Heavy metals in wheat flour grown near lead smelting
What it found
Wheat flour grown in a lead-smelting area contained cadmium, copper, lead and zinc, and the authors say eating it may raise health concerns, especially for children.
The work is based on measured metal levels and risk calculations, not on people.
What they found
Metals in whole wheat flour
Whole wheat flour contained on average 0.38 mg/kg cadmium, 3.83 mg/kg copper, 0.48 mg/kg lead and 29.3 mg/kg zinc.
Metals in white flour
Levels in wheat flour were only slightly lower than in whole wheat flour.
Daily dose ratios
The ratio between the average daily dose from whole wheat flour and from wheat flour ranged from 1.06 to 3.76, with lead showing the highest values.
Risk for children
For children, the average hazard quotients for whole wheat flour were 4.19 for cadmium, 1.06 for copper, 1.53 for lead and 1.07 for zinc. For wheat flour they were 3.81, 0.68, 0.70 and 0.98.
Risk for adults
The hazard quotients for adults were lower than those for children.
Lead risk reduced
When wheat flour rather than whole wheat flour is eaten, only the human health risk from taking in lead is reduced.
What the authors conclude
“Overall results indicated that consumption of wheat products may lead to health concerns in the heavy metal contaminated area, yet when wheat flour rather than whole wheat flour is consumed, only the human health risk from Pb ingestion is reduced.”
Also in their conclusions
- They say that eating wheat products may lead to health concerns in the heavy metal contaminated area.
- They advise that altering or removing human edible crops in the most contaminated areas should be considered.
How it was done
Wheat flour is a major source of metals taken in by people, especially when the wheat is grown in soil contaminated with metals.
The authors measured cadmium, copper, lead and zinc in whole wheat flour, wheat flour and wheat bran grown in an area polluted by lead smelting. They then assessed the cancer and non-cancer risks from eating these products.
What it can’t tell you
- We summarised it from the abstract only.
- This work measured metals in flour and calculated risks. It did not follow people to see whether they became ill.
- The risk calculations are based on average daily doses and hazard quotients, not on actual health outcomes.
Who paid
- Funding
- Funded by The National Key Research and Development Programs of China; National Natural Science Foundation of China (from the PubMed record).
- Authors work at
- School of the Environment, China; Yantai Institute of Coastal Zone Research, China
The paper
- Title
- Lead smelting alters wheat flour heavy metal concentrations and health risks
- Type
- Study
- Summarised from
- Abstract only
- Cite
- Li L, Zhang Y, Ippolito JA, Xing W, Tu C (2021). Lead smelting alters wheat flour heavy metal concentrations and health risks. Journal of environmental quality. doi:10.1002/jeq2.20198PubMed 33462853DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error