Wild salmon is one of the safest fish you can eat. It carries some of the lowest mercury levels of any commercially available seafood, and both U.S. federal agencies that oversee food safety place it in the “Best Choices” category for all ages, including pregnant women and young children. That said, there are a few real considerations worth understanding, from parasites in raw preparations to trace contaminants in the environment.
Mercury Levels Are Extremely Low
Mercury is the contaminant most people worry about in fish, and wild salmon barely registers. Fresh or frozen salmon averages just 0.022 parts per million (ppm) of mercury, with a maximum recorded level of 0.19 ppm. For comparison, swordfish averages around 0.995 ppm and bigeye tuna about 0.689 ppm. Salmon contains roughly 30 to 45 times less mercury than the fish that land on federal “avoid” lists.
Canned salmon is even lower, averaging 0.014 ppm. These numbers are well below the threshold that would prompt any consumption limit for healthy adults. You could eat wild salmon every day of the week and still fall far short of mercury intake levels associated with health effects.
PCBs, Heavy Metals, and Other Pollutants
Early studies raised alarms about PCBs (industrial chemicals that persist in the environment) in salmon, particularly farmed varieties. Follow-up research has largely put those concerns to rest. The Washington State Department of Health reviewed the evidence and concluded that both wild and farmed salmon have low levels of mercury, PCBs, and other contaminants, and that the scientific consensus considers both safe to eat.
Other heavy metals like lead and cadmium show up at very low, comparable levels in both wild and farmed salmon. Persistent organic pollutants, including certain pesticide residues, are similarly low. Wild salmon actually tends to have slightly higher levels of some of these compounds than farmed salmon, since wild fish accumulate whatever is in their natural food chain, but in both cases the amounts are small enough that health agencies don’t flag them as a concern.
Microplastics: A Real but Small Concern
Microplastics are now found in virtually all seafood, and wild salmon is no exception. Research on juvenile Chinook salmon off Vancouver Island found an average of about 1.2 microplastic particles per fish, mostly tiny fibers. The researchers concluded these levels were relatively low and unlikely to represent an immediate threat. The bigger unknown involves particles smaller than 100 micrometers, which are harder to study and may be able to pass through tissues more easily. This is a concern that applies to all seafood and even tap water, not something unique to salmon.
Safety During Pregnancy and for Children
The joint EPA and FDA advisory on fish consumption places salmon squarely on the “Best Choices” list. Pregnant and breastfeeding women are advised to eat 8 to 12 ounces of low-mercury seafood per week, and salmon is specifically named as one of the recommended options. Children can safely eat two servings per week from the same list.
This recommendation exists because the nutritional benefits of salmon for fetal and child brain development (it’s one of the richest sources of omega-3 fatty acids) outweigh the negligible mercury exposure. Avoiding fish entirely during pregnancy can actually mean missing out on nutrients that support the baby’s developing nervous system.
Parasites in Raw or Undercooked Salmon
If you cook your salmon, parasites aren’t a concern. Heat kills them. The minimum safe internal temperature is 145°F (63°C), which is the point where the flesh turns opaque and flakes apart easily with a fork.
Raw preparations like sushi, sashimi, and ceviche are a different story. Wild salmon can harbor roundworms (the most common being anisakis) and tapeworms. These parasites live in the fish’s muscle tissue and can cause gastrointestinal symptoms if swallowed alive. Anisakis infection typically causes intense stomach pain, nausea, and vomiting within hours of eating contaminated raw fish.
The FDA’s solution is freezing. Any of these methods will kill parasites effectively:
- Standard freezing: Hold at -4°F (-20°C) or below for 7 days
- Blast freezing: Freeze at -31°F (-35°C) or below until solid, then store at that temperature for 15 hours
- Blast then standard: Freeze at -31°F (-35°C) until solid, then hold at -4°F (-20°C) for 24 hours
Reputable sushi restaurants freeze their wild salmon before serving it raw, following these guidelines. Your home freezer, which typically runs around 0°F (-18°C), doesn’t get cold enough to reliably kill parasites within the FDA’s timeframes. If you want to eat wild salmon raw at home, buy it from a fishmonger who confirms it has been flash-frozen to sushi-grade standards, or look for packaging that specifies it was frozen to the temperatures listed above.
Cooking for Maximum Safety
For most people, the simplest path is cooking. At 145°F internal temperature, all parasites and harmful bacteria are destroyed. You can verify this with an instant-read thermometer inserted into the thickest part of the fillet. If you don’t have a thermometer, the visual cues are reliable: the flesh should be opaque throughout (no translucent spots in the center) and should separate into clean flakes when pressed with a fork.
Some people prefer salmon cooked to a lower internal temperature for texture reasons, around 120°F to 130°F for a more translucent center. This is common in restaurants but does carry slightly more risk with wild-caught fish that hasn’t been previously frozen. If you like your salmon on the rarer side, choosing fillets that have been commercially frozen and thawed gives you the best of both worlds: the parasites are already dead from freezing, so a lower cooking temperature is safer.
Wild vs. Farmed: Which Is Safer?
From a contaminant standpoint, the two are comparable. Wild salmon tends to have slightly higher levels of certain environmental pollutants picked up through the ocean food chain, while farmed salmon historically had higher PCB levels, though modern farming practices have reduced that gap significantly. Both types fall well within safe consumption ranges.
The parasite picture is different. Wild salmon is far more likely to carry parasites than farmed salmon, because farmed fish eat processed feed rather than wild prey. If eating raw salmon is your goal, farmed Atlantic salmon is the lower-risk option. For cooked preparations, the distinction doesn’t matter since heat eliminates the risk either way.
Nutritionally, wild salmon tends to be leaner with slightly less fat overall, while farmed salmon has more total omega-3s alongside more saturated fat. Both are excellent protein sources. The safety profiles are close enough that your choice can come down to taste, texture, price, and environmental preferences rather than health concerns.