Polycyclic Aromatic Hydrocarbons in Surface Sediments Around England and Wales, and Their Possible Biological Significance

Concentrations of polycyclic aromatic hydrocarbons (PAH) were determined in sediments taken at offshore, coastal and estuarine sites around the UK during the period 1993–1996. In all, 99 samples were taken from 80 locations, including 48 of the stations established under the UK National Monitoring Programme. Fifteen individual parent PAH compounds were determined using a method incorporating an ultrasonication extraction step, followed by on-line clean-up and high performance liquid chromatography (HPLC) with fluorescence detection. The highest concentrations of 4–6-ring PAH were found at a site within Milford Haven, and derive primarily from combustion sources within the estuary. High concentrations of these compounds were also found in the industrialised estuaries of the Rivers Tyne, Wear and Tees (NE England), and these estuaries also yielded the highest concentrations of the low-molecular weight (MW) PAH. An ecotoxicological assessment indicates that the estuaries of the English northeast coast (Tyne, Wear and Tees) and Milford Haven contain PAH-contaminated sediments at some sites which are likely to be acutely toxic to certain sediment dwellers. Furthermore, a wider range of industrialised estuaries appears to contain enough PAH in sediments to cause chronic effects, including the induction of neoplastic liver disease in fish.