Islam et al. 2024 — Systematic review of heavy metals in Bangladeshi fruits

This systematic review synthesized findings from 10 primary studies (2012–2022) measuring heavy metal concentrations in locally produced fruits in Bangladesh. The review compiled concentration ranges across 22 fruit varieties for As, Cd, Pb, Cr, Mn, Ni, Cu, Zn, and Hg, then estimated carcinogenic and non-carcinogenic health risks using estimated daily intake (EDI), target hazard quotient (THQ), and target cancer risk (TR). Several fruits — banana, mango, guava, litchi, blackberry, lemon, and tamarind — contained Pb and Cd above WHO/FAO maximum allowable concentrations, and As exceeded the safety threshold in mango and guava (up to 1.3 mg/kg FW). Cancer risk (TR) from As, Cd, Cr, and Ni exceeded acceptable levels for most fruit types, indicating potential long-term carcinogenic risk for regular consumers of Bangladeshi fruits.

Key numbers

All metals reported on fresh weight (FW) basis. Analytical methods across included studies: ICP-MS (n=4), ICP-OES (n=1), AAS (n=4), FAAS (n=1). Quality assurance reported in 8 of 10 studies (IQCs, CRMs, or accuracy/precision analysis).

Total target hazard quotient (TTHQ) exceeded 1 for 7 fruits (banana, mango, jackfruit, papaya, guava, pineapple, strawberry), with guava (9.43), mango (8.25), and papaya (8.04) highest. Combined hazard index (HI) across all fruits = 45.93. Total cancer risk for Cd ranked highest (0.037) followed by Ni (0.024) and As (0.013); only Pb was within the acceptable TR level.

Methods (brief)

Systematic review following PRISMA guidelines. Databases: PubMed, Google Scholar, and manual Google searching. Inclusion criteria: cross-sectional studies in Bangladesh, 2012–2022, reporting heavy metal concentrations in edible fruit portions in English. Of 1,458 retrieved articles, 10 were included after screening. Highest metal concentrations per fruit used for risk calculations, which the authors acknowledge may overestimate risk. The review used EDI, THQ (using EPA RfDs), and TR (using IRIS oral carcinogenic slope factors) for As, Cd, Pb, Cr, and Ni. All EDI values were below MTDI for all fruits.

Implications

Certification: Confirms elevated Pb and Cd in tropical fruits from Bangladesh relative to WHO/FAO MACs; relevant for any product formulations using Bangladeshi-sourced mango, guava, jackfruit, or banana. Cd in stone apple (0.64 mg/kg FW) is ~12x the WHO MAC.

Courses: Illustrates the soil-to-crop pathway for arsenic from groundwater irrigation in Bangladesh; also demonstrates the THQ/TR framework for health risk communication.

App: Supports elevated contamination flags for tropical fruits (mango, guava, banana) when declared country-of-origin is Bangladesh. As, Cd, Pb, Cr all exceeded MACs in multiple fruits.

Wiki pages this source may touch

• fruits
• banana
• mango
• guava
• fresh-fruit
• arsenic-total
• cadmium
• lead
• chromium
• nickel
• mercury-total
• manganese
• copper
• zinc

Verification notes

• Cross-vendor audit (Codex, 2026-05-17) corrected the truncated PDF raw_path, changed unspeciated arsenic from As to tAs, added Mn/Cu/Zn to frontmatter because the review reports those metals, removed non-taxonomy ingredient slugs (papaya, jackfruit) in favor of fruits, removed invented matrix edible-fruit-flesh, and modernized the wiki-link section. The source itself reports Pb as ND-2.4 mg/kg in the abstract/table while the narrative names mango at 0.75 mg/kg as the highest Pb level; the Key numbers row now flags that internal source tension rather than assigning 2.4 to mango.
• 2026-05-19 brand-firewall recheck under stricter 2026-05-17 Part 12 reading: no commercial brand names in page body; the only varietal-name references in the underlying PDF (Bangla kola, Chapa kola, Sabri kola, Sagor kola — banana cultivars from Sajib et al. 2013) are botanical/cultivar identifiers, not commercial brands, and were never carried into this wiki page. Page is clean.
• 2026-05-19 corrected Zn row in Key numbers: previously stated “Banana (134 max)”, but Table 2 shows banana Zn range is 0.24–102 mg/kg. The 134 max value corresponds to papaya per Table 2, while the narrative on p.7 names banana at 134 (“banana contained the highest concentration of Zn (134 mg/kg of FW) followed by papaya and guava”) — internal source contradiction now flagged in the table row.
• Audit subagent (2026-05-19) flagged Cd row as missing an internal-contradiction flag (claiming Table 2 stone-apple = 0.51 vs narrative 0.64). Verified against Table 2 p.6 — stone-apple Cd IS 0.64 in Table 2 (the subagent confused stone-apple with indian gooseberry/tamarind, both at 0.51). Table and narrative agree on stone-apple 0.64; no contradiction exists. Finding rejected as false positive.
• Audit subagent (2026-05-19) flagged Mn/Cu/Zn missing from “Wiki pages this source may touch” despite being in metals: frontmatter. Verified; added manganese, copper, zinc for symmetry.
• Potential future ingredient slugs surfaced for Karen if the fruit corpus accumulates enough independent papers: papaya, jackfruit, litchi, blackberry, pineapple, pomegranate, and tamarind.

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.