Most Atlantic salmon sold in stores comes from farms. Farmed salmon are often exposed to pesticides, antibiotics, and synthetic dyes to enhance their pink color. Tests have shown that farmed salmon contains higher levels of PCBs (polychlorinated biphenyls), which have been linked to cancer.
3. Swordfish
Swordfish are predatory fish, meaning they accumulate mercury from the smaller fish they eat. High levels of mercury can damage the nervous system, especially in children and pregnant women.
4. With
Like swordfish, sharks contain dangerous levels of mercury and other toxins, such as arsenic. Regularly eating shark meat may increase the risk of heavy metal poisoning.
5. King mackerel

King mackerel is on the “do not eat” list of almost all health authorities due to its high mercury content. It is particularly dangerous for children, pregnant women, and nursing mothers.
6. Tilefish (Gulf of Mexico)
Gulf of Mexico tilefish are among the fish most contaminated with mercury. It is often recommended to avoid them altogether, especially for those with mercury sensitivity.
7. Imported catfish
Most catfish sold in grocery stores are imported from countries with lax food safety regulations. These fish are sometimes treated with antibiotics banned in the US and may contain contaminants from polluted waters.
8. Chilean sea bass
Chilean sea bass is known for its buttery texture, but it’s also notorious for mercury buildup. It’s overfished, and most sea bass available on the market is illegally caught or mislabeled.