What heavy metals does rice contain? Key Facts and Mitigation

November 24, 2025 •

4 min read

According to a 2025 study by Healthy Babies Bright Futures, all samples of store-bought rice tested were found to contain toxic heavy metals, most notably arsenic and cadmium. The presence of these contaminants in rice is a significant public health concern due to rice's role as a dietary staple for billions of people worldwide.

Quick Summary

Rice can accumulate heavy metals like arsenic, cadmium, lead, and mercury from its environment. This occurs because the rice plant efficiently absorbs these elements from contaminated soil and irrigation water. The level of contamination varies by rice type and its region of origin, posing potential health risks, particularly for chronic consumers and vulnerable populations like children.

Key Points

Arsenic and Cadmium are Key Contaminants: Rice is particularly prone to absorbing arsenic and cadmium from soil and water, posing health risks with chronic exposure.
Source and Type Matter: Heavy metal levels in rice vary by its geographic origin, soil quality, and type. Brown rice generally has higher levels than white rice due to contaminants in the outer bran layer.
Mitigate with Cooking: Specific cooking methods, like cooking rice in a high water-to-rice ratio or using the 'parboiling with absorption' technique, can significantly reduce inorganic arsenic content.
Diversity is Key to Safety: Reducing reliance on rice as a single staple and incorporating other grains like quinoa, barley, and farro can lower overall heavy metal intake.
Risk is Cumulative: The primary risk comes from long-term, high-volume consumption. Vulnerable populations, like children, are at higher risk.

Why Does Rice Absorb Heavy Metals?

Rice, a semiaquatic plant, is uniquely susceptible to heavy metal contamination because it is typically grown in flooded paddy fields. This flooded environment, coupled with soil composition, dictates the bioavailability of certain metals, which the plant's root system then readily absorbs.

The Key Contaminants Found in Rice

Arsenic (As): The most prevalent heavy metal in rice, inorganic arsenic, is a known carcinogen. It enters the plant through the same pathways used to absorb vital nutrients like silicon and phosphate. Floodwater containing arsenic-contaminated groundwater is a major source, especially in Southeast Asia.
Cadmium (Cd): This toxic metal easily accumulates in the rice grain and has been linked to kidney damage, weakened bones, and cancer. The bioavailability of cadmium is highly dependent on soil pH, with acidic soils promoting greater uptake by the rice plant. Industrial waste and phosphate fertilizers are common sources of soil cadmium contamination.
Lead (Pb): While generally absorbed by rice in lower quantities than arsenic and cadmium, lead contamination is still a concern, especially in areas with industrial pollution. It accumulates most heavily in the rice roots, but can still be transported to the grain.
Mercury (Hg): The presence of mercury in rice is a documented risk, although the concentrations vary significantly by region and source of contamination, such as industrial waste. Methylmercury is a particularly toxic form that can accumulate in the rice grain.

Factors Influencing Heavy Metal Levels

Numerous factors determine the concentration of heavy metals in a bag of rice. These include:

Soil and Water: The primary source of heavy metal contamination is the soil and water where the rice is grown. Industrial discharges, mining runoff, and the use of certain pesticides and fertilizers contribute significantly.
Rice Variety: Certain types of rice accumulate more heavy metals than others. For example, brown rice often has higher levels of heavy metals than white rice because the contaminants are concentrated in the outer bran layer, which is removed during the milling process for white rice.
Geographic Origin: The region where rice is cultivated plays a critical role due to varying geological and industrial conditions. Rice from different parts of the world, and even different regions within a single country, can have vastly different heavy metal profiles.
Agricultural Practices: The way rice is farmed, including water management, can influence metal uptake. Continuously flooded paddies, for instance, can lead to higher arsenic accumulation but lower cadmium levels, compared to intermittently flooded fields.

Comparison of Heavy Metal Content in Rice Varieties and Alternatives


Grain Type	Typical Heavy Metal Content	Health Considerations	Recommended Consumption
Brown Rice	Generally higher heavy metal levels, particularly arsenic and cadmium, as contaminants concentrate in the bran.	Higher fiber and nutrient content, but greater heavy metal load may pose a risk with frequent, high-volume consumption.	Best consumed in moderation. Cooking methods can significantly reduce heavy metal levels.
White Rice	Lower levels of heavy metals compared to brown rice due to the removal of the outer bran layer during processing.	Less nutritional value (fiber, nutrients) than brown rice, but also carries a lower heavy metal load.	A potentially safer option for frequent consumption, especially from lower-risk regions.
Basmati Rice (from certain regions)	Indian Basmati and Thai Jasmine rice often have some of the lowest levels of heavy metals among rice varieties. However, some reports indicate higher cadmium in Indian basmati varieties.	A good choice for reducing exposure, but vigilance is advised regarding the specific origin and brand.	Preferred choice for reducing arsenic exposure, especially from reputable sources.
Rice Alternatives (e.g., Quinoa, Farro)	Generally much lower concentrations of heavy metals like arsenic and cadmium than rice.	Provide excellent nutritional variety and are a great way to reduce overall heavy metal exposure from grains.	Excellent for diversifying the diet to minimize reliance on rice as a sole staple.

How to Reduce Heavy Metal Exposure from Rice

While eliminating heavy metal exposure completely is difficult, several cooking methods can significantly reduce the amount of contaminants in your rice.

Parboiling with Absorption (PBA): This method involves boiling rice in a large volume of pre-boiled water for five minutes before draining. Then, refresh the water and cook the rice until the water is absorbed. This can remove a large portion of arsenic while retaining nutrients.
Using Excess Water: Cooking rice in a large water-to-rice ratio (e.g., 6-10 parts water to 1 part rice), similar to cooking pasta, can reduce inorganic arsenic levels by up to 60%. The water should be drained before serving.
Soaking: Soaking rice overnight before cooking and draining can reduce arsenic levels significantly. Rinsing rice alone is not as effective.
Diversify Your Diet: The most effective strategy is not to rely on rice as a primary staple. Include a variety of other grains with lower heavy metal profiles, such as quinoa, barley, farro, and couscous.

Conclusion

The presence of heavy metals, particularly arsenic and cadmium, in rice is a well-documented issue with potential health implications, especially for those consuming large quantities or from high-risk regions. However, this issue does not mean rice must be eliminated from your diet. By understanding the factors that influence contamination, making informed choices about the type and origin of rice, and employing specific cooking methods to reduce contaminant levels, consumers can significantly mitigate their exposure. Diversifying one's diet with lower-risk grain alternatives is another crucial strategy for managing this public health concern, ensuring that rice remains a safe component of a balanced diet.

Learn more about food contaminants from the FDA.

Frequently Asked Questions

The primary heavy metal found in rice is arsenic, specifically the more toxic inorganic form. It is efficiently absorbed by the rice plant from contaminated soil and irrigation water during growth.

Yes, brown rice typically contains higher levels of heavy metals like arsenic and cadmium than white rice. This is because these contaminants tend to accumulate in the outer bran layer, which is removed during the milling process to produce white rice.

While rinsing can remove some heavy metals, it is not highly effective. More effective methods involve cooking the rice with excess water and draining it, or soaking the rice overnight before cooking.

Certain varieties tend to have lower heavy metal levels. Some studies suggest that basmati rice from India and Thai jasmine rice, along with California-grown sushi rice, have lower concentrations. However, sources and testing may vary.

Chronic exposure to heavy metals in rice has been linked to increased cancer risk, particularly from inorganic arsenic. Cadmium exposure can also cause kidney and bone damage. Vulnerable populations like children and pregnant women face heightened risks.

Excellent grain alternatives with lower heavy metal levels include quinoa, barley, farro, millet, and couscous. Diversifying your grain intake is a key strategy for reducing overall exposure.

Rice is uniquely susceptible because it's often grown in flooded paddy fields, which increases the bioavailability of certain metals, particularly arsenic. Other grains like wheat and barley are typically grown in drier conditions and absorb less of these contaminants.