Does salmon have a lot of metal in it? The definitive guide to salmon and heavy metals

November 14, 2025 •

3 min read

According to the FDA, fresh and frozen salmon have a very low mercury content at just 0.022 ppm, but many people still wonder: does salmon have a lot of metal in it, and is it a health concern? For most consumers, the answer is that salmon is a safe and healthy option, with contamination levels well below established safety guidelines.

Quick Summary

Salmon is considered a low-mercury fish by food safety agencies, with levels well below regulatory limits for regular consumption. While small amounts of heavy metals like mercury and arsenic are present, they do not typically pose a health risk to the average consumer. Metal concentrations can vary between wild and farmed salmon, though both are safe choices.

Key Points

Low Mercury Content: Salmon is considered a low-mercury fish, especially compared to larger predatory species like swordfish and tuna.
Arsenic Form: The arsenic found in salmon is mainly the non-toxic organic form, arsenobetaine, which is not harmful to humans.
Safe Consumption Levels: Regulatory bodies like the FDA and EU have determined that metal levels in both farmed and wild salmon are well within safe consumption limits.
Wild vs. Farmed Differences: Farmed salmon often has lower mercury levels than wild salmon, though wild salmon may have different levels of other metals like cadmium.
Focus on Health Benefits: The high content of omega-3 fatty acids in salmon makes it a highly beneficial food, with health risks from metal contamination considered negligible for most people.
Informed Choices: Varying your seafood intake and following official consumption guidelines are the best ways to minimize any potential exposure.

Understanding Heavy Metals in Fish

Heavy metals, like mercury and arsenic, are naturally occurring elements that can accumulate in the aquatic environment and subsequently in fish. However, not all heavy metals are created equal, and their toxicity depends on several factors, including the chemical form and concentration. The good news is that most commercially sold salmon contains levels of these metals that are considered safe for consumption.

The Mercury Concern

Mercury in fish primarily exists as methylmercury, a highly toxic organic form. The levels of methylmercury in fish are influenced by the fish's position in the food chain, its lifespan, and the water quality of its habitat. Larger, longer-lived predatory fish like swordfish and certain tuna species tend to accumulate higher levels of mercury because they consume smaller fish that also contain mercury. Salmon, being lower on the food chain and having a shorter lifespan than these larger predators, generally has much lower mercury levels, making it a safer choice.

Arsenic and Other Metals

Arsenic is another metal found in seafood, but again, its form is critical. In marine fish, the arsenic is predominantly present as arsenobetaine, an organic form considered non-toxic to humans. While studies have shown that organic arsenic can be higher in farmed salmon compared to wild salmon, this is not considered a health risk. Other heavy metals like lead and cadmium are typically found at very low or undetectable levels in salmon muscle tissue. Essential trace minerals, such as copper and zinc, may also be present, often originating from fish feed, but are not usually a toxicological concern.

Comparing Wild vs. Farmed Salmon

One of the most common debates revolves around whether wild or farmed salmon is safer in terms of metal contamination. Research indicates that both are safe options, but with some notable differences in their metal profiles.

Wild vs. Farmed Salmon: Metal Content Comparison


Feature	Wild Salmon	Farmed Salmon
Mercury	Generally has slightly higher levels than farmed salmon, but still low.	Typically has lower levels than wild salmon.
Organic Arsenic	Lower levels of the non-toxic organic form.	Sometimes higher levels of the non-toxic organic form.
Cadmium	May have higher concentrations depending on the species and region.	Usually very low, often near detection limits.
Lead	Very low levels generally reported.	Very low levels and often below regulatory limits.
Contaminant Risk	Health risk is minimal due to low heavy metal bioaccumulation.	Health risk is minimal, with levels well below international standards.

How to Minimize Potential Exposure

For those who wish to be extra cautious, here are some practical steps to minimize any potential heavy metal exposure from fish:

Vary your diet: Don't rely solely on fish for protein. Incorporate other sources like poultry, legumes, and lean meats.
Choose smaller, low-mercury fish: Species like sardines, anchovies, and cod have very low mercury levels.
Limit consumption of large, predatory fish: Minimize your intake of high-mercury fish like swordfish, shark, and king mackerel.
Select your salmon wisely: Consider sourcing your salmon from regions known for cleaner waters, such as wild Alaskan salmon.
Follow official guidelines: Adhere to consumption advisories, especially if you are pregnant, nursing, or feeding young children.

Consumption Guidelines and Health Benefits

It's important to remember that the health benefits of eating salmon—particularly its high omega-3 fatty acid content—are significant. Organizations like the FDA recommend eating two to three servings of low-mercury seafood per week for these benefits. For pregnant or breastfeeding women and young children, the omega-3s are crucial for brain and vision development. The key is to make informed choices and focus on low-mercury options like salmon. The occasional serving of higher-mercury fish is unlikely to be harmful, but moderation is advised, particularly for sensitive populations.

For more detailed information on which fish are best choices for consumption, you can refer to the official U.S. Food and Drug Administration guidelines.

Conclusion

In summary, while salmon, like all fish, does contain trace amounts of heavy metals, it is not considered to have a lot of metal in it compared to larger predatory species. The levels found in both wild and farmed salmon are generally well below safety thresholds and do not pose a significant health risk for the majority of consumers. By making mindful choices, such as eating a variety of seafood and limiting consumption of high-mercury species, you can enjoy the considerable health benefits of salmon without worry.

Frequently Asked Questions

No, salmon is considered a low-mercury fish. Its mercury content is significantly lower than that of larger predatory fish like swordfish, king mackerel, and ahi tuna, making it a safe choice for regular consumption.

Studies show that farmed salmon generally has lower levels of mercury, cadmium, and lead than wild salmon, though it can have higher levels of the non-toxic organic arsenic. Both are considered safe to eat regarding heavy metals.

No, the vast majority of arsenic in marine seafood like salmon is in the form of arsenobetaine, which is non-toxic to humans. This organic form of arsenic is treated differently from the inorganic, more harmful form found in water.

While salmon is safe, pregnant and nursing women, as well as young children, are typically advised to be more cautious about overall fish consumption and to prioritize low-mercury options. These groups stand to benefit most from salmon's omega-3s.

Wild Alaskan salmon is frequently cited as one of the cleanest and healthiest options, with low levels of contaminants. Both wild and farmed salmon are generally considered safe choices with low mercury levels.

Consuming excessive amounts of high-mercury fish over a long period could pose health risks, particularly affecting the nervous system. However, the low levels in salmon mean it can be part of a healthy diet without worry.

Salmon is an excellent source of healthy omega-3 fatty acids (EPA and DHA), which are beneficial for cardiovascular health, brain development, and vision. These benefits often outweigh the minimal risk from contaminants for most people.