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(M/EH104) Nonylphenol and nonylphenol ethoxylates in Swiss rivers: impact of risk reduction measures and seasonal effects. Molnar, E.1, Ahel, M. 1, Schaffner, C. 1, Schonenberger, U. 1, Giger, W. 1, 1 ABSTRACT- Between 1982 and 1984 4-nonylphenol (NP), 4-nonylphenolmonoethoxylate (NP1EO) and 4-nonyl-phenol-diethoxylate (NP2EO) were thoroughly investigated in sewage effluents, sewage sludges and in ambient waters in Switzerland. Based on the results of these exposure measurements, the use of 4-nonylphenol polyethoxylates (NPnEO) as nonionic surfactants in laundry detergents was banned in 1986 by the Swiss ordinance for environmental pollutants. The detergent manufacturing company phased out the addition of NPnEO surfactants to household surface cleaners, but still included them in industrial cleaners and in some other industrial applications. It is estimated that in the year 2000 still about 500 tons of NPnEO are applied annually in Switzerland for industrial and institutional purposes. This poster reports on a study in Swiss rivers aiming at investigating the residual concentrations occurring after the impact of the above mentioned risk reduction measures. Composite flow proportional samples werde collected at several Swiss rivers. Analytical methods based on liquid chromatography combined with fluorometric detection provided quantitative determinations of the lipophilic metabolites NP, NP1O and NP2EO. The levels in the Glatt River are compared to the levels, which have been found in 1982 to 1984. The results clearly show the impact of risk reduction measures. In addition, several rivers showed seasonal effects characterized by higher levels of the lipophilic metabolites during the winter season. In the Glatt River the winter maxima for NP concentrations were around 0.45 microgram per liter exceeding the currently proposed European PNEC value of 0.33 microgram per liter water. The winter values in 1983/4 had ranged from 7 to 13 microgram NP per liter. Thus, the maximum NP concentration in the Glatt River decreased by a factor of approximately 20. Key words: nonylphenol , degradation products, nonylphenol ethoxylates, risk reduction |
