Abstract：
For decades, rivers have been used for transporting pollutants loaded with heavy metals (HMs) causing severe pollution in downstream. The current study aimed to review the levels and sources of 10 HMs, viz. As, Pb, Cd, Cr, Fe, Mn, Cu, Co, Ni, and Zn in the surface water of the rivers in Bangladesh. The PRISMA criteria were used to conduct a systematic review of the available literature published between 2001 and 2020, and thus a total of 55 documents were finally selected for review. The mean concentration of each HM exceeding the threshold limits as per World Health Organization (WHO), the United States Environmental Protection Agency (USEPA), and Department of Environment (DoE), Bangladesh standards were higher in the last decade (2011-2020) than in the previous one (2001-2010). Most HM concentrations in water were found above the threshold limits in three divisions (Dhaka, Rajshahi, and Chattogram). The Buriganga River in Dhaka has been the top polluted river in Bangladesh. Among the 10 HMs, six metals (As, Pb, Cd, Cr, Fe, and Mn) exceeded the limit set by WHO, USEPA, and DoE in all three seasons, where mean values of most of the HMs were found to be the highest in the summer season. Statistical analyses identified possible sources of HMs such as natural weathering, electroplating, fertilizers and pesticides, mining and manufacturing, textiles, coal mining and burning, batteries, and paint industries. Strong legislations and regulations, awareness programs, continuous monitoring, and comprehensive research are urgently needed to control riverine HMs pollution in Bangladesh.
摘要：
几十年来,河流已用于运输含有重金属（HM）的污染物，从而在下游造成严重污染。目前的研究旨在审查10个HMs的水平和来源，viz.As,Pb,Cd,Cr,Fe,Mn,Cu,Co,Ni,孟加拉国河流地表水中的锌。使用PRISMA标准对2001年至2020年之间发表的现有文献进行了系统的审查，因此最终总共选择了55篇文献进行审查。每个HM的平均浓度超过世界卫生组织（WHO）的阈值限值，美国环境保护署(USEPA)和环境部（DoE），孟加拉国的标准在过去十年（2011-2020年）高于上一个十年（2001-2010年）。在三个分区中发现水中的大多数HM浓度高于阈值极限(达卡，Rajshahi,和Chattogram）。达卡的布里甘加河一直是孟加拉国污染最严重的河流。在10个HM中，六种金属(As，Pb,Cd,Cr,Fe,和锰)超过了世卫组织设定的限值，USEPA,在所有三个季节里，发现大多数HM的平均值在夏季最高。统计分析确定了HMs的可能来源，如自然风化，电镀,化肥和杀虫剂,采矿和制造业，纺织品,煤炭开采和燃烧，电池,和油漆工业。强有力的法律法规,意识计划，连续监测,迫切需要全面的研究来控制孟加拉国的河流HMs污染。
