Schumacher C, Brodkin C A, Alexander B, Cullen M, Rainey P M, van Netten C, Faustman E, Checkoway H
University of Washington, Department of Environmental Health, Seattle 98104, USA.
Int Arch Occup Environ Health. 1998 Oct;71(7):453-8. doi: 10.1007/s004200050305.
To evaluate the effect of low to moderate occupational lead exposure on thyroid function we conducted a cross-sectional study of 151 male lead smelter workers.
Parameters of thyroid function were assessed in relation to both subacute and cumulative lead exposure over a 10-year employment period. Blood lead levels, obtained from plant surveillance records, were used to establish four ordinal levels of current and cumulative exposure (< 15, 15-24, 25-39, and > or =40 microg/dl).
Mean values for the lowest as compared with the highest current exposure group were similar for thyroxine (T4: 6.8 versus 6.1 microg/dl), estimated free thyroxine (EFT4: 1.6 ng/dl in both groups), and thyroid-stimulating hormone (TSH: 1.8 versus 1.7 mIU/l); there was no evidence of a significant trend for diminished thyroid function associated with increasing current lead exposure. Similarly, no significant difference was observed for T4, EFT4, or TSH in relation to the 10-year cumulative exposure or for adjusted analyses controlling for potential confounders, including age and alcohol use.
In contrast to studies observing thyroid dysfunction in the setting of high lead exposure and related clinical poisoning, our findings weigh against a significant physiologic effect on thyroid function at lower levels (< 60 microg/dl) of occupational lead exposure.
为评估低至中度职业性铅暴露对甲状腺功能的影响，我们对151名男性铅冶炼工人进行了一项横断面研究。
在10年的工作期间，评估甲状腺功能参数与亚急性和累积铅暴露的关系。从工厂监测记录中获取的血铅水平用于确定当前和累积暴露的四个顺序水平（<15、15 - 24、25 - 39和≥40微克/分升）。
与最高当前暴露组相比，最低暴露组的甲状腺素（T4：6.8对6.1微克/分升）、估计游离甲状腺素（两组均为1.6纳克/分升）和促甲状腺激素（TSH：1.8对1.7毫国际单位/升）的平均值相似；没有证据表明甲状腺功能随着当前铅暴露增加而有显著下降趋势。同样，在10年累积暴露方面，或在控制包括年龄和饮酒等潜在混杂因素的调整分析中，T4、EFT4或TSH均未观察到显著差异。
与在高铅暴露和相关临床中毒情况下观察到甲状腺功能障碍的研究相反，我们的研究结果不支持职业性铅暴露水平较低（<60微克/分升）时对甲状腺功能有显著生理影响的观点。
