Rapid urbanization and industrial growth have triggered heavy metal contamination in agricultural soil in Dhaka, which is a serious concern for ecological risk and public health issues. In this study, fifty-four soil samples from agricultural lands of Dhaka had been analyzed for assessing accumulation, spatial enrichment, ecological risk and sources apportionment of heavy metals using a combined approach of self-organizing map (SOM), positive matrix factorization (PMF), geographical information system (GIS), and enrichment factor (EF). The results of the enrichment factor, geoaccumulation index and contamination factor index showed that more than 90% of the soil samples were polluted by higher levels of Cr and Cd. The mean pollution load index (PLI) results demonstrated that about 73% of soil samples were moderately polluted by heavy metals. Based on SOM and PMF analysis, four potential sources of heavy metals were found in this study area: (i) agrochemical and sewage irrigation (Cd-As); (ii) combined effect of agriculture, industrial and natural sources (Mn, Co, Ni and Zn); (iii) atmospheric deposition and industrial emission (As-Pb); (iv) chemical and leather tanning industries (Cr). The ecological risk index demonstrated that in terms of Cd content, about 75% of soil samples were moderate to high risk, and 20% were moderate to considerable ecological risk, which was the serious environmental, ecological, and public health concern. The spatial projection of ecological risk values showed that the southern part of Dhaka (Keraniganj Upazila) is a high ecological risk in terms of heavy metal pollution. These risk maps in agricultural soils may play a vital role in reducing pollution sources; so that zonal pollution control, as well as ecological protection, may be achieved in this resource-based agricultural land.

快速的城市化和工业增长已导致达卡农业土壤中的重金属污染，这是对生态风险和公共卫生问题的严重关注。在这项研究中，使用自组织图（SOM），正矩阵分解（PMF）的组合方法，分析了达卡农业土地的54个土壤样品，以评估重金属的积累，空间富集，生态风险和源分配。 ），地理信息系统（GIS）和浓缩因子（EF）。富集因子，地质积累指数和污染因子指数的结果表明，超过90％的土壤样品被较高的Cr和Cd污染。平均污染负荷指数（PLI）结果表明，约73％的土壤样品被重金属中等污染。根据SOM和PMF分析，在该研究区域中发现了四种潜在的重金属来源：（i）农业化学和污水灌溉（Cd-As）；（ii）农业，工业和自然资源（锰，钴，镍和锌）的综合影响；（iii）大气沉积和工业排放（As-Pb）；（iv）化学和皮革制革工业（Cr）。生态风险指数表明，就镉含量而言，大约75％的土壤样品为中度至高风险，而20％的土壤为中度至相当大的生态风险，这是对环境，生态和公共健康的严重关注。生态风险值的空间预测表明，达卡南部（Keraniganj Upazila）在重金属污染方面具有很高的生态风险。农业土壤中的这些风险图可能在减少污染源方面起着至关重要的作用；因此，在该资源型农业土地上可以实现区域污染控制和生态保护。