Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany.
J Toxicol Environ Health A. 2012;75(8-10):508-14. doi: 10.1080/15287394.2012.675301.
The reproductive toxicity of boric acid and borates is a matter of current regulatory concern. Based on experimental studies in rats, no-observed-adverse-effect levels (NOAELs) were found to be 17.5 mg boron (B)/kg body weight (b.w.) for male fertility and 9.6 mg B/kg b.w. for developmental toxicity. Recently, occupational human field studies in highly exposed cohorts were reported from China and Turkey, with both studies showing negative results regarding male reproduction. A comparison of the conditions of these studies with the experimental NOAEL conditions are based on reported B blood levels, which is clearly superior to a scaling according to estimated B exposures. A comparison of estimated daily B exposure levels and measured B blood levels confirms the preference of biomonitoring data for a comparison of human field studies. In general, it appears that high environmental exposures to B are lower than possible high occupational exposures. The comparison reveals no contradiction between human and experimental reproductive toxicity data. It clearly appears that human B exposures, even in the highest exposed cohorts, are too low to reach the blood (and target tissue) concentrations that would be required to exert adverse effects on reproductive functions.
硼酸和硼酸盐的生殖毒性是当前监管关注的问题。基于大鼠的实验研究，发现雄性生育力的无观察不良效应水平（NOAEL）为 17.5 毫克/千克体重（b.w.）硼，发育毒性的 NOAEL 为 9.6 毫克/千克 b.w.。最近，中国和土耳其报告了来自高暴露人群的职业人群现场研究，这两项研究都表明男性生殖能力呈阴性结果。将这些研究的条件与实验性 NOAEL 条件进行比较是基于报告的 B 血水平，这显然优于根据估计的 B 暴露情况进行的缩放。估计的每日 B 暴露水平与测量的 B 血水平的比较证实了生物监测数据更适合于比较人体现场研究。一般来说，环境中 B 的高暴露水平低于可能的高职业暴露水平。比较结果表明，人类和实验性生殖毒性数据之间没有矛盾。显然，即使在暴露水平最高的人群中，人类 B 的暴露水平也太低，无法达到对生殖功能产生不良影响所需的血液（和靶组织）浓度。
