What Are the Heavy Metals in Rice?

November 10, 2025 •

4 min read

According to a 2025 report by Healthy Babies Bright Futures, 100% of the rice samples they tested contained some levels of arsenic, a key heavy metal found in rice. Understanding which heavy metals are present and why rice is susceptible to contamination is crucial for making informed dietary choices.

Quick Summary

This article examines the primary heavy metals found in rice, including arsenic, cadmium, and lead, outlining their sources and the associated health concerns. We provide actionable advice on how to reduce exposure through cooking techniques and selecting specific rice varieties.

Key Points

Arsenic is a primary contaminant: Rice absorbs significant amounts of inorganic arsenic, a known carcinogen, from flooded soil and water.
Cadmium and lead pose health risks: Cadmium is associated with kidney damage, while lead can cause neurological harm, especially in children.
Brown rice typically contains more heavy metals: Due to their concentration in the outer bran layer, heavy metals are more prevalent in brown rice than in polished white rice.
Cooking method dramatically reduces heavy metals: Soaking rice and cooking it in a high volume of excess water (like pasta) and then draining it can remove up to 60% of the heavy metal content.
Origin matters: Rice from different regions varies in heavy metal content, with California-grown, Indian Basmati, and Thai Jasmine varieties often having lower levels compared to rice from the Southeast U.S..
Dietary diversity is key: Integrating other grains like quinoa, millet, and barley into your diet helps reduce overall heavy metal exposure from rice consumption.

Key Heavy Metals Found in Rice

Rice, a staple food for a large portion of the world's population, is known to accumulate more heavy metals than other cereal crops. The primary culprits found in rice include arsenic, cadmium, and lead, with mercury also present in some regions.

Arsenic (As)

Arsenic is arguably the most publicized heavy metal in rice, and for good reason. Rice absorbs significantly more arsenic from its environment than most other plants. The inorganic form of arsenic is the more toxic variety and is naturally occurring in soil and groundwater, but its levels have increased due to industrial pollution and pesticide use. It is a known human carcinogen, and long-term exposure is linked to various health problems. Brown rice, in particular, tends to have higher arsenic levels because the heavy metal accumulates in the outer bran layer, which is removed to make white rice.

Cadmium (Cd)

Cadmium is another dangerous heavy metal found in rice, entering the food chain through contaminated soil, fertilizers, and industrial waste. Chronic exposure to cadmium can lead to severe health issues, including kidney damage, bone disease (like the infamous Itai-itai disease in Japan), and an increased risk of cancer. Like arsenic, the concentration of cadmium in rice can vary depending on where and how it is grown.

Lead (Pb)

While typically at lower concentrations than arsenic, lead can also be present in rice. Lead exposure is particularly harmful to children, affecting neurodevelopment and potentially causing IQ loss. Industrial emissions, vehicle exhaust in the past, and contaminated water are common sources of lead pollution.

Mercury (Hg)

In certain areas, especially near historical mercury mining sites, rice can accumulate mercury, primarily the neurotoxin methylmercury. Although fish is the most common source of mercury exposure for humans, rice can be a significant pathway in inland areas where fish consumption is low.

Why and How Does Rice Absorb Heavy Metals?

Rice's unique cultivation method in flooded paddy fields makes it particularly vulnerable to heavy metal uptake. This differs significantly from other cereal crops like wheat and barley, which are typically grown in drier soil.

Paddy Field Conditions

Flooded Conditions: Growing rice in flooded fields creates anaerobic (oxygen-free) conditions that change the chemical form of heavy metals in the soil, making them more bioavailable for absorption by the rice plant. Arsenic, for instance, is more readily absorbed by rice roots in its soluble form (arsenite).
Efficient Absorption: Rice plants are highly efficient at absorbing water from the soil, and with it, any dissolved heavy metals. This is a natural consequence of their growth environment.
Nutrient Competitors: Some heavy metals are absorbed by the same transporters used for essential nutrients. For example, the same transport proteins that take up silicates (a nutrient) also take up arsenites.

Reducing Heavy Metals Through Cooking and Variety Choice

Consumers can take several steps to minimize their heavy metal intake from rice without eliminating it from their diet entirely.

Methods for Reducing Heavy Metals

Wash Thoroughly: Rinse the rice thoroughly before cooking. This can remove a portion of the heavy metals, though it is less effective than cooking with excess water.
Use Excess Water (like pasta): Cooking rice with a high water-to-rice ratio (e.g., 6 to 10 parts water to 1 part rice) and then draining the excess water afterward can significantly reduce inorganic arsenic levels, by up to 60%.
Soak Overnight: Soaking rice overnight, draining the water, and then cooking it with a fresh batch of excess water further maximizes the removal of heavy metals by opening up the grain and allowing more of the contaminants to escape.
Alternate Grains: To reduce overall exposure, consider incorporating other grains like quinoa, millet, and barley into your diet.

Comparison of Rice Varieties

Contamination levels vary by rice type and where it's grown. This table compares some common types based on typical heavy metal tendencies, particularly for arsenic and cadmium.


Rice Variety	Typical Contamination Level (Arsenic/Cadmium)	Rationale	Best for Reducing Exposure?
Brown Rice	Higher	Heavy metals concentrate in the bran layer, which remains intact.	No (but contains more nutrients like magnesium).
White Rice (Polished)	Lower	Polishing removes the outer bran layer where many heavy metals are concentrated.	Yes (with trade-offs in nutrient loss).
California-Grown Rice	Lower	Agricultural practices and cleaner water sources in this region result in lower overall contamination.	Yes
Thai Jasmine/Indian Basmati	Lower	Often grown in conditions with naturally lower environmental heavy metal levels.	Yes
Arborio/Southeast US Rice	Higher	Growing conditions in the Southeast US, and the specific variety (Arborio), have been linked to higher heavy metal content.	No

The Role of Soil and Water Contamination

Ultimately, the concentration of heavy metals in rice begins with the environment it's grown in. Sources of contamination include:

Industrial and Mining Activities: Waste and emissions from industrial sites and mining operations can release heavy metals into the air, soil, and water. These areas are often hotspots for contaminated rice.
Agricultural Practices: The use of contaminated irrigation water and certain phosphate fertilizers that naturally contain heavy metals can contribute to accumulation in the soil over time.
Natural Soil Composition: The geological makeup of the soil can also have a significant impact. Some regions have higher natural background levels of heavy metals.

Conclusion

While a common dietary staple, rice can contain concerning levels of heavy metals like arsenic and cadmium, posing potential health risks, especially for vulnerable populations such as children. Factors like the type of rice (brown often has more than white) and the region it was grown dramatically influence contamination levels. Fortunately, simple and effective cooking methods, including soaking and boiling rice in excess water, can substantially reduce these heavy metal levels. By diversifying your grain consumption and adopting these safe preparation techniques, you can continue to enjoy rice as part of a healthy, balanced diet while minimizing your exposure to harmful contaminants. For more on dietary adjustments, consult a reliable health source. Learn more about reducing heavy metal exposure via diet on Healthline.

Frequently Asked Questions

White rice, especially varieties like California-grown rice, Indian basmati, and Thai jasmine, generally have lower levels of heavy metals compared to brown rice, which retains more contaminants in its bran layer.

Yes. Cooking rice in excess water, similar to pasta, and draining the leftover water can reduce inorganic arsenic levels by a significant amount. Pre-soaking the rice overnight can further increase the removal rate.

For most people, brown rice is safe to consume in moderation as part of a varied diet. However, for those with a high-rice diet, cooking methods that reduce heavy metals are recommended. The choice should also balance the higher heavy metal risk against the nutritional benefits of brown rice.

Yes, children and infants are considered more vulnerable to heavy metal exposure due to their smaller body size and developing neurological systems. Regulatory agencies often set stricter limits for rice products marketed toward infants, and using rice drinks for toddlers is discouraged.

Rinsing rice can remove some heavy metals from the surface, but it is much less effective than cooking rice in a large volume of water that is later drained. Soaking is generally a more effective pre-cooking step.

No. Arsenic and other heavy metals are naturally present in the soil and water. The 'organic' designation refers to the farming practices used, not the contaminant levels present in the environment where the rice is grown.

Arsenic is the most common heavy metal in rice, with inorganic arsenic being the most toxic form. It accumulates in rice due to the flooded conditions of paddy fields.