The soil-rice system in rural and peri-urban areas of the lower Brahmaputra valley, northeast India was investigated for heavy metal(loid)s using Nemerow’s pollution index (PI_N) and potential ecological risk index (RI). Potential health risk due to rice consumption grown in the region was assessed in terms of carcinogenic and non-carcinogenic risks. Around 95% of the soil showed acidic nature that ranged from weakly acidic to strongly acidic soil. In terms of PI_N, 27.3% of the sampling sites were heavily polluted (PI_N≥3), 34.8% moderately, and 37.9% were slightly polluted. The Pb concentration was comparably higher in 57.1% of the rice grain samples and the mean As level (0.17 mg kg⁻¹) was close to the WHO limit. The non-carcinogenic risk in terms of hazard quotient (HQ) was high primarily due to As (HQ > 1), whereas other metals had limited contribution (HQ < 1). The carcinogenic risk based on total cancer risk (TCR) values for adults and children ranged between 0.0039 – 0.019 and 0.0043–0.0211, respectively, exceeding the maximum acceptable level of 1 × 10⁻⁴. Among the rice varieties, for non-carcinogenic risks, the maximum hazard index (HI) was noticed for Bahadur and the minimum for Ranjit. Whereas for carcinogenic risks, the maximum TCR was observed for Mahsuri and the minimum for Moynagiri.

利用Nemerow污染指数（PI _N）和潜在生态风险指数（RI）对印度东北部Brahmaputra山谷农村和近郊地区的土壤-水稻系统中的重金属（类）进行了调查。根据致癌和非致癌风险评估了该区域因种植大米而导致的潜在健康风险。大约95％的土壤呈酸性，范围从弱酸性到强酸性。来讲PI _Ñ，采样点的27.3％是严重污染（PI _Ñ ≥3），34.8％中度，和37.9％的轻度污染。57.1％的大米样品中的铅含量相对较高，平均砷水平（0.17 mg kg^-1）接近WHO限值。就危险商（HQ）而言，非致癌风险很高，这主要归因于砷（HQ> 1），而其他金属的贡献有限（HQ <1）。成人和儿童基于总癌症风险（TCR）值的致癌风险分别在0.0039 – 0.019和0.0043–0.0211之间，超过最大可接受水平1×10 ^-4。在水稻品种中，对于非致癌风险，Bahadur的最大危害指数（HI）最高，Ranjit的最小危害指数最低。对于致癌风险，Mahsuri观察到最大TCR，Moynagiri观察到最小。