ABSTRACT

Heavy metal contamination in groundwater is a global health concern and its gravity is higher in India, as more than 80% of the rural and 50% of the urban population rely on it for drinking purposes. The present study comprehensively analysed the source, distribution pattern, and seasonal flux of heavy metals in the groundwater sources of Malappuram district, a coastal landmass in peninsular India, using multivariate statistics, pollution indices, and interpolation models in GIS. In three seasons, higher incidences of Pb, Ni and Cd and lower persistence of Zn and Cu were observed during the study period. Heavy metal Pollution Index (HPI) was highest during the pre-monsoon season as 57.57% of the samples were above the critical value. The Metal Index (MI) was higher in coastal areas and is linked to fluvial deposits. More than 77% of the samples were noted to be acidic in all the seasons due to geogenic influxes that accelerated the dissolution of toxic metals upon contact. The HPI interpolation model reveals less heavy metal contamination in the coastal plains, compared to midland and highland urban centres, indicating the least influence of terrain characteristics in the translocation of heavy metals in the groundwater sources.

摘要

地下水中的重金属污染是一个全球性的健康问题，其严重程度在印度更高，因为超过 80% 的农村人口和 50% 的城市人口依赖地下水饮用。本研究利用GIS中的多元统计、污染指数和插值模型，综合分析了印度半岛沿海陆地马拉普拉姆区地下水源中重金属的来源、分布格局和季节性通量。在研究期间观察到三个季节，铅、镍和镉的发生率较高，而锌和铜的持久性较低。季风前的重金属污染指数（HPI）最高，57.57%的样本高于临界值。沿海地区的金属指数 (MI) 较高，并与河流沉积物有关。由于地质流入加速了有毒金属在接触时的溶解，超过 77% 的样品在所有季节都呈酸性。与中部和高地城市中心相比，HPI 插值模型显示沿海平原的重金属污染较少，表明地形特征对地下水源中重金属易位的影响最小。