行尿镉和血镉的纵向生物监测。方法采用中子活化法测定肝、肾组织中镉的含量，并于1983年和1995年进行肾功能评价。在此期间，通过局部排气通风控制和含镉焊料的替代，镉的暴露大大减少。结果：从尿蛋白测量的结果来看，有证据表明，在12年期间，该组患者的肾小管损伤有所增加，尽管在此期间，镉的暴露显著减少，并在1995年基本消除。没有证据表明血清肌酐降低了肾小球滤过率，肾小管对钙、磷或尿酸盐的处理也没有明显恶化。血和尿镉浓度在12年期间显着下降，但在1995年仍然很大。血镉浓度在低暴露数年的1995年趋于反映人体镉负荷，1983-90年下降最为显著。相比之下，尿镉浓度仅从1990年左右开始显着下降。1983或1995年尿镉与肝、肾镉浓度均无显著相关性。这可能是由于队列中肾小管功能障碍的程度所致。在12年期间计算的镉的累积排泄量大大大于在肝脏和肾脏中测量的镉的损失和身体负荷的衍生损失。讨论了产生这种现象的原因。在肾脏损害明显的队列中，尿镉浓度可能反映了当前暴露的一个重要组成部分，而不是储存的身体损失。结论--数据强化了这样一个概念，即血镉浓度可能不总是反映最近的暴露，但可能反映由历史暴露产生的身体负担，取决于当前暴露的程度；去除或减少暴露后，尿镉和血镉测量的下降将是缓慢的，并取决于历史的身体负担。
Objectives-To study longitudinal biological monitoring data on urinary and blood cadmium collected in a small cohort of nine workers who had been brazing for several years with solders containing cadmium.Methods-Cadmium was measured by neutron activation analysis in livers and kidneys, and estimates of renal function were carried out in 1983 and 1995. During the intervening period exposure to cadmium was dramatically reduced by local exhaust ventilation control and substitution of the solder containing cadmium.Results-From urinary protein measurements there was evidence within the group of increasing renal tubular damage over the 12 year period, even though exposure to cadmium was dramatically reduced over this period and almost eliminated by 1995. There was no evidence from serum creatinine of decreasing glomerular filtration rate, and the renal tubular handling of calcium, phosphate, or urate had not worsened significantly. Blood and urinary cadmium concentrations reduced significantly over the 12 year period but were still substantial in 1995. Blood cadmium concentrations tended to reflect cadmium body burden in 1995 when exposure had been low for several years, and decreased most significantly during 1983-90. By contrast urinary cadmium concentrations only decreased significantly from about 1990 onwards. Urinary cadmium was not significantly correlated with liver or kidney cadmium concentration in either 1983 or 1995. This may be due to the level of tubular dysfunction in the cohort. Calculated cumulative excretion of cadmium over the 12 year period was substantially greater than the loss of cadmium measured in Livers and kidneys and the derived loss in body burden. Reasons for this are discussed. It is possible that in cohorts, where renal damage is apparent, urinary concentrations reflect a substantial component of current exposure rather than stored body losses.Conclusions-The data reinforce the concept that blood cadmium concentrations may not always reflect recent exposure, but may reflect body burden derived from historical exposure depending on the degree of current exposure; and that the decline in urinary and blood cadmium measurements after removal from, or reduction in, exposure will be slow and depend on the historical body burden.