Heavy metals in Thai rice and health risk estimates
What it found
In 55 samples of Thai local rice, most heavy metal levels were below the safety threshold, but some varieties exceeded it for manganese and arsenic.
The authors estimate up to 3 in 1000 chances of developing cancer over a lifetime of eating this rice.
What they found
Metals measured
The researchers measured eight heavy metals in 55 rice samples from four local Thai varieties.
Non-cancer risk
For most rice varieties, the hazard quotient for non-cancer risks was below the threshold of 1. But it was above 1 for manganese in Pka Am Pun rice and for arsenic in Pka Am Pun, Jek Chuey Sao Hai, and Leb Nok rice.
Overall risk
Only the hazard index for Khaowong Kalasin sticky rice was below 1.
Cancer risk
The highest estimated cancer risk over a lifetime of eating Thai local rice ranged from 5 in 10,000 to 3 in 1000 chances of developing cancer.
What the authors conclude
- They report that the hazard quotient for non-carcinogenic risks was below the threshold limit of 1 for all rice varieties except Mn in Pka Am Pun rice and As in Pka Am Pun rice, Jek Chuey Sao Hai rice, and Leb Nok rice.
- They note that only the hazard index for consumption of Khaowong Kalasin sticky rice was below 1.
- They estimate that the maximum cancer probabilities over the lifetime consumption of Thai local rice were in the range of 5 in 10,000 to 3 in 1000 chances in developing cancer.
How it was done
They measured heavy metals including Cr, Mn, Co, Ni, Cu, Zn, As, and Cd in 55 samples of Thai local rice from 4 varieties. They then estimated health risks for different Thai population groups by age and gender using a probabilistic approach.
What it can’t tell you
- We summarised it from the abstract only.
- This study measured heavy metals in rice samples and estimated risks. It did not follow people over time to see if they actually developed health problems.
- The risk estimates are based on assumptions about how much rice people eat and for how long. They cannot prove that eating this rice causes cancer or other illnesses.
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
- 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 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error