Berglund Marika, Lind Birger, Björnberg Karolin Ask, Palm Brita, Einarsson Osten, Vahter Marie
Department of Metals and Health, Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden.
Environ Health. 2005 Oct 3;4:20. doi: 10.1186/1476-069X-4-20.
Biomarkers for mercury (Hg) exposure have frequently been used to assess exposure and risk in various groups of the general population. We have evaluated the most frequently used biomarkers and the physiology on which they are based, to explore the inter-individual variations and their suitability for exposure assessment.
Concentrations of total Hg (THg), inorganic Hg (IHg) and organic Hg (OHg, assumed to be methylmercury; MeHg) were determined in whole blood, red blood cells, plasma, hair and urine from Swedish men and women. An automated multiple injection cold vapour atomic fluorescence spectrophotometry analytical system for Hg analysis was developed, which provided high sensitivity, accuracy, and precision. The distribution of the various mercury forms in the different biological media was explored.
About 90% of the mercury found in the red blood cells was in the form of MeHg with small inter-individual variations, and part of the IHg found in the red blood cells could be attributed to demethylated MeHg. THg in plasma was associated with both IHg and MeHg, with large inter-individual variations in the distribution between red blood cells and plasma. THg in hair reflects MeHg exposure at all exposure levels, and not IHg exposure. The small fraction of IHg in hair is most probably emanating from demethylated MeHg. The inter-individual variation in the blood to hair ratio was very large. The variability seemed to decrease with increasing OHg in blood, most probably due to more frequent fish consumption and thereby blood concentrations approaching steady state. THg in urine reflected IHg exposure, also at very low IHg exposure levels.
The use of THg concentration in whole blood as a proxy for MeHg exposure will give rise to an overestimation of the MeHg exposure depending on the degree of IHg exposure, why speciation of mercury forms is needed. THg in RBC and hair are suitable proxies for MeHg exposure. Using THg concentration in plasma as a measure of IHg exposure can lead to significant exposure misclassification. THg in urine is a suitable proxy for IHg exposure.
汞（Hg）暴露生物标志物常被用于评估普通人群各群体的暴露情况和风险。我们评估了最常用的生物标志物及其所基于的生理学原理，以探讨个体间差异及其在暴露评估中的适用性。
测定了瑞典男性和女性全血、红细胞、血浆、头发和尿液中总汞（THg）、无机汞（IHg）和有机汞（OHg，假定为甲基汞；MeHg）的浓度。开发了一种用于汞分析的自动多次进样冷蒸气原子荧光分光光度分析系统，该系统具有高灵敏度、准确性和精密度。探讨了不同汞形态在不同生物介质中的分布情况。
红细胞中约90%的汞以MeHg形式存在，个体间差异较小，红细胞中发现的部分IHg可归因于甲基汞的去甲基化。血浆中的THg与IHg和MeHg均相关，红细胞与血浆之间的分布存在较大个体间差异。头发中的THg反映了所有暴露水平下的MeHg暴露，而非IHg暴露。头发中少量的IHg很可能源自甲基汞的去甲基化。血发比的个体间差异非常大。随着血液中OHg含量的增加，这种变异性似乎会降低，这很可能是由于鱼类消费更为频繁，从而使血液浓度接近稳态。尿液中的THg反映了IHg暴露，即使在极低的IHg暴露水平下也是如此。
根据IHg暴露程度，使用全血中THg浓度作为MeHg暴露的替代指标会导致对MeHg暴露的高估，因此需要对汞形态进行分析。红细胞和头发中的THg是MeHg暴露的合适替代指标。使用血浆中THg浓度作为IHg暴露的衡量指标可能会导致显著的暴露误分类。尿液中的THg是IHg暴露的合适替代指标。
