Accumulation profiles of parabens and their metabolites in fish, black bear, and birds, including bald eagles and albatrosses

Abstract

Although several studies have reported the ubiquitous occurrence of parabens in human specimens and the environment, little is known about the accumulation of these estrogenic chemicals in fish and birds. In this study, accumulation profiles of six parabens and their metabolites were determined in 254 tissue (including liver, kidney, egg, and plasma) samples from 12 species of fish and seven species of birds collected from inland, coastal, and remote aquatic ecosystems. In addition, liver and kidney tissues from black bears were analyzed. Methyl paraben (MeP) was found in a majority of the tissues, with the highest concentration (796ng/g (wet weight [wet wt])) found in the liver of a bald eagle from Michigan. 4-Hydroxy benzoate (HB) was the major metabolite, found in 91% of the tissue samples analyzed at concentrations as high as 68,600ng/g, wet wt, which was found in the liver of a white-tailed sea eagle from the Baltic Sea coast. The accumulation pattern of MeP and 4-HB varied, depending on the species. The mean concentrations of MeP measured in fishes from Michigan, New York, and Florida waters were <2.01 (fillet), 152 (liver), and 32.0 (liver) ng/g, wet wt, respectively, and the corresponding 4-HB concentrations were 39.5, 10,500, and 642ng/g, wet wt. The mean hepatic and renal concentrations of 4-HB in black bears were 1,720 and 1,330ng/g, wet wt, respectively. The concentrations of MeP and 4-HB were significantly positively correlated with each other in various tissues and species, which suggested a common source of exposure to these compounds in fish and birds. Trace concentrations of MeP and 4-HB also were found in the tissues of albatrosses from Midway Atoll, Northwestern Pacific Ocean, which suggested widespread distribution of these compounds in the marine environment.