Al-Saleh Iman
Environmental Health Program, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia.
Biol Trace Elem Res. 2021 Dec;199(12):4535-4545. doi: 10.1007/s12011-021-02607-3. Epub 2021 Feb 5.
We previously measured the levels of inorganic mercury, methylmercury, lead, cadmium, and manganese in the breast milk of 203 healthy Saudi mothers who participated in a cross-sectional study between 2011 and 2013. The current study aimed to (1) calculate reference values (RVs) for these metals in breast milk based on the 95th percentile of the metal and the corresponding 95% confidence interval following the approach of the German Human Biomonitoring Commission, and (2) assess the health risk associated with these metals (except lead) by determining the hazard quotient (HQ) and hazard index (HI) for breastfed infants. The risk characterization for the lead was applied using the margin of exposure (MOE) approach. Moreover, the cancer risk (CR) associated with lead was calculated. The RVs (percentage of samples for which the value was higher than the set value) for inorganic mercury, methylmercury, total mercury, cadmium, lead, and manganese in breast milk (μg/L) were 1.5 (7.9%), 1.5 (5.4%), 2.8 (8.9%), 2.5 (8.4%), 53 (11.3%), and 22.3 (11.8%) μg/L, respectively. The methylmercury, lead, and manganese levels in the present study were higher than those reported previously. The HQ for methylmercury greater than 1 was found in 68.5% of the samples, indicating there may be a potential non-carcinogenic health risk of infant exposure to the toxic metal via breast milk consumption. Despite the high cadmium and manganese levels in breast milk, our results suggested no health risk (HQ < 1). The HI representing the combined non-carcinogenic health risk of four metals was > 1, with methylmercury (74%) being the major contributor. The estimated MOE mean value of 0.134, less than 1, indicates that our breastfed infants may be at increased risk of neurodevelopmental impairments. The CR for lead in two infants was higher than the acceptable level of 1 × 10. Although our results may suggest potential carcinogenic and non-carcinogenic risks of infant exposure to toxic metals through breast milk consumption, the benefits of breastfeeding are well recognized and outweigh the potential risks.
我们之前对203名参与了2011年至2013年横断面研究的沙特健康母亲的母乳中的无机汞、甲基汞、铅、镉和锰水平进行了测量。本研究旨在：(1) 根据德国人体生物监测委员会的方法，基于金属的第95百分位数及其相应的95%置信区间，计算母乳中这些金属的参考值(RV)；(2) 通过确定母乳喂养婴儿的危害商数(HQ)和危害指数(HI)，评估与这些金属(铅除外)相关的健康风险。铅的风险特征采用暴露边际(MOE)方法进行评估。此外，还计算了与铅相关的癌症风险(CR)。母乳中无机汞、甲基汞、总汞、镉、铅和锰的参考值(高于设定值的样本百分比)(μg/L)分别为1.5(7.9%)、1.5(5.4%)、2.8(8.9%)、2.5(8.4%)、53(11.3%)和22.3(11.8%)μg/L。本研究中甲基汞、铅和锰的水平高于之前报道的水平。在68.5%的样本中发现甲基汞的HQ大于1，这表明婴儿通过食用母乳接触这种有毒金属可能存在潜在的非致癌健康风险。尽管母乳中镉和锰的含量很高，但我们的结果表明没有健康风险(HQ<1)。代表四种金属综合非致癌健康风险的HI>1，其中甲基汞(74%)是主要贡献者。估计的MOE平均值为0.134，小于1，这表明我们的母乳喂养婴儿可能面临神经发育障碍风险增加的情况。两名婴儿的铅CR高于可接受水平1×10。尽管我们的结果可能表明婴儿通过食用母乳接触有毒金属存在潜在的致癌和非致癌风险，但母乳喂养的益处是众所周知的，且超过了潜在风险。
