title: Bioaccumulation and lack of oxidative stress response in the ragworm H. diversicolor following exposure to 226Ra in sediment.
abstract: The main effluent from oil and gas production, produced water, from some platforms in the North Sea contains elevated concentrations of (226)Ra. The aim of this study was to investigate whether (226)Ra in sediment would accumulate in and affect sediment-dwelling organisms. In addition, we wanted to determine if the bioavailability would be modulated by the presence of a scale inhibitor which is used during oil and gas production. Hediste diversicolor was therefore exposed to different levels of (226)Ra (30-6600 Bq kg(-1)) in combination with scale inhibitor in the sediments in a flow through system. The levels of radioactivity in the exposures were close to levels that can be measured in proximity to oil/gas production facilities. (226)Ra spiked to natural sediment partitioned into pore water and accumulated in the sediment-dwelling polychaete following a four-week exposure period. The results suggest that (226)Ra did not bind strongly to sediment (low sediment:water partitioning coefficient), but it was not shown to bioaccumulate in any great extent (bioaccumulation factors of 0.019-0.022). Exposure of H. diversicolor in sediments with up to 6600 Bq kg(-1)(226)Ra had no measurable effect on the total oxyradical scavenging capacity of the organisms compared to control. So although they accumulated the alpha-emitter, the treatments did not appear to cause oxidative stress in polychaete tissues.
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0324 Oslo, Norway. mgr@niva.no
authors.forename: Merete
authors.initials: M
authors.lastname: Grung
authors.forename: Anders
authors.initials: A
authors.lastname: Ruus
authors.forename: Tor Fredrik
authors.initials: TF
authors.lastname: Holth
authors.forename: Rajdeep Singh
authors.initials: RS
authors.lastname: Sidhu
authors.forename: Dag Øistein
authors.initials: DØ
authors.lastname: Eriksen
authors.forename: Ketil
authors.initials: K
authors.lastname: Hylland