Is there mercury in eggs? What consumers need to know about safety

October 4, 2025 •

4 min read

According to a 2023 study published in Consumer health risk assessment of Arsenic and Mercury in hen eggs, the average mercury concentration in hen eggs was reported to be very low, at just 0.18 µg/kg. This information helps address the common question: is there mercury in eggs? While trace amounts of the heavy metal can be present, eggs are not a major source of dietary mercury for most people.

Quick Summary

Trace amounts of mercury can be found in eggs, but levels are generally low and do not pose a health risk to the average consumer. Environmental factors, particularly pollution in specific regions like mining areas, can lead to higher contamination in eggs. The level of mercury in eggs is considerably lower than in most contaminated fish, and risks vary by poultry type and diet. Eggs remain a highly nutritious food source, with potential health impacts from mercury being most relevant in highly localized polluted areas or for sensitive populations.

Key Points

Trace Amounts Exist: Eggs can contain trace levels of mercury, but it is typically not a health risk for the average consumer.
Low Contamination Levels: Multiple studies confirm that mercury concentrations in most commercial hen eggs are very low and well within safety standards.
Source is Environmental: Contamination primarily stems from poultry feed, water, and soil exposed to industrial pollution or natural sources of mercury.
Less Risky Than Fish: Eggs contain significantly less mercury, especially methylmercury, compared to high-trophic-level predatory fish like shark or swordfish.
Location Matters: Free-range poultry in heavily polluted areas, such as near former mining sites, may lay eggs with higher mercury levels than those from controlled farms.
Minimal Risk to Most: For the average consumer, the nutritional benefits of eating eggs far outweigh the negligible risks associated with mercury exposure.
Continuous Monitoring: Food safety authorities and environmental agencies conduct regular monitoring to ensure that heavy metal contamination in the food supply remains at safe levels.

The Trace of Mercury in Eggs

Yes, eggs can contain mercury, but typically only in trace amounts that are not considered a health risk for the average consumer. The presence of mercury in eggs is primarily a result of environmental contamination. As a naturally occurring element, mercury exists in air, water, and soil, from which it can accumulate in the food chain. Poultry can absorb this heavy metal from contaminated feed, water, and soil, which is then transferred to the eggs.

For most people who consume eggs from standard commercial production, the risk is negligible. Regulatory bodies often monitor heavy metal levels in food, and studies consistently show that mercury content in eggs falls within safe limits. High-level contamination is usually localized to specific areas with heavy industrial pollution, such as mining regions.

How Mercury Enters the Food Chain

Mercury can enter the poultry food chain through several pathways, including contaminated feed and environmental exposure. One notable source can be marine-based ingredients, such as fish meal, which is sometimes used in poultry feed. Since fish can accumulate mercury from their aquatic environment, this can transfer to poultry. However, this is tightly regulated, and the resulting mercury levels in commercial eggs are typically minimal.

Environmental factors play a more significant role, especially for free-range poultry. Birds that forage in polluted areas with contaminated soil or water are more susceptible to accumulating heavy metals. For example, a study on duck eggs near a mercury mining area showed significantly higher concentrations of heavy metals compared to eggs from a cleaner background area.

Mercury Levels: Eggs vs. Seafood

When considering dietary sources of mercury, it's essential to put eggs in perspective, especially when compared to fish and other seafood. While seafood is known for its high nutritional value, some types, particularly predatory fish, are also known for higher mercury content due to bioaccumulation up the food chain. Eggs, in contrast, are generally a minimal source. The following table provides a comparison to illustrate this point. Note that the values for eggs are typically far below levels considered risky.


Food Type	Typical Mercury Source	Relative Mercury Level	Risk Profile	Nutritional Benefits
Hen Eggs	Contaminated feed, soil, water	Very low to negligible	Very low for the average consumer. Higher risk only in heavily polluted regions.	High-quality protein, vitamins D and B12, choline, and antioxidants.
Small Fish (e.g., Sardines, Salmon)	Aquatic environment	Low	Low to moderate. Consumption advice exists for sensitive populations like pregnant women and young children.	High in Omega-3 fatty acids, protein, and nutrients.
Large Predatory Fish (e.g., Shark, Swordfish)	Aquatic environment; bioaccumulation	High	High. Consumption warnings advised, especially for sensitive populations.	Excellent source of protein and Omega-3s, but riskier due to high mercury.

The Impact of Rearing and Geography

Research highlights that the type of poultry and their environment can influence mercury concentration in eggs. Ducks, for example, tend to accumulate more heavy metals, including mercury, than chickens because their diet often includes more aquatic life, such as fish and shrimp, which are higher in the food chain. For chickens, the distinction between caged and free-range can also matter, depending on the location.

Caged Poultry: Commercial operations often use controlled, formulated feed, which helps to mitigate the risk of heavy metal contamination from environmental factors.
Free-Range Poultry: In most typical agricultural settings, free-range chicken eggs have very low mercury levels, comparable to caged eggs. However, if the free-range birds live near a site with high environmental pollution, like a former mining area, their risk of exposure is higher due to foraging in the surrounding soil.

Are Eggs Still Safe to Eat?

Despite the potential for trace amounts of mercury, eggs remain a safe and healthy food for the vast majority of people. The levels found in most commercial eggs are well below any amount that would be considered a health concern. The health benefits of eggs, including their richness in protein, vitamins, and minerals, far outweigh the minimal risk posed by mercury in typical dietary consumption. Regular monitoring of poultry feed and environmental conditions by food safety authorities helps ensure that contamination remains at low, non-harmful levels.

Conclusion

While it is technically possible for there to be mercury in eggs due to environmental factors, extensive research indicates that the levels in most commercially and ethically produced eggs are low enough not to pose a significant health risk to consumers. Unlike certain types of predatory fish, eggs are not a primary source of concern for dietary mercury exposure. The rare instances of elevated mercury typically occur in localized areas with specific environmental contamination, like mining sites, affecting some free-range poultry more than commercially raised chickens. Consumers can continue to enjoy eggs as a nutritious part of a balanced diet with high confidence in their safety.

Frequently Asked Questions

No, it is technically possible for eggs to contain trace amounts of mercury, as it is a naturally occurring element in the environment. However, for most commercially produced eggs, the levels are consistently very low and not considered a health concern.

Chickens can absorb mercury from contaminated sources in their environment, such as polluted soil or water, or from their feed if it contains contaminated ingredients like fish meal. The mercury then bioaccumulates in their bodies and can be transferred to the eggs.

Not necessarily. The risk depends more on the specific environment. While free-range chickens have more exposure to soil, those in unpolluted areas typically have low mercury levels. However, free-range birds in highly contaminated areas (e.g., near industrial sites) could have higher levels than caged birds on controlled, monitored feed.

Yes, studies have shown that waterfowl like ducks can accumulate higher levels of heavy metals, including mercury, in their eggs. This is because their diet often includes more aquatic life, which can contain higher concentrations of mercury than the typical feed for land-based chickens.

Compared to many types of fish, especially larger predatory species, eggs have significantly lower levels of mercury. Fish and shellfish are the most common sources of dietary methylmercury exposure for humans.

It is unlikely for any food product to have zero environmental contaminants, including mercury, but commercially available eggs are produced under strict food safety guidelines. While one brand may have slightly lower levels than another, the difference for general consumers is not significant, and all are typically within safe limits.

No, major health organizations typically focus their mercury warnings on certain types of fish and seafood, particularly for vulnerable populations like pregnant women and young children. The mercury levels in eggs from most sources are not high enough to warrant specific warnings or dietary restrictions.