包括Al在内的13个元素,Ag,As,Co,Cu,Cd,Cr,Fe,Mn,Ni,Se,Zn,在苏必利尔湖的107个地表沉积物样品和8个岩心的175个片段中测量了铅和铅,密歇根州,和休伦,使用电感耦合等离子体质谱(ICP-MS)。Ponar抓斗中的浓度在金属和位置之间差异很大,范围从苏必利尔湖的铁最高中位数(42,000mg/kg)到休伦湖的银最低中位数(0.05mg/kg)。取芯地点的库存范围为7×106mg/m2的Fe至3mg/m2的Ag。背景浓度是从更深的岩心段估计的,以Fe或Al为参考元素计算富集系数(EF)。结果表明,Al,Fe,Co,Cr,锰没有富集,Ag,Cu,镍的含量高于预期的天然来源,而Pb,Cd,Se,Zn,在欧洲定居该地区后,大多数地点都得到了丰富。密歇根湖的大多数金属的EF高于其他湖泊。然而,采样点之间的EF比较揭示了这种方法评估人为干扰的内在问题。初步风险评估,通过计算风险商进行,揭示了每个湖泊中某些金属的环境风险;然而,应谨慎解释结果,因为所使用的方法被认为是保守的.
Thirteen elements including Al, Ag, As, Co, Cu, Cd, Cr, Fe, Mn, Ni, Se, Zn, and Pb were measured in 107 surface grab
sediment samples and 175 segments of eight cores from Lakes Superior, Michigan, and Huron, using inductively coupled plasma mass spectrometry (ICP-MS). Concentrations in Ponar grabs vary considerably among metals and among locations, ranging from the highest median for Fe in Lake Superior (42,000 mg/kg) to the lowest median for Ag in the main Lake Huron (0.05 mg/kg). The inventory at coring sites ranged from 7 × 106 mg/m2 of Fe to 3 mg/m2 of Ag. The background concentrations were estimated from deeper core segments, and enrichment factors (EFs) were calculated with Fe or Al as the reference element. The results show that Al, Fe, Co, Cr, and Mn did not enrich, Ag, Cu, and Ni were present higher than expected from natural sources alone, while Pb, Cd, Se, Zn, and As have been enriched at most sites after European settlement in the region. EFs of most metals are higher for Lake Michigan than the other lakes. However, EF comparison among sampling sites revealed intrinsic problems of this approach for the assessment of human interference. Preliminary risk assessment, conducted by calculating risk quotients, revealed environmental risks of some metals in each lake; however, the results should be interpreted with caution because the approach used is considered to be conservative.