Heavy metals measured in four varieties of Thai rice
What it found
Levels of eight heavy metals were measured in 55 samples of Thai rice.
Estimated cancer risks from eating this rice over a lifetime ranged from 5 in 10,000 to 3 in 1000.
What they found
Studies in people
Non-cancer risk thresholds
For most rice types, estimated non-cancer risks stayed below the safety limit of 1. Manganese in Pka Am Pun rice and arsenic in three varieties went above that limit.
Combined metal exposure
When all metals were added together, only one sticky rice variety stayed below the combined risk limit of 1. The other varieties went above it.
Lifetime cancer estimates
The authors calculated the chance of developing cancer over a lifetime of eating this rice. The estimates ranged from 5 in 10,000 to 3 in 1000.
Other findings
Metals measured in rice
Researchers measured chromium, manganese, cobalt, nickel, copper, zinc, arsenic and cadmium in 55 rice samples. The samples covered four local Thai varieties.
What the authors conclude
- They found that most individual heavy metals in the rice stayed below non-cancer risk limits, except for manganese and arsenic in certain varieties.
- Their calculations suggest that eating these rice types over a lifetime carries a small but measurable chance of cancer.
- They note that only one sticky rice variety kept the combined metal risk below the threshold of 1.
How it was done
People in Thailand eat local rice that may contain heavy metals. The authors wanted to estimate the health risks for different age and gender groups.
They tested 55 samples of Thai rice across four varieties for eight heavy metals using a lab technique called ICP-MS. They then used a probability-based method to estimate health risks for Thai people of different ages and genders.
What it can’t tell you
- We summarised it from the abstract only.
- These are estimates based on measuring metals in rice, not a study following real people over time.
- They cannot prove that eating this rice will cause cancer or other illness in any individual person.
Who paid
- Conflicts
- Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Authors work at
- Thailand Institute of Nuclear Technology (Public Organization), Thailand; Bangkokthonburi University, Thailand; Srinakharinwirot University, Thailand
The paper
- Title
- Heavy metals and probabilistic risk assessment via rice consumption in Thailand
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Kukusamude C, Sricharoen P, Limchoowong N, Kongsri S (2021). Heavy metals and probabilistic risk assessment via rice consumption in Thailand. Food chemistry. doi:10.1016/j.foodchem.2020.127402PubMed 32711260DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error