Crystal structure of lutetium disilicate, Lu2Si2O7

Lu2O7Si2, monoclinic, C12/m1 (No. 12), a 6.762(2) Angstrom, b = 8.835(3) Angstrom, c = 4.711(2) Angstrom, beta = 101.99(4)degrees, V = 275.3 Angstrom(3), Z = 2, R-gt(F) = 0.019, wR(ref)(F-2) = 0.045, T = 293 K

Concentrations of As, Cd, Cr, Ni, and Pb in the echinoid Paracentrotus lividus on the coast of Civitavecchia, northern Tyrrhenian Sea, Italy

This is the accepted manuscript of the paper " Concentrations of As, Cd, Cr, Ni, and Pb in the echinoid Paracentrotus lividus on the coast of Civitavecchia, northern Tyrrhenian Sea, Italy", published as final paper in "Regional Studies in Marine Science 1 (2015) 7–17" Scanu S, Soetebier S, Piazzolla D, Tiralongo F, Mancini E, Romano N, Marcelli M (2015). Concentrations of As, Cd, Cr, Ni, and Pb in the echinoid Paracentrotus lividus on the coast of Civitavecchia, northern Tyrrhenian Sea, Italy. Regional Studies in Marine Science 1 7–17. DOI: 10.1016/j.rsma.2015.02.001. This work assessed the levels of As, Cd, Cr, Ni, and Pb in soft tissues (gonads and gut) of specimens of Paracentrotus lividus (Lamarck, 1816) collected from the coast of Civitavecchia, in the northern Tyrrhenian Sea. The average levels, in order of concentration, were 14.64 mg/kg As, 3.58 mg/kg Cr, 1.18 mg/kg Pb, 1.15 mg/kg Ni, and 0.07 mg/kg Cd. Dry weight concentrations described bioaccumulation of As and Cr, and, to a lesser extent, Ni and Pb. A hotspot of As at the station near the delta of Marangone stream reflected the effect of mine waste deposits of galena, pyrite, and marcasite in this basin. The As concentration in the northern part of the study area increased closer to the Mignone delta, and according to the prevailing winds, this could reflect enrichment from the combustion of coal at the Torrevaldaliga power plant. Comparing data with the literature, As in marine sediments show a ratio of 0.7 in the tissues of P. lividus from the Civitavecchia area. These results were also compared to those found in P. lividus in an environmental biomonitoring program currently ongoing to control the emissions from the coal-fired power plant in Torrevaldaliga Nord, highlighting a substantial quantitative correspondence. In view of the presence of various industrial activities in the study area that can influence the enrichment of these elements, this work emphasizes the need for performing further studies aimed at assessing the actual contribution of anthropogenic activities even when the background concentrations in marine sediments and marine organisms are high, because burning coal is considered the major anthropogenic source of many trace elements especially As