Jahan Sharmin, Jewel Md Abu Sayed, Khatun Bithy, Barman Arun Chandra, Akter Sumaiya, Haque Md Ayenuddin
Department of Fisheries, Faculty of Fisheries, University of Rajshahi, Rajshahi, 6205, Bangladesh.
Department of Oceanography and Blue Economy, Faculty of Fisheries, Habiganj Agricultural University, Habiganj, 3300, Bangladesh.
Heliyon. 2024 Sep 5;10(17):e37496. doi: 10.1016/j.heliyon.2024.e37496. eCollection 2024 Sep 15.
Current state of contamination and subsequent risk of contaminated sediment of a tidal river of Bangladesh was evaluated in the present study. Sediment samples were collected from five locations in the tributary of Bakkhali River estuary during summer (April) and winter (December) season, 2020. Collected samples were processed using standard protocol and the content of heavy metals (Cd, Cr, Cu, Pb and Zn) and metalloid (As), were analyzed by the Flame Atomic Absorption Spectrometer. Sediment contamination was evaluated by pollution load index (PLI), contamination factor (CF), degree of contamination (), potential ecological risk index (PERI), non-carcinogenic and carcinogenic risk (CR) due to the dermal contact of the sediment. Multivariate statistical analysis such as principal component analysis (PCA) and cluster analysis (CA) were also applied to find out the possible sources of the contaminant in the sediment. Results showed the average concentration of As, Cd, Cr, Pb, Cu and Zn was 9.74 ± 3.57, 2.00 ± 0.85, 48.75 ± 8.92, 29.78 ± 8.39, 5.44 ± 2.03 and 56.94 ± 8.57 mg/kg, respectively. Concentration of Cu, Pb and Zn were within the recommended level whereas the concentration of As, Cd and Cr were suppressed the recommended level of WHO and FAO/WHO standards. PLI, CF and revealed considerably low degree of contamination of the sediment. Geo-accumulation index indicated uncontaminated to moderately contaminated condition of the sediment. Although the values of enrichment factor revealed no potential enrichment for most of the metals, Cd showed a minor enrichment during the winter season. Based on the ecological risk assessment, the sediment from all of the sample locations was found to be of moderate to low risk. PCA and CA analysis revealed the origin of contaminants mainly from anthropogenic sources. Although different metals showed non-carcinogenic risk to the inhabitants, cancer risk values for dermal contact (CR) were much lower than 10 indicating no cancer risk for adult and child. However, the findings also revealed that children were more susceptible to CR compared to adults. The present study concluded that long term dermal contact of the sediment of Bakkhali River estuary will be contagious to the people. Therefore, regular monitoring of the estuarine environment is necessary so that contamination does not get worse.
本研究评估了孟加拉国一条潮汐河的污染现状以及受污染沉积物的后续风险。2020年夏季（4月）和冬季（12月），从巴卡利河河口支流的五个地点采集了沉积物样本。采集的样本按照标准方案进行处理，通过火焰原子吸收光谱仪分析重金属（镉、铬、铜、铅和锌）和类金属（砷）的含量。通过污染负荷指数（PLI）、污染因子（CF）、污染程度（）、潜在生态风险指数（PERI）、因沉积物皮肤接触导致的非致癌和致癌风险（CR）来评估沉积物污染情况。还应用了主成分分析（PCA）和聚类分析（CA）等多元统计分析方法来找出沉积物中污染物的可能来源。结果显示，砷、镉、铬、铅、铜和锌的平均浓度分别为9.74±3.57、2.00±0.85、48.75±8.92、29.78±8.39、5.44±2.03和56.94±8.57mg/kg。铜、铅和锌的浓度在推荐水平范围内，而砷、镉和铬的浓度低于世界卫生组织和粮农组织/世界卫生组织标准的推荐水平。PLI、CF和显示沉积物的污染程度相当低。地累积指数表明沉积物处于未受污染到中度污染的状态。尽管富集因子的值显示大多数金属没有潜在富集，但镉在冬季显示出轻微富集。基于生态风险评估，发现所有采样地点的沉积物风险为中度到低度。PCA和CA分析表明污染物主要来自人为源。尽管不同金属对居民显示出非致癌风险，但皮肤接触的癌症风险值（CR）远低于10，表明成人和儿童没有癌症风险。然而，研究结果还显示，儿童比成人更容易受到CR的影响。本研究得出结论，长期皮肤接触巴卡利河河口的沉积物会对人们有传染性。因此，有必要定期监测河口环境，以免污染情况恶化。
