PARENT SESSION
3H Analysis, fate, and effects of surfactants in the environment
9:00 AM to 7:00 PM, Monday, 07 May 2001

(M/EH102) Alkylphenol ethoxylates and their degradation products in sediments and particulate matter from Dutch waterways.

de Voogt, Pim¹, Kwast, Onno¹, Jonkers, Niels¹, ¹

ABSTRACT- The Dutch national Investigation into the occurrence and effects of estrogenic compounds in the aquatic environment involves a major baseline survey on known or suspected xeno-oestrogens in the Dutch aquatic environment. At our department the analysis of alkylphenols (AP) and their ethoxylates (APE) has been carried out for this project. Sediments and particulate matter from waterways contain nonylphenol (up to 2.8 mg/kg) and its ethoxylates (up to 17 mg/kg) whereas octylphenol or its ethoxylates were generally absent and only found in the Rhine/Meuse estuary and in the Noordzeekanaal. Particulate matter generally contained higher levels than sediments. NPE and NP were found in most of the particulate matter and sediment samples at levels above the limit of determination, whereas levels of OPE and OP were below limits of detection. Sediments appear to have relatively enriched levels of NP. The ratio of NP to NPE is much higher than in e.g. samples of particulate matter, and this ratio seems to increase from water < particulate matter < marine sediment < freshwater sediment. In 10 out of 12 freshwater sediments, and 5 out of 11 marine sediments the NP/NPE ratio is more than 1. In particulate matter, this value is observed in only 7 out of 50 samples. These findings are discussed in relation to the sediment and suspended matter characteristics. Sampling stations in this survey allow us to follow (by comparing riverine data) the fate of NPE and NP from their entrance into The Netherlands until when the estuaries are reached. The plots show that levels of NPE and NP in sediments and particulate matter are relatively high in rivers Meuse and Scheldt where these enter the territory of The Netherlands, compared to the Rhine river. However, as the Meuse and Scheldt discharge into relatively large estuaries, the concentrations appear to become significantly 'diluted', even if obvious local discharges are present. On the contrary, the levels in sediments and particulate matter increase in the Rhine from Lobith at the German border to the estuary. The significance of the corresponding AP/APE loadings for the receiving coastal environment will be discussed.

Key words: alkylphenol ethoxylates, sediment, surfactant