Overview
Zhang et al. (2022) assessed lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) contamination in Chinese pork using 126 previously published concentration records collected from CNKI. The routeable product values are the paper’s fitted pork-concentration summaries in mg kg-1; individual pork sample records are not reproduced in the extracted PDF text. Arsenic and mercury are treated here as total-element context (tAs, tHg) because the paper does not report inorganic arsenic or methylmercury speciation.
Key numbers
The paper reports the concentration-record panel as 42 Pb, 36 Cd, 22 Hg, and 26 As records, for 126 records total. The authors fitted concentration distributions about 10,000 times and reported the resulting pork concentrations in mg kg-1.
| Analyte label used here | Source label | Source-fitted concentration in pork | Source-listed Chinese residue limit | Single pollution index (Pi) | Source classification |
|---|---|---|---|---|---|
| lead (Pb) | Pb | 6.4 x 10^-2 mg kg-1 | 0.2 mg/kg | 0.318 | Safe |
| total arsenic (tAs) | As | 2.8 x 10^-2 mg kg-1 | 0.5 mg/kg | 0.114 | Safe |
| cadmium (Cd) | Cd | 1.2 x 10^-2 mg kg-1 | 0.1 mg/kg | 0.146 | Safe |
| total mercury (tHg) | Hg | 0.7 x 10^-2 mg kg-1 | 0.05 mg/kg | 0.053 | Safe |
Table 3 reports non-carcinogenic THQ values by age and sex. The largest total THQ values were in the [2,4) age group: male TTHQ 0.797 and female TTHQ 0.745. The table’s total row reports THQ values of Pb 0.198, As 0.143, Hg 0.111, and Cd 0.018, with total TTHQ 0.470.
The source reports contribution rates to TTHQ of Pb 42.2%, As 30.4%, Hg 23.6%, and Cd 3.8%. For carcinogenic risk, the paper states that ILCR followed As > Cd > Pb for the same age group and that the ILCR of As in the [2,4] age group exceeded 1 x 10^-4; no exact numeric ILCR table is extractable from the text layer beyond the plotted figure.
The fault-tree section uses a 2011 Nanjing Farmers Market lead-exceedance case as an example. It describes feed heavy metals exceeding standards, insufficient qualification inspection, processing-enterprise traceability limits, and overlapping regulatory supervision as supply-chain context; those case details are not additional pork occurrence values.
Methods (brief)
The authors collected previously published pork heavy-metal concentration data from www.cnki.net and combined the concentration panel with Chinese body-weight and pork-intake data from national nutrition and health monitoring reports. They evaluated Pb, As, Cd, and Hg with a single pollution index, estimated daily intake, target hazard quotient, incremental lifetime cancer risk, and fault-tree analysis. The paper states that reagent blanks were used to correct analytical values and that standard reference materials from the National Research Center of Certified Reference Materials were within +/- 10 percent of certified values for all target metals, but the source page should still treat the occurrence dataset as secondary because the authors did not newly sample pork in this paper.
Related evidence
Update history
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