CESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra, 1317, 4585-116 Gandra, PRD, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Edifício do Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4050-208 Matosinhos, Portugal.
CESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra, 1317, 4585-116 Gandra, PRD, Portugal; LAQV / REQUIMTE, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
Sci Total Environ. 2018 Oct 15;639:1381-1393. doi: 10.1016/j.scitotenv.2018.05.234. Epub 2018 May 26.
The present study evaluated the content and distribution of several trace elements (Li, Be, Al, V, Cr, Co, Ni, Cu, Zn, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, and U) in the Douro River estuary. For that, three matrices were collected (water, sediments and native local flora) to assess the extent of contamination by these elements in this estuarine ecosystem. Results showed their occurrence in estuarine water and sediments, but significant differences were recorded on the concentration levels and pattern of distribution among both matrices and sampling points. Generally, the levels of trace elements were higher in the sediments than in the respective estuarine water. Nonetheless, no correlation among trace elements was determined between water and sediments, except for Cd. Al was the trace element found at highest concentration at both sediments and water followed by Zn. Pollution indices such as geo-accumulation (I), enrichment factor (EF) and contamination factor (CF) were determined to understand the levels and sources of trace elements pollution. I showed strong contamination by anthropogenic activities for Li, Al, V, Cr, Ni, Cu, Zn, Ba and Pb at all sampling points while EF and CF demonstrated severe enrichment and contamination by Se, Sb and Pb. Levels of trace elements were compared to acceptable values for aquatic organisms and Sediment Quality Guidelines. The concentration of some trace elements, namely Al, Pb and Cu, were higher than those considered acceptable, with potential negative impact on local living organisms. Nevertheless, permissible values for all trace elements are still not available, demonstrating that further studies are needed in order to have a complete assessment of environmental risk. Furthermore, the occurrence and possible accumulation of trace elements by local plant species and macroalgae were investigated as well as their potential use as bioindicators of local pollution and for phytoremediation purposes.
本研究评估了杜罗河河口几种微量元素（Li、Be、Al、V、Cr、Co、Ni、Cu、Zn、Se、Mo、Ag、Cd、Sb、Ba、Tl、Pb 和 U）的含量和分布。为此，收集了三种基质（水、沉积物和当地自然植物），以评估这些元素在该河口生态系统中的污染程度。结果表明，这些元素在河口水中和沉积物中均有存在，但在两种基质和采样点之间，浓度水平和分布模式存在显著差异。一般来说，微量元素在沉积物中的浓度高于相应的河口水中。然而，除了 Cd 之外，在水和沉积物之间没有确定微量元素之间的相关性。Al 是在沉积物和水中均发现浓度最高的微量元素，其次是 Zn。为了了解微量元素污染的水平和来源，确定了地质累积指数（I）、富集因子（EF）和污染因子（CF）等污染指数。I 表明，在所有采样点，由于人为活动，Li、Al、V、Cr、Ni、Cu、Zn、Ba 和 Pb 受到强烈污染，而 EF 和 CF 则表明 Se、Sb 和 Pb 受到严重富集和污染。将微量元素的水平与水生生物和沉积物质量准则的可接受值进行了比较。一些微量元素，如 Al、Pb 和 Cu 的浓度高于可接受值，对当地生物可能产生负面影响。然而，对于所有微量元素，仍然没有允许值，这表明需要进一步研究，以便对环境风险进行全面评估。此外，还研究了当地植物物种和大型藻类中微量元素的存在和可能积累，以及它们作为当地污染生物指标和植物修复目的的潜在用途。
