Abstract：
Human biomonitoring of toxic trace elements is of critical importance for public health protection. The current study aims to assess the levels of selected trace metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn) into paired human nail and hair samples (n = 180 each) from different altitudinal setting along the Indus River, and which were measured by using inductively coupled plasma mass spectrometry (ICP-MS). The human samples (hair and nail) were collected from four different ecological zones of Pakistan which include frozen mountain zone (FMZ), wet mountain zone (WMZ), riverine delta zone (RDZ), and low-lying southern areas (LLZ). Our results showed the following occurrence trends into studied hair samples: higher values (ppm) of Zn (281), Co (0.136), and Mn (5.65) at FMZ; Cr (1.37), Mn (7.83), and Ni (1.22) at WMZ; Co (0.15), Mn (11.89), and Ni (0.99) at RDZ; and Mn (8.99) and Ni (0.90) at LLZ. While in the case of nails, the levels (ppm) of Mn (9.91) at FMZ and Mn (9.38, 24.1, and 12.5), Cr (1.84, 3.87, and 2.33), and Ni (10.69, 8.89, and 12.6) at WMZ, RDZ and LLZ, respectively, showed higher concentration. In general, among the studied trace elements, Mn and Ni in hair/nail samples were consistently higher and exceeded the WHO threshold/published reference values in most of the studied samples (> 50-60%) throughout the Indus basin. Similarly, hair/nail Pb values were also higher in few cases (2-10%) at all studied zones and exceeded the WHO threshold/published reference values. Our area-wise comparisons of studied metals exhibited altitudinal trends for Cd, Cr, Zn, and Mn (p < 0.05), and surprisingly, the values were increasing from south to north (at higher altitudes) and indicative of geogenic sources of the studied toxic elements, except Mn, which was higher at lower floodplain areas. Estimated daily intake (EDI) values showed that food and drinking water had the highest contribution towards Zn, Cu, Mn, and Ni and accumulation at all studied zones. Whereas, dust also acts as the main exposure route for Mn, Co, Cr, and Cd followed by the food, and water.
摘要：
人体有毒微量元素的生物监测对于公共卫生保护至关重要。当前的研究旨在评估选定的痕量金属(Cd，Co,Cr,Cu,Mn,Ni,Pb,和Zn）成对的人类指甲和头发样本（每个n=180）来自印度河沿岸的不同海拔环境，并通过使用电感耦合等离子体质谱法(ICP-MS)测量。人类样本（头发和指甲）是从巴基斯坦的四个不同生态区收集的，其中包括冰冻山区（FMZ），湿山区（WMZ），河流三角洲(RDZ),和低洼的南部地区（LLZ）。我们的结果显示以下发生趋势到研究的头发样本：较高的值（ppm）的Zn（281），Co（0.136），FMZ的Mn（5.65）；Cr（1.37），Mn(7.83),在WMZ和Ni（1.22）；Co（0.15），锰(11.89)，和Ni(0.99)在RDZ;和Mn(8.99)和Ni(0.90)在LLZ。而在指甲的情况下，FMZ和Mn（9.38、24.1和12.5）的Mn（9.91）水平（ppm），Cr（1.84、3.87和2.33），和Ni（10.69，8.89和12.6）在WMZ，RDZ和LLZ，分别,显示浓度较高。总的来说,在研究的微量元素中，在整个印度河流域的大多数研究样品（>50-60％）中，头发/指甲样品中的Mn和Ni始终较高，并超过WHO阈值/公布的参考值。同样，在所有研究区域中，头发/指甲Pb值在少数情况下（2-10％）也较高，并且超过了WHO阈值/公布的参考值。我们对所研究金属的逐区比较显示出Cd的海拔趋势，Cr,Zn,和锰(p<0.05)，令人惊讶的是，这些值从南到北（在较高的海拔）增加，表明所研究的有毒元素的地质来源，除了锰，在较低的洪泛区较高。估计的每日摄入量（EDI）值表明，食物和饮用水对锌的贡献最大，Cu,Mn,所有研究区的Ni和积累。然而,粉尘也是锰的主要暴露途径，Co,Cr,然后是食物，和水。
