Estrogenic alkylphenols in fish tissues, sediments, and waters from the UK Tyne and Tees estuaries

Nonylphenols and related compounds are common products of biodegradation of a large group of nonionic surfactants, the nonylphenol polyethoxylates. Many of these compounds are known to be environmentally persistent and to elicit estrogenic response in both mammals and fish. In this study, nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and octylphenol (OP) were found in tissues of mature male flounder, Platichthys flesus(5-55 ng/g NP, 190-940 ng/g NP1EO, wet weight), and in tissues of juvenile flounder (30-180 ng/g NP, wet weight). These fish also showed detectable levels of the yolk protein vitellogenin in their plasma, indicative of estrogenic exposure. The compounds were also found in discharges from a major sewage treatment works (3000 ng/L NP, 45000 ng/L NP1EO) and in sediments from two estuaries in north-east England; the highest levels from the highly industrialized Tees (1600-9050 ng/g NP, 125-3970 ng/g NP1EO, 30-340 ng/g OF, dry weight) and lower levels from the industrialized/urbanised Tyne estuary (30-80 ng/g NP, 160-1400 ng/g NP1EO, 2-20 ng/g OP dry weight). The implications of these findings for fish populations are discussed.