Chemicals in Fish

Certain chemicals can be of potential health concern because of their toxicity and their ability to accumulate in fish tissue. Harmful chemicals enter the environment through natural processes, industrial and agricultural use, mining, spills, and improper disposal. Fish can take in these chemicals from the food they eat or the water in which they live.

The majority of fish consumption advisories in California are issued because of mercury, followed by polychlorinated biphenyls (PCBs) and, in a few cases, legacy pesticides (pesticides that are no longer used but remain in the environment), selenium, or polybrominated diphenyl ethers (PBDEs).

You can reduce your exposure to harmful chemicals by following our advisories and tips for catching, preparing, and cooking fish.

Mercury

• Mercury is a metal found in coal, rocks, and soil, and has been detected in fish all over the world.
• Learn more about mercury.

PCBs

• Polychlorinated biphenyls (PCBs) are industrial chemicals previously used in electrical transformers, plastics, and lubricating oils.
• Learn more about PCBs.

Legacy pesticides: Chlordanes, DDTs, Dieldrin, and Toxaphene

• These pesticides were banned years ago but are still found in some fish in certain California water bodies.
• Learn more about legacy pesticides.

Selenium

• Selenium is a naturally occurring metalloid and an essential micro-nutrient.
• Learn more about selenium.

PBDEs

• Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants historically used in a variety of consumer products including furniture, textiles, automotive parts, and electronics.
• Learn more about PBDEs.

PAHs

• Polycyclic aromatic hydrocarbons (PAHs) may be formed by burning materials and cooking food and are the chemicals of concern in oil.
• Learn more about PAHs.