Deka et al. 2023 — Monitoring strategies for heavy metals in foods and beverages (IntechOpen chapter)

This IntechOpen open-access book chapter reviews analytical monitoring methods, exposure parameters (RDA, EDI, MPL, THQ, HI, TCR), and remediation tactics for heavy metals in foods and beverages. The chapter compiles maximum permissible limits (MPL) from WHO, USEPA, JECFA, CalEPA, ATSDR, the Standards Organisation of Nigeria (SON), and the International Organization of Grapes and Wine (OIV), lists oral reference doses for several metals, and summarizes analytical techniques (ICP-OES, ICP-MS, FAAS variants including HGAAS and CVAAS, TRXF, CR-SENLIBS, electrochemical aptasensors). Remediation strategies covered include nanotechnological innovations, chelating ligands, plant phenolic compounds, and microbial bio-absorbents (gram-positive and gram-negative bacteria, cyanobacteria, yeast, fungi, algae). No primary food-concentration measurements are reported; the chapter is a methods, regulatory, and remediation summary with educational orientation. Authors are affiliated with the Department of Chemistry, Central Institute of Technology Kokrajhar (Assam, India).

Key numbers

Maximum permissible limits compiled in Table 1 of the chapter

The chapter’s Table 1 mixes water-MPLs, food-PTWIs/PTMIs, dietary daily limits, and airborne limits into a single table. Wiki users should consult the primary regulatory source before applying any of these to certification work.

Water and food limits:

• Cd — 0.005 mg/L (EPA), 0.003 mg/L (WHO)
• tHg — 0.002 mg/L (EPA), 0.001 mg/L (WHO)
• Pb — PTWI 0.025 mg/kg bw/week (JECFA, since formally withdrawn in 2010), 0.01 mg/L (WHO drinking-water guideline)
• As — 0.010 mg/L MCL (USEPA, drinking water)
• Cr-VI — 0.003 mg/kg bw/day
• Sb — 5 µg/day
• Ba — 2.0 mg/L (EPA, drinking water)
• Be — 0.004 mg/L (EPA, drinking water)
• Fe — PTMI 0.8 mg/kg bw/day (WHO)
• Mn — 11 mg/day (NAS)
• Mg — 350 mg/day

Airborne (inhalation) reference values that the chapter includes alongside food MPLs:

• Co — 5×10⁻⁶ mg/m³ (CalEPA), 3×10⁻⁵ mg/m³ MRL (ATSDR)

Oral reference doses summarized in Figure 3 (USEPA, mg/kg bw/day)

Fe 0.7; Zn 0.3; Mn 0.14; Ca 0.04; Pb 0.004; As 0.003; Ni 0.002; Cd 0.001; Co 0.0003.

Cancer slope factors (USEPA) cited for TCR

• Pb — 36 mg/kg/day
• Cd — 15 mg/kg/day

The chapter labels these “Cn” but the surrounding text identifies them as USEPA-prescribed cancer slope factors used in TCR = CSF × EDI.

Interpretation thresholds the chapter attributes to NYSDOH

TCR ≤ 10⁻⁶ → low risk; 10⁻³ to ≥10⁻¹ → moderate risk; above 10⁻¹ → too high.

Risk parameters the chapter walks through

• RDA examples cited: Co 100 µg/day; Cu 15–500 µg/kg bw/day; Fe and Mn upper bounds 10–18 mg/day and 2–5 mg/day; Ni TDI 5 µg/kg bw/day; Pb TDI 7.14 µg/kg bw/day (60 kg adult).
• EDI = (C_metal × Q_ig) / bw; THQ = (E_fr × E_Dur × C_metal × S_ig)/(O_Rf × bw × ATn) × 10⁻³; HI = Σ THQ_metals; TCR = CSF × EDI.
• The chapter states “If THQ < 1, the food or beverage is less carcinogenic” — this is a misstatement in the source itself, since THQ is a non-carcinogenic hazard quotient. The chapter then defines a separate TCR equation for carcinogenic risk. Cite cautiously.

Methods (brief)

Narrative review chapter, IntechOpen open-access (CC BY 3.0), DOI: 10.5772/intechopen.110542. No primary contamination data. Evidence tier B: useful as an analytical-methods reference and for the consolidated MPL/parameter framework; not citable as direct evidence for occurrence values. MPL values must be re-verified against primary regulatory sources before any certification-document use because the chapter mixes water and food limits in the same table and propagates a known JECFA PTWI value (0.025 mg/kg bw/week for Pb) that was formally withdrawn in 2010.

Analytical techniques surveyed:

• FAAS family (FAAS, HGAAS, CVAAS) — accessible, lower sensitivity; HGAAS used for hydride-forming metals (As, Pb, Se, Sn); CVAAS for Hg.
• ICP-OES — argon-plasma multi-element, sensitive, requires liquid sample.
• ICP-MS — most sensitive, LODs from ppb to ppt range, gold-standard for trace and ultra-trace analysis.
• TRXF — qualitative, low sample mass, fast (100–1000 s), suited to liquid and powder samples including wines.
• CR-SENLIBS — emerging laser-induced breakdown spectroscopy variant for liquid-on-solid sample preparations.
• Electrochemical aptasensors — listed but not detailed.

Table 2 of the chapter compiles digestion methods and analytical techniques for a non-systematic list of food/beverage matrices (cocoa beans, fruits/vegetables/cereals, green coffee bean, potato chips and biscuits, seafood/vegetables/stimulant drinks, soft drinks, carbonated flavored yogurt and juice drinks, vegetables, generic food, soft drinks) drawn from a dozen primary references.

Implications

Certification: Useful for the testing-methodology section of auditor guidance — the FAAS/GFAAS/ICP-OES/ICP-MS trade-off discussion supports the standard pick of ICP-MS as the gold standard for low-level detection and FAAS as the accessible-but-insensitive alternative. The remediation taxonomy (nanoparticles, chelating ligands, plant phenolics, microbial bio-absorbents) is too high-level for a mitigation playbook but can frame the supply-chain reduction module.

Courses: Good background reference for testing-methods and remediation modules. The consolidated parameter framework (RDA / EDI / MPL / THQ / HI / TCR) is teaching-grade material; the chapter’s misstatement that “THQ < 1 → less carcinogenic” should be corrected in any teaching adaptation.

App: Not a source of concentration values. The analytical-method LOD descriptions inform minimum quantification thresholds used in app uncertainty estimates, but no direct ppb data are extractable.

Verification notes

Enhancement run 2026-05-18 (cite-key existed before 2026-05-14; routing audit flagged as advisory-malformed for missing ingredients/jurisdictions). Defects corrected against the source PDF:

• Removed invented products: ["[[products/spices]]"] slug. The chapter does not single out spices; Table 1 and Table 2 cover a broad sweep of food and beverage matrices with no specific product focus. products: [] reflects the chapter’s methodology-review scope. Source verification: full chapter read pages 1–14; “spice” or “spices” does not appear in the chapter body.
• Corrected Co exponents in Key numbers — chapter Table 1 shows CalEPA 5×10⁻⁶ mg/m³ and ATSDR MRL 3×10⁻⁵ mg/m³ (both with negative exponents, both inhalation/airborne limits). The pre-existing page had transposed these as positive exponents and presented them alongside food MPLs without separating airborne from food limits.
• Expanded metals: from [Pb, Cd, tHg, Cr, Ni, Al, tAs] to include Cr-VI (chapter explicitly cites IARC Cr-VI classification), Sb, Mn, Fe, Co, Ba, Be — all substantively present in Table 1 and the chapter’s parameter discussions.
• Added jurisdictions: [IN] (authors at Central Institute of Technology Kokrajhar, Assam).
• Expanded matrices: to reflect chapter scope (added non-alcoholic-beverages, soft-drinks, wine, drinking-water).
• Added oral reference doses (Figure 3), cancer slope factors (Pb and Cd from §2.2.5), and NYSDOH TCR interpretation thresholds that the prior page had omitted.
• Flagged the chapter’s internal contradiction (THQ described as carcinogenic indicator) so future synthesis does not propagate it.

Preserved fields: cite_key, raw_handle, raw_path, access_url, source_type, evidence_tier, sample-population framing, license (refined to CC BY 3.0 per the chapter’s printed license stamp).

Audit subagent (2026-05-18) flagged three ⚠️ advisory items — all applied: (i) added OIV to the agency list in the introduction (chapter p. 2 cites OIV alongside WHO/USEPA/JECFA/SON, the prior draft omitted it); (ii) added [[metals/chromium]] alongside [[metals/chromium-hexavalent]] in the wiki-pages-touched section (Table 1 row 4 covers Cr generally as well as the Cr-VI carcinogenicity classification); (iii) noted that the matrices: entries (alcoholic-beverages, non-alcoholic-beverages, herbal-drinks, soft-drinks, wine, drinking-water) are routing-input descriptors rather than slugs from the closed taxonomy-snapshot vocabulary — they exist as free-form matrix labels that the routing layer fans out, and the routing audit accepts them without unresolved entries. No findings rejected.

Wiki pages this source may touch

• icp-ms
• aas
• icp-oes
• trxf
• lead
• cadmium
• mercury-total
• arsenic-total
• chromium
• chromium-hexavalent
• nickel
• aluminum
• antimony
• manganese
• iron
• cobalt
• barium
• beryllium

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.