| Popis: |
Chlorinated paraffins (CPs) are widely used industrial chemicals e.g., as metal working fluids, rubber additives, flame retardants, etc. These chemicals are multiconstituent mixtures, which are categorized into short-chain (SCCPs), medium-chain (MCCPs), and long-chain mixtures (LCCPs). Only SCCPs have been under regulation as POPs. Spatial and temporal trends of SCCPs, MCCPs, and LCCPs in Swedish marine environment were investigated in the present report. Three sediment cores were collected from the Baltic Sea and from the Kattegatt. CPs and TOC were analyzed in the dated sediment sections and compared with the other three sediment cores collected from the Swedish coastal line in a previous study. Sediments nearby industrial areas showed the highest concentrations of CPs (up to 1400 ng/g d.w.), over 80% of which were MCCPs. The highest concentration of SCCPs (170 ng/g d.w.) was found in the sediments nearby a smelter as well as a recycling facility for electric wastes. Over the past decades, decreasing trends of CPs or relatively consistent levels of MCCPs and LCCPs were found in most sediment cores. However, increasing trends of SCCPs were shown in the sediment cores from the Bothnian Sea and Kattegatt even though the use of SCCPs has been restricted in Sweden and Denmark since 1991. Further studies on source identification are warranted. |
