Browsing by Author "Soto, Manu"
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- Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soilsPublication . Amaral, André; Soto, Manu; Cunha, Regina Tristão da; Marigómez, Ionan; Rodrigues, ArmindoWhether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former.
- Freshwater molluscs from volcanic areas as model organisms to assess adaptation to metal chronic pollutionPublication . Zaldibar, Beñat; Rodrigues, Armindo; Lopes, Marco; Amaral, André; Marigómez, Ionan; Soto, ManuCellular biomarkers of exposure and biological effects were measured in digestive gland of snails (Physa acuta) sampled in sites with 12 andwithout active volcanismin SãoMiguel Island (Azores).Metal content in digestive cell lysosomeswas determined by image analysis 13 after autometallography (AMG) as volume density of autometallographed black silver deposits (VvBSD). Lysosomal structural changes 14 (lysosomal volume, surface and numerical densities – VvLYS, SvLYS and NvLYS−, and surface-to-volume ratio – S/VLYS−) were 15 quantified by image analysis, after demonstration of β-glucuronidase activity, on digestive gland cryotome sections. Additional chemical 16 analyses (atomic absorption spectrophotometry) were done in the digestive gland of snails. The highestmetal concentrations were found 17 in snails from the active volcanic site, which agreed with high intralysomal VvBSD. Digestive cell lysosomes in snails inhabiting sites 18 with active volcanismresembled a typical stress situation (enlarged and less numerous lysosomes). In conclusion, the biomarkers used in 19 this work can be applied to detect changes in metal bioavailability due to chronic exposure to metals (volcanism), in combination with 20 chemical analyses.