To assess the short-term trend of pollution by hexachlorobenzene (HCB), chlorophenols, and polychlorinated biphenyls (PCB) emitted to a marine environment, existing and former loads were estimated based on pollutant concentrations in water, blue mussels, and sediment, using partitioning calculations. The study included chemical analyses of organochlorines in sediment samples, caged mussels, and semipermeable membrane devices (SPMD) incubated in the water column and in the outflow from an adjacent plant in order to find out whether the high pollutant concentrations found in the superficial sediment corresponded to former or existing discharges. A comparison was made of hypothetical water concentrations calculated from values determined in SPMDs, mussels, and sediment, assuming equilibrium in the distribution of the pollutants between mussels and water or sediment and water. Sediment-derived water concentrations of HCB in the vicinity of the outlet were much higher than the water concentrations calculated from SPMDs or mussels, indicating that the discharges of HCB from a local source were strongly reduced during the past decade. It is concluded that partitioning calculations applied on analytical data from mussels and superficial sediment, when combined with SPMD data, make possible the detection of short-term changes of environmental loads of hydrophobic pollutants.
During January 1995, a severe flooding event in central
and western Europe caused a significant outflow of
contaminated freshwater into the Northern Sea and to
Skagerrak. This water reached the Swedish west coast
in mid-March. During this time, SPMD (semipermeable
membrane device) sampling was performed directly in the
plume. Depending on the salinity, this contaminated
water was found at a depth of 22−25 m in Skagerrak.
Two SPMD sampling sites were placed in this area at a
depth of 24 m, and the SPMDs were changed every 12−16 days during the 12-week study. In the meantime, water
temperature increased from 4 to 8 °C at the 24 m depth.
PCBs, DDTs, chlordane, hexachlorobenzene, α-HCH, γ-HCH
(lindane), dieldrin, and other organochlorine compounds
were detected in the SPMD samples. A time trend with
elevated concentrations during the floodwater arrival, followed
by decreasing concentrations, could be seen for most of
the compounds studied. The highest levels of organochlorine
compounds were found for PCBs and DDTs. The amounts
found in the truly dissolved aqueous phase were
respectively 4 and 2 times higher during mid-March 1995
when compared to an apparent baseline level measured during
April and May. By using earlier reported relationships
between water concentration and sampling rates, a truly
dissolved concentration was calculated for each compound.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.