Tissue-Specific Toxicokinetics of Aqueous Radium-226 in an Estuarine Mussel, Geukensia demissa

Abstract

Radiological contamination of coastal habitats poses potential risk for native fauna, but the bioavailability of aqueous radium (Ra) and other dissolved metals to marine bivalves remains unclear. This study was the first to examine the tissue-specific disposition of aqueous 226 Ra in a coastal mussel, specifically the Atlantic ribbed mussel Geukensia demissa. Most organ groups reached steady-state concentrations within 7 days during experimental exposure, with an average uptake rate constant of 0.0013 mL g −1 d −1 . When moved to Ra-free synthetic seawater, mussels rapidly eliminated aqueous 226 Ra (average elimination rate constant 1.56 d −1 ). The biological half-life for aqueous 226 Ra ranged from 8.9 h for the gills and labial palps to 15.4 h for the muscle. Although previous field studies have demonstrated notable 226 Ra accumulation in the soft tissues of marine mussels and that, for freshwater mussels, tissue-incorporated 226 Ra derives primarily from the aqueous phase, our tissue-specific bioconcentration factors (BCFs) were on the order of (8.3 ± 1.5) × 10 −4 indicating low accumulation potential of aqueous 226 Ra in estuarine mussels. This suggests marine and estuarine mussels obtain 226 Ra from an alternate route, such as particulate-sorbed Ra ingested during filter-feeding or from a contaminated food source.

Stochastic Dynamic Mass Spectrometric Quantitative and Structural Analyses of Pharmaceutics and Biocides in Biota and Sewage Sludge

“…The biomonitoring of pollutants via mussels allows us (a) to determine the concentration levels of pollutants in feral organisms; (b) to examine the spatial (geographic) distribution of pollution, if any; and (c) to study the temporal distribution and variation of pollution toward distinct seasons. The toxicokinetics examines four major processes of biological objects such as mussels, involving (a) the adsorption of pollutants; (b) their distribution, (c) metabolism, and (d) excretion [ 44 ]. The rates of the processes determine the contaminant’s bioavailability .…”