Polycyclic aromatic hydrocarbons (PAH) in seawater around England and Wales

Surface seawater samples collected during the period 1993–1995 from 177 stations around England and Wales have been analysed for 15 individual parent PAH compounds, using high-performance liquid chromatography with fluorescence detection. The sampling sites included 50 of the stations designated under the UK National Monitoring Programme, and comprised estuarine, coastal and offshore locations. PAH concentrations at offshore sites were generally low or undetectable. Higher concentrations were found in many coastal and estuarine samples, with ∑PAH concentrations ranging from none detected to 10.7 μgl−1, almost three orders of magnitude greater than the highest concentration recorded for offshore waters. Particularly high concentrations of 2- and 3-ring PAH were detected close to a steel manufacturing plant on the River Tees (N-E England), predominantly in the dissolved phase. Only at this one site were the PAH concentrations sufficiently high to pose a risk of immediate mortality in exposed organisms, but about 15% of the samples analysed in this study came from waters (almost all in industrialized estuaries) that may have the potential to affect the long-term wellbeing of a range of aquatic organisms.