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?
This original total diet study quantified Portuguese baseline dietary exposure to inorganic arsenic, cadmium, and lead using harmonized Total Diet Study (TDS) methods, providing evidence directly relevant to heavy metal certification in Portugal. Researchers prepared 227 pooled “as-consumed” samples, mapped to FoodEx2 food groups, and analyzed total arsenic, cadmium, and lead using ISO/IEC-17025-accredited ICP-MS. Inorganic arsenic was conservatively estimated from total arsenic using EFSA’s approach; exposures were modeled using the Observed Individual Mean in MCRA. The study benchmarked exposures against EFSA health-based guidance values and calculated margins of exposure to characterize risk. Key outcomes included mean upper-bound exposures of 0.28 µg/kg bw/day for inorganic arsenic, 1.36 µg/kg bw/week for cadmium, and 0.35 µg/kg bw/day for lead, with bread repeatedly identified as a dominant contributor.
Who was studied?
The target population comprised 3,272 Portuguese residents aged 18–74 years, stratified by sex and by adults (18–64) and elderly (65–74). Food consumption came from a national 24-hour recall survey (2009), used to build a core list of 1,072 foods capturing 95% of intake. From this, 528 items were aggregated to 164 TDS composites, expanded to 227 by including seasonal variants; each sample consisted of twelve subsamples prepared and pooled to mirror real consumption. Collection occurred in Greater Lisbon retail outlets (2014–2016), and exposures were expressed as mean, median, and P95 to reflect average and high consumers. Tap water contributions were estimated deterministically from regulatory monitoring but were minor relative to food sources. Methodological specifics, including left-censored data handling and analytical performance, are documented in the methods and in occurrence tables.
Most important findings
| Critical points for HTMC | Details |
|---|---|
| Population-level exposure (upper bound) | Mean inorganic arsenic 0.28 µg/kg bw/day; cadmium 1.36 µg/kg bw/week; lead 0.35 µg/kg bw/day (Tables 2, 4, 6). These baselines frame certification thresholds for whole-diet risk. |
| Risk characterisation | Inorganic arsenic MOE vs BMDL01_{01}01=0.3–8 ranged ~1.1–29 at mean and 0.4–11 at P95; vs BMDL05_{05}05=0.06 MOE≈0.2–0.1, so concern cannot be excluded. Lead MOE≈4.3 (mean) and 2.2 (P95) vs BMDL01_{01}01=1.5 and MOE≈1.8 (mean) and 0.9 (P95) vs BMDL10_{10}10=0.63, indicating potential cardiovascular/nephrotoxic concern at high intakes. |
| Cadmium TWI exceedance | TWI (2.5 µg/kg bw/week) exceeded in 5.4% of individuals (UB), with all groups above TWI at P95 under UB; LB showed no exceedance at P95. This supports prudent cadmium limits in staples. |
| Dominant contributors | Bread was a common main contributor of inorganic arsenic, cadmium, and lead. Apple led lead exposure at UB; squid led cadmium; semi-skimmed milk and rice were key for inorganic arsenic; coffee and wine added to lead burden. |
| Food-group patterns | Harmonized TDS, “as-eaten” prep, ICP-MS with external calibration, proficiency-tested accuracy; seasonality covered for 21 items; Monte Carlo modeling supports probabilistic exposure profiling. |
| Methodological strengths | Harmonized TDS, “as-eaten” prep, ICP-MS with external calibration, proficiency-tested accuracy; seasonality covered for 21 items; Monte Carlo modeling supports probabilistic exposure profiling. |
| Key uncertainties for certification | High left-censoring for cadmium and lead; inorganic arsenic derived from total arsenic using EFSA factors likely overestimates seafood-related iAs without speciation; consumption data from 2009 may misstate current intakes. Certification should account for these. |
| Tap water contribution | Negligible relative to foods: ≈1% of total inorganic arsenic, 0.2% cadmium, 3% lead, indicating food-centric controls for HTMC. |
| International context | Mean exposures align with several EU and global TDSs for cadmium and lead; inorganic arsenic appears higher than studies that used speciation, underscoring the need for species-resolved targets. |
Key implications
For heavy metal certification in Portugal, regulatory impacts include setting grain- and bread-focused action levels and verifying seafood cadmium and lead via species-specific checks; certification requirements should mandate ICP-MS testing with validated left-censoring protocols and inorganic arsenic speciation for seafood and rice; industry applications include reformulating composite dishes and tightening raw-material sourcing; research gaps involve updated consumption data and lower LODs; practical recommendations prioritize bread, rice, squid, apples, coffee, and wine for targeted surveillance, using harmonized TDS sampling to align facility-level controls with national exposure drivers.
Citation
Vasco E, Dias MG, Oliveira L. The first harmonised total diet study in Portugal: Arsenic, cadmium and lead exposure assessment. Chemosphere. 2025;372:144003. doi:10.1016/j.chemosphere.2024.144003
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.
