Exploring the potential of biochar to reduce pesticide uptake in <i>Lactuca sativa</i> and health risk assessment

Abstract

This study investigated the efficacy of rice straw-derived biochar in mitigating cypermethrin (CY) and deltamethrin (DL) uptake in lettuce (Lactuca sativa L.) grown in contaminated sandy loam soil (10 mg kg⁻¹). Biochar was applied at 0%–1% (w/w), with 0.5% showing optimal results: 35% longer shoots (DL), 43%–47% higher soluble proteins, 34% more chlorophyll a, and 54% lower malondialdehyde (MDA), indicating reduced oxidative stress. Nutrient levels also increased, particularly Ca (20%), Mg (33%), and Na (10%). Biochar immobilizes pesticides, reducing the root concentration factor (RCF) and bioconcentration factor (BCF) to 0.05–0.06 mg kg⁻¹ at 1%, thereby limiting translocation and residue risk. CY exhibited lower short-term (0.12) and long-term (0.14) risk than DL. Biochar has enhanced crop resilience, improved food safety, and demonstrated sustainable waste valorization, supporting SDGs 2, 3, and 12.