Heavy metals and carbon isotope concentrations in recent Baltic Sea sediments

The sedimentation rate was determined from radiocarbon dates to be 1.4 mm/yr. The 'recent age' of the sediment was about 850 yr.

Within the upper 20 cm of sediment, certain heavy metals became increasingly enriched towards the surface; Cd, Pb, Zn and Cu increased 7-, 4-, 3- and 2-fold, respectively, whereas Fe, Mn, Ni and Co remained unchanged. Simultaneously, the radiocarbon content decreased by about 14 per cent. The enrichment in heavy metals as well as the decrease in the 14C-concentration during the last 130 ± 30yr parallels industrial growth as reflected in European fossil fuel consumption within that same period of time.