文摘
Estrogenic substances discharged from wastewatertreatment plants have been detected in surface sedimentsof receiving waters, but little is known of their verticalmigration through buried sediments and their potential tocontaminate subsurface waters. The vertical profiles ofestrogenic chemicals were investigated in sediment coresat an alluvial freshwater site (Ditchling) and a clay-richestuarine site (Lewes), both of which are downstream ofwastewater discharges into the River Ouse (Sussex, U.K.).Estrone (E1) was the predominant estrogen detected insurface and buried sediments at both sites and was detectedin undisturbed clay sediments >120 years old. Profilesof E1 at Ditchling were characterized by a prominentsubsurface peak of E1 at the alluvium/clay interface (-15cm) at a concentration (28.8 ± 6.0 ng/g of dry wt) thatwas 9-fold higher than in the surface sediment. In contrast,a steady downcore decline in E1 concentrations wasobserved in the clay-rich Lewes core. This work providesthe first in situ evidence of estrogen migration throughriver bed sediments and reveals that movement of estrogensthrough unconsolidated sediment can result in penetrationto the underlying substrata and therefore the potentialfor groundwater contamination.