This systematic review (PROSPERO CRD42021235435) searched five databases and identified 26 intervention studies from 21 low- and middle-income countries that aimed to reduce cadmium exposure during pregnancy and childhood. Interventions ranged from nutritional supplements, probiotic yogurt, dietary education (rice cooking methods), chelation therapy, and indoor air filtration to agricultural soil remediation (biochar, organic amendments). The review found that several interventions showed measurable reductions in cadmium body burden or food-chain concentrations, but none offered a realistic scalable solution. Rice-specific interventions (rice cooking method education, rice paddy soil biochar amendment) were notably represented. The finding that no existing intervention robustly addresses Cd pollution at scale underscores the ongoing need for upstream source control and supply-chain screening.
Key numbers
Studies included: 26 from 21 LMICs. Human intervention types: nutritional supplements (n=7 studies), medicine/clinical care (n=2), rice cooking education (n=1). Environmental intervention types: agricultural soil remediation, indoor air filtration, policy-level changes (n=4). Key effect sizes from highest-quality studies: urinary Cd in children decreased from mean 12.8 to 9.4 µg/L after dietary intervention (El-Soud et al., Egypt; n=65); biochar application at 10% rate reduced Cd in rice and hazard quotient to acceptable levels (Khan et al., China; n not specified). Indoor air cleaners reduced indoor Cd concentrations during pregnancy.
Methods (brief)
Systematic review of five databases (Scopus, Web of Science, PubMed, Global Health Medicus, Greenfile); search date November 2020. PICO inclusion criteria: pregnant women/children in LMICs, interventions to reduce Cd exposure, human or environmental biomonitoring outcomes. Synthesis without meta-analysis (SWiM/narrative synthesis) due to heterogeneity. Quality assessment using modified GRADE criteria (17-point scale). PRISMA reporting.
Implications
Certification: Reinforces that dietary Cd exposure in vulnerable populations (pregnancy, childhood) is a persistent global problem with limited mitigation options; supports HMT&C rationale for strict Cd limits in foods consumed by these populations. Courses: Provides evidence base for mitigation module content, particularly rice cooking method effects and biochar soil amendment; useful for brand QA training on supply-chain Cd reduction. App: Informs the mitigation-options framework for rice and vegetable ingredients; rice cooking method is a documented lever for reducing dietary Cd exposure. Mitigation: Directly relevant to cadmium-dietary-reduction if that page is created.