The Meghna River, the largest and the widest river in Bangladesh, is important for navigation, irrigation, fish spawning and shelter, industrial usages, and drinking water sources for millions of people living in nearby areas. The present study illustrated the seasonal variation of some physicochemical parameters and the four heavy metals (Cr, As, Cd, and Pb) distribution in the surface water of Meghna River estuary. It also evaluated the human health risk for adult and children due to directly contact with the surface water through ingestion and dermal pathways. The ranges of metal concentration in the study area were found in the descending order as: Cr (0.036–0.054; mean 0.045 ± 0.005) > As (0.012–0.036; mean 0.024 ± 0.007) > Cd (0.009–0.050; mean 0.018 ± 0.012) > Pb (0.007–0.014; mean 0.009 ± 0.007). In most cases, the concentrations of As, Cr, Pb, and Cd surpassed the guideline limits of human consumption. However, the one-way ANOVA study revealed that the average concentrations of the selected metals in the ten sampling sites were not significantly different at a 95% confidence level. Therefore, it is assumed that the metal contamination in the study area might have been caused due to the anthropogenic sources along with the natural phenomenon. The distribution of the metal contents and the physicochemical parameters in the surface water greatly were significantly different concerning both winter and summer seasons at a 95% confidence level. The evaluated hazard quotient (HQ) and the hazard index (HI) for the investigated metal compounds were in the acceptable limit (< 1). In addition, the attribution of metal contents did not overweigh the carcinogenic risk (CR) range (10^–6 to 10^–4), and the adults are more susceptible than the children. Although the risk is within the acceptable level, but adequate monitoring aspects should be implemented to control surface water pollution especially for the metal discharge to the river estuary.

梅格纳河是孟加拉国最大、最宽的河流，对于生活在附近地区的数百万人的航行、灌溉、鱼类产卵和庇护所、工业用途和饮用水源非常重要。本研究阐明了梅格纳河口地表水中一些理化参数和四种重金属（Cr、As、Cd和Pb）分布的季节性变化。它还评估了通过摄入和皮肤途径直接接触地表水对成人和儿童的人类健康风险。研究区金属浓度范围从低到高依次为：Cr（0.036-0.054；平均0.045±0.005）>As（0.012-0.036；平均0.024±0.007）>Cd（0.009-0.050；8±0） 0.012) > Pb (0.007–0.014；平均 0.009 ± 0.007)。在大多数情况下，As、Cr、Pb 和 Cd 的浓度超过了人类消费的指导限值。然而，单向方差分析研究表明，在 95% 的置信水平下，十个采样点中所选金属的平均浓度没有显着差异。因此，推测研究区的金属污染可能是由人为来源和自然现象引起的。地表水中金属含量的分布和物理化学参数在 95% 的置信水平下在冬季和夏季都有显着差异。所研究金属化合物的评估危害商数 (HQ) 和危害指数 (HI) 均在可接受的范围内 (< 1)。此外，^–6至 10 ^–4 )，成人比儿童更易感。虽然风险在可接受的范围内，但应采取足够的监测措施来控制地表水污染，尤其是金属向河口的排放。