来源：北部湾海洋环境与灾害重点实验室    编辑：周姣娣    作者：蒙柳清

近日，我实验室Solomon Felix Dan博士在国际知名期刊《Journal of Hazardous Materials》（TOP，影响因子IF=14.224）上发表了题为“Contamination and ecological risk assessment of heavy metals, and relationship with organic matter sources in surface sediments of the Cross River Estuary and nearshore areas”的研究论文。

第一作者：Solomon Felix Dan

通讯作者：Solomon Felix Dan

DOI：https://doi.org/10.1016/j.jhazmat.2022.129531

本文通过对西非尼日利亚东南部退化的红树林生态系统(典型C3植物)的过江河口区及周边近岸表层沉积物中Zn、Pb、Cu和Cd等重金属元素的化学形态特征研究，以评估其表层沉积物中重金属的污染状况和生态风险，以及有机质(OM)来源对重金属来源的制约作用。

污染因子(CF)和地累积指数(Igeo)表明，Cd和Zn是污染最严重的重金属。在非残留组分中较高比例的Zn(63.78%)、Pb(64.48%)、Cd(76.72%)和相当数量的Cu(48.57%)表明，这些重金属具有生物有效性。基于生态风险(Er)和风险评估代码(RAC)表明，Cd具有中高生态风险和生物利用性风险。重金属与细粒径沉积物呈显著正相关，沉积的OM来自于陆生的C3来源。重金属在可氧化组分中所占比例较高(~33-50%)，表明邻近退化红树林生态系统的有机质和富含重金属细粒沉积物的侵蚀冲蚀对该研究区域表层沉积物中重金属含量增加贡献显著。

Fig. 1. Map of the study area showing the surface sediment sampling locations (blue dots) in the Cross River Estuary and nearshore area. The green patches represent some of the adjoining mangrove vegetation, while the red boxes are the mangrove sediments collection sites.

Fig. 2. Spatial distributions of (a) organic carbon (OC), (b) total nitrogen (TN), (c) molar ratio of organic carbon to total nitrogen (OC/TN), and (d) stable isotopic values of organic carbon (δ13C) in surface sediments during the month (August) with the highest rain in 2017.

Fig. 3. Chemical partitioning of (a) zinc (Zn), (b) lead (Pb), (c) copper (Cu), (d) cadmium (Cd), and (e) ecological risk (Er) and (f) risk assessment code (RAC) of heavy metals in surface sediments during the month (August) with the highest rain in 2017. The abbreviations Med and Con in 8c represent medium risk and considerable risk, respectively.

Fig. 4. Pearson correlation results (p < 0.05) of the studied parameters in surface sediments during the month (August) with the highest rain in 2017. Significant correlation increases with colour depth. The cross-marked param-eters are those with insignificant relationships.

本研究由广西科技人才专项基金(No. AD21220148)，北部湾大学科研启动基金(No. 2020KYQD01)共同资助。