Overview
The authors analyzed about half a million cadmium results for rice, wheat flour and other processed grain products from China’s national food safety sampling system for 2023 and 2024. They summarize cadmium by province and product, compute pollution and health risk indices, and group city and product combinations into five risk levels with a k-means++ clustering method. Rice and southern provinces carried the highest cadmium.
Key numbers
- National means: rice 0.04887 (SD 0.06798), wheat flour 0.01369 (SD 0.01161), other processed grain products 0.01590 (SD 0.04380) mg/kg (Table 1).
- Highest rice means: Jiangxi 0.11262, Hunan 0.10986, Guangxi 0.09311 mg/kg (Table 1).
- Wheat flour means ranged from 0.00656 (Heilongjiang) to 0.02267 mg/kg (Henan) (Table 1).
Methods (brief)
Secondary analysis of official inspection results; analytical methods and detection limits are not described. Non-detects were set to zero and values reported with ”<” were kept at their numeric value before computing means. Risk indices (NIPI, THQ, TCR) used consumption data from the fifth China Total Diet Study.
Evidence Fitness
Very large, nationally representative monitoring dataset, but with no method or detection-limit detail and per-province sample counts not printed. Zero substitution for non-detects lowers the means. Wheat flour is a proxy for cream of wheat (farina), which is not measured, so the cream-of-wheat page is not linked.