Evaluation of soil arsenic pollution and phytoaccumulation capabilities of 24 indigenous plant species in Barak Valley, South Assam, India

Abstract

This study investigated the concentrations of arsenic (As) in soil and plant biomass from the Barak Valley in South Assam, India. Soil samples showed concentrations ranging from 6.06 ± 0.84 mg/kg to 18.61 ± 1.52 mg/kg, with an average of 10.60 ± 3.15 mg/kg, 41.67% of the sample exceeding uncontaminated ranges (0.1–10 mg/kg). Ecological risk assessments such as contamination factors, pollutant load index, geo‐accumulation index, and anthropogenicity identified varying contamination levels across sampling points. A total of 24 plant species were collected, ferns (two species), shrubs (five species), grass (six species), and herb (11 species). The concentration of As in different plants types decreased in the order of fern (393.45 ± 159.63 mg/kg) > shrub (20.48 ± 7.25 mg/kg) > herb (17.92 ± 13.75 mg/kg) > grass (14.98 ± 13.80 mg/kg). Plant species, namely Pityrogramma calomelanos, Christella dentata, Mimosa pudica, Chromolaena odorata, Leucas aspera, Persicaria decipiens, Melastoma malabathricum, and Clerodendrum infortunatum, accumulated higher concentrations of As in their above‐ground parts compared to roots and were categorized as tolerant accumulators (TF > 1). By incorporating these plant species into phytoextraction strategies, the region can benefit from their unique properties and abilities to effectively remediate arsenic‐contaminated sites, ultimately improving the affected areas' environmental and human health conditions.