title: Radium isotope ((223)Ra, (224)Ra, (226)Ra and (228)Ra) distribution near Brazil's largest port, Paranaguá Bay, Brazil.
abstract: This work investigates the (223)Ra, (224)Ra, (226)Ra and (228)Ra isotope distribution in river, estuarine waters and sediments of the Paranaguá Estuarine Complex (PEC). The stratification of the Ra isotopes along water columns indicate differing natural sources. In sediments, the radium isotope activities was inversely proportional to the particle size. The highest concentrations of (223)Ra, (224)Ra, (226)Ra and (228)Ra in the water column were found in the bottom more saline waters and towards the inner of the estuary. These relatively high concentrations towards the bottom of the estuary may be attributed to the influence of tidally driven groundwater source and desorption from particles at the maximum turbidity zone. The apparent river water ages from the radium isotope ratios, (223)Ra/(224)Ra and (223)Ra/(228)Ra, indicate that the principal rivers that flow into the estuary have residence times from between 6 and 11days.
authors.affiliation: Centro de Estudos do Mar da Universidade Federal do Paraná, - Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil.
authors.forename: Thais H
authors.initials: TH
authors.lastname: Dias
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares (IPEN), - Av. Prof. Lineu Prestes, 2242, 05508-900 São Paulo, SP, Brazil.
authors.forename: Joselene
authors.initials: J
authors.lastname: de Oliveira
authors.affiliation: National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 4321, Coffs Harbour, 2450 NSW, Australia. Electronic address: christian.sanders@scu.edu.au.
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Sanders
authors.affiliation: Instituto de Radioproteção e Dosimetria (IRD), - Av. Salvador Allende-Jacarepaguá, 22780-160 Rio de Janeiro, RJ, Brazil.
authors.forename: Franciane
authors.initials: F
authors.lastname: Carvalho
authors.affiliation: National Marine Science Centre, School of Environment, Science and Engineering, Southern Cross University, PO Box 4321, Coffs Harbour, 2450 NSW, Australia.
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Sanders
authors.affiliation: Centro de Estudos do Mar da Universidade Federal do Paraná, - Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil.
authors.forename: Eunice C
authors.initials: EC
authors.lastname: Machado
authors.affiliation: Centro de Estudos do Mar da Universidade Federal do Paraná, - Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil.
authors.forename: Fabian
authors.initials: F
authors.lastname: Sá
mesh_terms: D061006:Bays; D001938:Brazil; D004784:Environmental Monitoring / Q000379:methods; D063366:Estuaries; D005618:Fresh Water; D019015:Geologic Sediments / Q000032:analysis; D060587:Groundwater; D011883:Radium / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D013910:Thorium / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D014875:Water Pollutants, Radioactive; C026062:thorium X; D013910:Thorium; D011883:Radium
keywords: Estuary; Mangrove; Radionuclide tracers; Radium; River; Surface sediment