Hossain Mohammad Belal, Sultana Jakia, Jolly Yeasmin N, Nur As-Ad Ujjaman, Sultana Salma, Miazee Rubel, Islam M Saiful, Paray Bilal Ahamad, Arai Takaomi, Yu Jimmy
Department of Fisheries and Marine Science, Noakhali Science and Technology University, Noakhali 3814, Bangladesh; School of Engineering and Built Environment, Griffith University, Brisbane, QLD 4111, Australia.
Department of Fisheries and Marine Science, Noakhali Science and Technology University, Noakhali 3814, Bangladesh.
Mar Pollut Bull. 2023 Sep;194(Pt B):115337. doi: 10.1016/j.marpolbul.2023.115337. Epub 2023 Jul 27.
Functioning of coastal wetland habitats is essential for the ecosystem integrity and sustainability of coastal development that enables human progress along transitional waterways. However, these habitats are continuously being affected by a variety of pollutants including metallic elements. In this study, seasonal variation, pollution status and ecological risks of heavy metals (Cr, Mn, Co, Ni, As, Cu, Zn and Pb) in surface sediment of the several types of coastal wetlands (estuaries, mudflats, sandy beaches, mangroves, and saltmarshes) were detected by using X-ray fluorescence (EDXRF) spectrometry. The results showed that the mean concentration level of metals in the surficial sediment samples followed the order of Cu (84.06 ± 8.60 μg/g) > Zn (51.00 ± 8.97 μg/g) > Mn (38.25 ± 11.34 μg/g) > Cr (3.52 ± 0.91 μg/g) > Pb (0.27 ± 0.13 μg/g) > Co (0.24 ± 0.13 μg/g) > As (0.21 ± 0.12 μg/g) > Ni (0.16 ± 0.08 μg/g). In comparison to the pre-monsoon period, the post-monsoon season had higher concentrations of heavy metals while the overall accumulation level of metals in the wetlands exhibited a pattern of estuarine wetland (28.47 ± 31.35 μg/g) > mangrove (22.23 ± 30.79 μg/g) > mudflat (21.79 ± 29.71 μg/g) > sandy beach (21.47 ± 28.15 μg/g) > saltmarsh (21.28 ± 30.02 μg/g). Although, the pollution assessment indices e.g., contamination factor (CF), degree of contamination (CD), geoaccumulation index (I) and pollution load index (PLI) showed minimal levels of contamination in the studied sites, enrichment factor (EF) suggested greater enrichment of the metals in the pre-monsoon season but with the lowest ecological risk (RI < 40) in both seasons. Cluster analysis, principal component analysis (PCA), and Pearson's correlation were performed to determine the sources of heavy metals in collected samples which specified that Pb, As, Co and Ni predominantly came from natural sources whereas Cu, Mn, Zn and Cr emerged from anthropogenic sources such as industrial effluents, domestic wastewater, fertilizer or pesticide consumption on farmland along the riverbank, vessel emissions, and the confluence of tributary rivers.
沿海湿地栖息地的功能对于生态系统的完整性以及沿海地区发展的可持续性至关重要，沿海地区的发展推动了人类在过渡性水道沿线的进步。然而，这些栖息地正持续受到包括金属元素在内的各种污染物的影响。在本研究中，利用X射线荧光（EDXRF）光谱法检测了几种类型沿海湿地（河口、泥滩、沙滩、红树林和盐沼）表层沉积物中重金属（铬、锰、钴、镍、砷、铜、锌和铅）的季节变化、污染状况和生态风险。结果表明，表层沉积物样本中金属的平均浓度水平顺序为：铜（84.06±8.60μg/g）＞锌（51.00±8.97μg/g）＞锰（38.25±11.34μg/g）＞铬（3.52±0.91μg/g）＞铅（0.27±0.13μg/g）＞钴（0.24±0.13μg/g）＞砷（0.21±0.12μg/g）＞镍（0.16±0.08μg/g）。与季风前时期相比，季风后季节重金属浓度更高，而湿地中金属的总体积累水平呈现出河口湿地（28.47±31.35μg/g）＞红树林（22.23±30.79μg/g）＞泥滩（21.79±29.71μg/g）＞沙滩滩（21.47±28.15μg/g）＞盐沼（21.28±30.02μg/g）的模式。尽管污染评估指数，如污染因子（CF）、污染程度（CD）、地累积指数（I）和污染负荷指数（PLI）显示研究地点的污染水平最低，但富集因子（EF）表明季风前季节金属的富集程度更高，但两个季节的生态风险均最低（RI＜40）。进行了聚类分析、主成分分析（PCA）和皮尔逊相关性分析，以确定采集样本中重金属的来源，结果表明铅、砷、钴和镍主要来自自然源，而铜、锰、锌和铬则来自人为源，如工业废水、生活污水、河岸农田的化肥或农药使用、船舶排放以及支流的汇流处。
