Pollution research on dated sediment cores from Lake Constance

The vertical distribution of eight heavy metals (Hg, Cu, Zn, Cr, CO, Ni, Pb, Cd) and nitrogen and phosphorus in dated sediments of four sedimentary profiles from the central part of Lake Constance was examined. From 1900 to about 1960-1970, a general increase of all heavy metals was observcd. After this time, the concentrations of most of the metals decreased. As compared with pre-1900 "natural" metal concentrations, Cd and Pb have been enriched the strongest (enrichment factors 4.0 and 3.8 resp.), whereas Ni and CO exhibit least civilizational influences (enrichment factors 1.5 and 1.9 resp.). Cu, Cr, Zn and Hg were enriched by a factor between 2-3. Elements which were not influenced by anthropogenic processes - such as K and Li - remained unaffected over the whole vertical sequence. Polycyclic aromatic hydrocarbons (PAH) which were also studied in the same sediment material by Grimmer and Bohnke show a similar pattern. Within a sedimentary profile the concentration ratio benzo (a) pyrene : cadmium remained about constant. Combustion of coal is believed to be the common source of both heavy metals and PAH and seems to be responsible for the general distribution pattern of both groups of pollutants. In addition, local sources - both domestic and industrial - are assumed to have delivered additional heavy metal pollution. […]

对康斯坦茨湖中部四个沉积剖面的年代沉积物中八种重金属（Hg、Cu、Zn、Cr、CO、Ni、Pb、Cd）以及氮和磷的垂直分布进行了考察。从1900年至约1960年至1970年，所有重金属的浓度普遍上升。此后，大多数金属的浓度均有所下降。与1900年以前的“自然”金属浓度相比，Cd和Pb的富集程度最高（富集因子分别为4.0和3.8），而Ni和CO的文明影响最小（富集因子分别为1.5和1.9）。Cu、Cr、Zn和Hg的富集因子介于2至3之间。未受人为过程影响的元素，如K和Li，在整个垂直序列中保持未变。同样由Grimmer和Bohnke在相同沉积物材料中研究的多环芳烃（PAH）也显示出相似的分布模式。在沉积剖面内，苯并(a)芘与镉的浓度比大致保持恒定。煤炭燃烧被认为是重金属和多环芳烃的共同来源，并且似乎负责了这两组污染物的总体分布模式。此外，假定本地来源——包括家庭和工业——也带来了额外的重金属污染。