title: Chemical element accumulation in tree bark grown in volcanic soils of Cape Verde-a first biomonitoring of Fogo Island.
abstract: Barks from Prosopis juliflora (acacia) were collected in 12 sites of different geological contexts over the volcanic Fogo Island (Cape Verde). Elemental contents of Ba, Br, Co, Cr, Fe, K, Na, Zn and some rare earth elements (REE)-La, Ce, Sm, Eu, Tb, Yb, and Lu, were obtained for biological samples and topsoils by using k0-standardized and comparative method of instrumental neutron activation analysis (INAA), aiming the evaluation of chemical elements uptake by acacia bark. This first biomonitoring study of Fogo Island showed that, in general, significant accumulations of trace elements present in high amounts in these soils occur. This can be partially explained by the semi-arid climate with a consequent bioavailability of chemical elements when rain drops fall in this non-polluted environment. REE enrichment factors (EFs) increase with the decrease of ionic radius. Heavy REE (HREE) are significantly enriched in bark, which agrees with their release after the primary minerals breakdown and the formation of more soluble compounds than the other REE, and uptake by plants. Among the potential harmful chemical elements, Cr appears to be partially retained in nanoparticles of iron oxides. The high EFs found in tree barks of Fogo Island are certainly of geogenic origin rather than anthropogenic input since industry and the use of fertilizers is scarce.
authors.affiliation: Centro de Ciências e Tecnologias Nucleares (C2TN), IST, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066, Bobadela, Portugal. rmarques@ctn.ist.utl.pt.|GeoBioTec, Universidade de Aveiro, Aveiro, 3810-193, Portugal. rmarques@ctn.ist.utl.pt.
authors.forename: Rosa
authors.initials: R
authors.lastname: Marques
authors.affiliation: Centro de Ciências e Tecnologias Nucleares (C2TN), IST, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066, Bobadela, Portugal.|GeoBioTec, Universidade de Aveiro, Aveiro, 3810-193, Portugal.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Prudêncio
authors.affiliation: Centro de Ciências e Tecnologias Nucleares (C2TN), IST, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066, Bobadela, Portugal.
authors.forename: Maria do Carmo
authors.initials: MDC
authors.lastname: Freitas
authors.affiliation: Centro de Ciências e Tecnologias Nucleares (C2TN), IST, Universidade de Lisboa, Estrada Nacional 10 (km 139.7), 2695-066, Bobadela, Portugal.|GeoBioTec, Universidade de Aveiro, Aveiro, 3810-193, Portugal.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Dias
authors.affiliation: GeoBioTec, Universidade de Aveiro, Aveiro, 3810-193, Portugal.|Departamento de Geociências, Universidade de Aveiro, Aveiro, 3810-193, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Rocha
mesh_terms: D000045:Acacia / Q000737:chemistry*; D000393:Air Pollutants / Q000032:analysis*; D055726:Cabo Verde; D004784:Environmental Monitoring / Q000379:methods*; D062312:Islands; D024301:Plant Bark / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D012987:Soil
keywords: Bark; Biomonitoring; Fogo Island; INAA; REE; Trace elements; Volcanic soils