Nonylphenol ethoxylates were used as emulsifiers, dispersive agents, surfactants and/or wetting agents and are the primary source of inputs to the sea of NP and short chained NPEs. The main users of NPEs were cleaning sectors, but they were also used in emulsion polymerisation and textiles. Estimated use in Western Europe in 1997 was 76.600 tonnes. In Europe their domestic use has been phased out since 1995, their industrial use since 2000. NP can enter the marine environment mainly through waste water from industrial activities, which produce or use NPEs (or NP), and through municipal waste waters.
NP and short-chained NPEs are toxic to aquatic organisms. NP concentrations of 10µg/l can have effect on the reproduction of fish and concentrations of 100 µg/l are lethal. In mammals and fishes they are also shown to cause endocrine disruptive effects as they appear to feminize juvenile males by acting like oestrogens.
Concentrations between 0.2 and 12 μg/l are current in UK rivers and the Belgian Scheldt estuary. Concentrations up to 180 μg/l have been measured rivers receiving lots of sewage treatment works effluents. In the liver of fresh water fish in Switzerland NP concentrations have been as high as 1 mg/kg dry weight. Concentrations have been decreasing in the past 20 years as a result from reduced use of NPEs.
Environmental standards and legislation