Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied
Imported rice heavy metal certification was directly informed by this original research, which quantified total arsenic (As), cadmium (Cd), and lead (Pb) in imported rice sold in Iran and then translated those concentrations into population health risk using probabilistic modeling. Researchers collected 200 retail rice samples (Indian and Pakistani origin) from Bandar Abbas during 2023–2024, digested and analyzed them by graphite furnace atomic absorption spectrometry, and applied a Monte Carlo simulation (5,000 iterations) to estimate both noncarcinogenic risk (target hazard quotient, THQ; and total THQ, TTHQ) and carcinogenic risk (incremental lifetime cancer risk, ILCR; and total ILCR, TILCR). This design matters for an HMTC-style program because it links lab results to decision thresholds and shows how “below the legal limit” can still translate into unacceptable risk when exposure is high and variability is considered.
Who was studied
The study did not recruit human participants; instead, it modeled exposure for the Iranian population using two consumer groups—adults and children—because body weight and intake rates strongly influence dose. Rice consumption and body weight were treated as probability distributions in the Monte Carlo framework, allowing the analysis to estimate not just average risk but high-end (eg, 95th percentile) risk that is often more relevant for certification and enforcement. The “who” is therefore best understood as Iranian consumers—especially children—whose chronic dietary exposure was estimated from measured contaminant levels in commonly purchased imported rice varieties.
Most important findings
For imported rice heavy metal certification, the key takeaway is that compliance with maximum limits did not equate to health-protective risk levels, especially for children, and arsenic dominated the hazard profile while As and Cd drove cancer risk.
| Critical point | Details |
|---|---|
| Measured contamination levels differed by origin | Mean concentrations in Pakistani rice were As 0.112 mg/kg, Cd 0.041 mg/kg, Pb 0.062 mg/kg; Indian rice was lower for As (0.077 mg/kg) and Cd (0.019 mg/kg) with similar Pb (0.052 mg/kg). |
| “Below the limit” still produced meaningful risk signals | All mean values were reported below Iranian maximum limits (As 0.2 mg/kg, Cd 0.1 mg/kg, Pb 0.2 mg/kg), yet the authors emphasize that risk estimates were still concerning, particularly where concentrations approached thresholds and exposure is frequent. |
| Noncarcinogenic risk exceeded the safety benchmark when combined | TTHQ exceeded 1 for both adult and child scenarios for both origins (Pakistani: adults 1.322, children 6.503; Indian: adults 1.308, children 6.096), indicating a cumulative noncarcinogenic concern even when individual metals like Pb looked low-risk. |
| Arsenic was the primary noncarcinogenic driver | At the 95th percentile, As hazard quotients exceeded 1 for adults and were far higher for children (eg, Pakistani rice HQAs 1.199 adults and 5.672 children; Indian rice HQAs 1.114 adults and 5.230 children), highlighting why arsenic speciation and stricter action levels are pivotal for certification. |
| Carcinogenic risk was above common acceptability criteria | ILCR values for As and Cd exceeded the stated acceptability threshold (1×10⁻⁴) for both adults and children; total cancer risk (TILCR) was ~1.005×10⁻³ (adults) and 4.010×10⁻³ (children) for Indian rice and 1.307×10⁻³ (adults) and 5.340×10⁻³ (children) for Pakistani rice, with children consistently higher. |
| Analytical rigor supports enforcement-style use | Detection/quantification limits were low (LOD: As 0.0013 ppm, Cd ~0.0010 ppm, Pb 0.0007 ppm; LOQ: As 0.004 ppm, Cd 0.003 ppm, Pb 0.002 ppm) and recoveries were generally ~90–105%, supporting the method’s suitability for certification verification testing. |
Key implications
Imported rice heavy metal certification should move beyond single “maximum limit” checks and explicitly incorporate risk-based triggers: regulators can justify tighter surveillance and potentially lower action levels for arsenic and cadmium where TTHQ and ILCR exceed benchmarks; certification requirements should mandate validated low-LOD methods, defined lot-based sampling, and clear pass/fail rules tied to child-protective exposure assumptions; industry can use supplier controls and origin-based risk ranking (Pakistani samples higher on average) to target mitigation; research gaps include arsenic speciation (inorganic vs total) and wider geographic sampling; practical recommendations include routine probabilistic reporting (eg, 95th percentile risk), transparent COAs, and consumer-risk labeling guidance where warranted.
Citation
Memar M, Ahmadi M, Darvishi Divanmorad AR, Esfandiari Z, Rahmanian O, Soleimani F, Fakhri Y. The concentration of total arsenic, cadmium, and lead in imported rice (Oryza sativa): Probabilistic health risk assessment of Iranian population. Journal of Food Protection. 2026;89:100674. doi:10.1016/j.jfp.2025.100674
Arsenic is a naturally occurring metalloid that ranks first on the ATSDR toxic substances list. Inorganic arsenic contaminates water, rice and consumer products, and exposure is linked to cardiovascular disease, cognitive deficits, low birth weight and cancer. HMTC’s stringent certification applies ALARA principles to protect vulnerable populations.
Cadmium is a persistent heavy metal that accumulates in kidneys and bones. Dietary sources include cereals, cocoa, shellfish and vegetables, while smokers and industrial workers receive higher exposures. Studies link cadmium to kidney dysfunction, bone fractures and cancer.
Lead is a neurotoxic heavy metal with no safe exposure level. It contaminates food, consumer goods and drinking water, causing cognitive deficits, birth defects and cardiovascular disease. HMTC’s rigorous lead testing applies ALARA principles to protect infants and consumers and to prepare brands for tightening regulations.
