Morshed et al. 2024 - Heavy metals in experimental poultry organs, Bangladesh

This Research Square preprint reports a 28-day experimental feeding study in which broiler chickens were fed poultry feed intentionally adulterated with graded concentrations of lead (Pb), cadmium (Cd), and chromium (Cr). The authors measured Pb, Cd, and Cr in feed and in chicken muscle, bone, liver, kidney, and lung after slaughter. The source is useful as a mechanistic dose-response and organ-distribution study; it is not retail occurrence evidence for ambient commercial chicken because the feed metal additions were deliberate and high-dose.

Key numbers

All feed values below are source-reported in mg/kg from Table 3.1. Organ-deposition values are source-reported on a dry basis in mg/kg from Table 3.5. The PDF rendering of Table 3.5 is incomplete and internally inconsistent; this page reports only values visible in the PDF and flags the source-internal issue in Verification notes.

Feed concentrations, Table 3.1:

• Pb in feed: C0 = 0; C1 = 0.72 +/- 0.20; C2 = 1.52 +/- 0.11; C3 = 2.66 +/- 0.66; C4 = 4.34 +/- 0.06; C5 = 10.58 +/- 3.83; C6 = 18.21 +/- 4.54; C7 = 46.14 +/- 21.20 mg/kg.
• Cd in feed: C0 = 0; C1 = 0.90 +/- 0.53; C2 = 1.40 +/- 0.07; C3 = 2.03 +/- 0.03; C4 = 2.63 +/- 1.37; C5 = 9.18 +/- 2.84; C6 = 22.67 +/- 9.15; C7 = 40.46 +/- 12.25 mg/kg.
• Cr in feed: C0 = 0.88 +/- 0.47; C1 = 1.77 +/- 0.91; C2 = 2.29 +/- 0.54; C3 = 2.96 +/- 0.95; C4 = 3.64 +/- 0.30; C5 = 10.86 +/- 4.86; C6 = 24.37 +/- 1.40; C7 = 45.90 +/- 20.08 mg/kg.
• Day-28 total feed consumption ranged from 2792.50 +/- 209.08 g per bird in C0 to 3495 +/- 278.25 g per bird in C1. The authors state that feed intake did not change monotonically with increasing heavy-metal concentration.

Growth and feed conversion:

• Final mean body weight after 28 days: C0 = 1552.5 +/- 245.41 g; C1 = 1560 +/- 124.90 g; C7 = 925 +/- 135.28 g. The source states that body weight declined from C0/C1 toward C7 as feed metal concentration increased.
• Average total feed conversion ratio after 28 days: C0 = 1.81 +/- 0.14; C1 = 2.24 +/- 0.08; C2 = 2.29 +/- 0.19; C3 = 2.30 +/- 0.28; C4 = 2.29 +/- 0.06; C5 = 2.34 +/- 0.10; C6 = 2.96 +/- 0.06; C7 = 3.53 +/- 0.44.

Cadmium organ deposition, visible Table 3.5 block:

• C0: muscle, bone, liver, kidney, and lung all <BDL.
• C1: muscle 0.31 +/- 0.17; bone 0.65 +/- 0.05; liver 1.09 +/- 0.09; kidney <BDL; lung 0.10 +/- 0.03.
• C5: muscle 1.26 +/- 0.15; bone 5.66 +/- 0.47; liver 6.49 +/- 0.50; kidney 2.63 +/- 0.22; lung 0.87 +/- 0.26.
• C7: muscle 6.57 +/- 0.31; bone 20.72 +/- 0.54; liver 43.36 +/- 0.63; kidney 8.72 +/- 0.45; lung 2.22 +/- 0.45.
• The visible Cd table values place liver above bone at the highest dose, although the abstract states that bone had the highest Cd concentration. This page follows the visible table values and treats the abstract/table mismatch as a source-internal inconsistency.

Chromium organ deposition, visible Table 3.5 block:

• C0: muscle 0.23 +/- 0.04; bone 0.41 +/- 0.01; liver <BDL; kidney <BDL; lung <BDL.
• C1: muscle 0.37 +/- 0.05; bone 0.60 +/- 0.05; liver 0.32 +/- 0.02; kidney <BDL; lung 0.39 +/- 0.07.
• C2: muscle 0.59 +/- 0.03; bone 0.93 +/- 0.03; liver 0.55 +/- 0.03; kidney <BDL; lung 0.63 +/- 0.03.
• C3: muscle 0.97 +/- 0.04; bone 1.43 +/- 0.05; liver 0.68 +/- 0.02; kidney <BDL; lung 0.96 +/- 0.04.
• The abstract states that the highest Cr amount was found in liver, but the PDF table rows for C4-C7 are blank/unreadable in this copy; this page does not report high-dose Cr organ values not visible in the source.

Histopathology and modeled risk:

• The abstract reports that liver, kidney, intestine, skin, and lung were more affected histologically than brain after heavy-metal feeding.
• The source states that THQ and target cancer risk (TR) increased with increasing heavy-metal concentration; numerical THQ/TR values are presented in figures whose data tables are not readable in this PDF copy.

Methods (brief)

Experimental feeding study; 24 day-old broiler chickens were divided into eight groups of three birds each and fed starter feed from days 1-22 and grower feed from days 23-28. Groups C1-C7 received feed manually adulterated with lead nitrate, cadmium chloride, and chromium nitrate solutions at seven graded concentrations; C0 received market feed without artificial Pb/Cd addition. Feed and organ samples were dried at 105 deg C. Feed samples and approximately 2 g dried organ samples were digested with concentrated nitric acid/perchloric acid (3:2 v/v), then brought to 25 mL with distilled water. Pb, Cd, and total Cr were measured by atomic absorption spectrophotometry (Thermo Scientific iCE 3000); no chromium speciation was performed. Moisture was measured with a MAC 50 RADWAG moisture analyzer. The risk calculations used RfDs of 0.0035 mg/kg-bw/day for Pb, 0.00083 mg/kg-bw/day for Cd, and 0.0083 mg/kg-bw/day for Cr. Key limitations: preprint status, n=3 birds per group, deliberate high-dose feed adulteration, and incomplete/contradictory Table 3.5 rendering in the available PDF.

Implications

Certification (HMTc): This source contributes mechanistic evidence that poultry organs can accumulate Pb, Cd, and Cr differently from edible muscle under contaminated-feed exposure. Because the feed was experimentally adulterated and the sample size was three birds per group, the numeric organ concentrations should not be used as ambient commercial-poultry occurrence baselines.

Courses: Useful teaching case for feed-to-tissue transfer, organ-distribution uncertainty, and why source-table QA matters before using organ-meat values in standards work.

App: The source may inform chicken, poultry, and organ-meat source-side context for Pb, Cd, and total Cr, but values from the high-dose experimental groups should remain separated from retail/market occurrence datasets.

Wiki pages this source may touch

• chicken
• poultry
• organ-meats
• meat-and-poultry
• poultry-product
• lead
• cadmium
• chromium

Verification notes

• 2026-05-18 Codex merge-enhance: matched DOI 10.21203/rs.3.rs-4210575/v1 to the already committed source page, added the exact MFK raw handle/path and SHA-256 provenance, changed source_type from peer-reviewed to preprint, expanded routing to existing poultry/organ-meat ingredient pages, and removed overconfident organ-hierarchy claims.
• Source-internal table caution: the visible Table 3.5 Cd block is headed “Deposition of chromium” even though the first column says “Concentration of Cd in Feed”; the visible Cd values place liver above bone at C7 (43.36 vs 20.72 mg/kg dry basis), while the abstract says bone had the highest Cd concentration. This page reports the visible table values and flags the contradiction rather than resolving it silently.
• The Cr organ-deposition block is visible only through C3 in this PDF; the continuation rows for C4-C7 are blank/unreadable. The page therefore does not report high-dose Cr organ-deposition values.
• The matrices: terms use source-specific poultry tissue strings because the common matrix list has no exact poultry-organ terms; sibling meat-source pages already use chicken-muscle and related tissue matrices for edible tissue routing.

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.