What is DDT?
What are PCBs?
How did DDTs and PCBs get into the Los Angeles and Orange Counties Coastal environment?
How widespread or severe is the chemical (DDTs and PCBs) contamination off the coasts of Los Angeles and Orange Counties?
How can you tell if a fish has DDTs or PCBs contamination?
What are the health effects of eating fish contaminated with DDTs and PCBs?
I have been eating fish caught off the coast for years, how is this affecting my health now?
What about other seafood? Is it ok to eat crabs, shrimp caught off the coast of Los Angeles and Orange Counties?
If I shouldn’t eat certain fish from the red zone, is it okay to swim there?
How can you identify white croaker?
Why does white croaker have higher levels of DDTs and PCBs?
How do I know that the fish I buy in the market doesn’t come from the contaminated areas of LA and Orange Counties?
What effect does giving the skin and fatty parts to pets have?
DDT is a pesticide that was widely used in the United States until the 1970’s to control insects that destroy crops and carry diseases like malaria. In the environment, DDT breaks down into DDE and DDD; thus we use the term “DDTs” to refer to all DDT compounds that may be present. When DDTs were found to be harmful to both human health and wildlife, the use of DDT was banned in the United States. However, because of their stable chemical structures, DDTs will stay in the environment for a very long period of time. DDT is still being used in some countries such as India and Mexico
2. What are PCBs?
PCBs, or polychlorinated biphenyls, are a group of man-made chemicals that were widely used in industrial processes, such as in the production of electrical equipment, because of their insulating properties. Their use was also banned in the 1970s because they were found to harm both human health and wildlife. However, because of their stable chemical structures, PCBs don’t break down easily in the environment.
3. How did DDTs and PCBs get into the Los Angeles and Orange Counties Coastal environment?
Montrose Chemical Corporation manufactured the pesticide DDT at its former chemical plant near Torrance, California from the 1940s until the 1980s. Industrial wastewater containing DDT was released into the sewer system up until the early 1970’s. Other industries released polychlorinated biphenyls, or PCBs. The DDT and PCBs got into the sewer system and ultimately flowed out of the outfall pipes located off White Point on the Palos Verdes Shelf.
4. How widespread or severe is the chemical (DDTs and PCBs) contamination off the coasts of Los Angeles and Orange Counties?
More than a 100 tons of DDTs and about 11 tons of PCBs were deposited in the sediments on the ocean bottom and cover over a 17 square mile area, from Point Fermin to the southern edge of Redondo Canyon, northwest of the Palos Verdes Peninsula. The highest levels of DDTs and PCBs in ocean sediment were found about one to three miles off shore of the Palos Verdes Peninsula. Enough contamination is present between Point Dume and Newport Pier, that fishing advisories
have been issued for multiple fishing areas
between these points.
5. How can you tell if a fish has DDTs or PCBs contamination?
with DDTs and PCBs do not look, taste or smell any different than fish that are not contaminated. That is why it is important to follow the fish consumption advisories
and recommendations for Los Angeles and Orange Counties.
6. What are the health effects of eating fish contaminated with DDTs and PCBs?
The more contaminated fish
you eat over your lifetime, the greater your risk of developing health problems
related to DDTs or PCBs. Eating fish with DDTs and PCBs does not make people sick right away. However, these chemicals can build up and stay in your body for a long time. This might cause health problems
Health effects associated with DDTs and PCBs include: cancer, liver damage, and effects on the immune, endocrine, neurological, and reproductive systems. Many effects have only been shown in animal tests, but could occur in humans. Health risks resulting from exposure to these chemicals may also be higher for infants and young children. During pregnancy and lactation, mothers can pass DDTs and PCBs on to their infants. These chemicals can then affect overall growth and development, and brain development and function.
Some children born to mothers with high amounts of PCBs in their bodies, as a result of eating fish with high levels of PCBs, showed delayed growth and development. However, the levels of PCBs in the fish eaten by these mothers were 5 to 10 times higher than levels of PCBs found in fish from the coasts of Los Angeles and Orange Counties.
back to top
7. I have been eating fish caught off the coast for years, how is this affecting my health now?
It is difficult to say if and how your health
is being affected now. This is because whether or not your experience health effects
from eating locally caught fish depends on how much fish you eat, the type of fish you eat, which parts of the fish you eat, and how often these fish are eaten. Generally if you eat fish within the recommended amounts, you minimize your chances of developing health problems
related to chemicals that might be in the fish.
Other factors such as genetics, your total diet, and overall lifestyle also influence your health. If you eat white croaker from the LA coast on a weekly basis, for example, you may have high levels of PCBs and DDTs in your body, but that does not mean that you would experience health effects.
8. What about other seafood? Is it ok to eat crabs, shrimp caught off the coast of Los Angeles and Orange Counties?
Not much is known about DDT and PCB contamination in shellfish. However, it would be best to not eat much shellfish caught from the red zones, because DDTs and PCBs can build up in the fatty parts. You should especially avoid eating the hepatopancreas portion of lobster, more commonly known as the butter or tomalley, caught in the red zone because its high fat content can store unsafe levels of DDTs and PCBs. Shellfish may also be unsafe to eat because of paralytic shellfish poisoning and domoic acid, which are chemicals that cannot be removed by cooking. Also uncooked shellfish may be unsafe to eat because they may contain bacteria like vibrio parahaemolyticus and parasites like nematodes or roundworms and tapeworms. Check with your local health department regarding the most current recommendations. You can also call the Paralytic Shellfish Poisoning (PSP) Hotline: (800) 553-4133.
9. If I shouldn’t eat certain fish from the red zone, is it okay to swim there?
There is no known DDTs or PCBs related health risk
associated with swimming in the coastal areas around Palos Verdes where these contaminants are present in the offshore sediments. These chemicals stay more in the sediment than in the water. However, there are health risks
posed by swimming in waters that have high levels of bacteriological and viral contaminants. To find out information on the water quality for swimming in Los Angeles and Orange Counties go to the Heal the Bay website
and check out their weekly updated Beach Report Card or contact the local health department.
10. How can you identify white croaker?
is called different names, including tomcod or kingfish. A few identifying features of white croaker
include: 12 – 15 spines on dorsal fin, black spot just above the pectoral fin which is the fin adjacent to the gill, horizontal mouth, slightly protruding snout. White croaker may resemble queenfish.
11. Why does white croaker have higher levels of DDTs and PCBs?
feed directly off the bottom of the ocean floor where the chemicals like DDTs and PCBs are located. White croaker is also a fatty fish and DDTs and PCBs tend to build up in the fatty tissue. White croaker caught from yellow zone areas generally have lower levels of DDTs and PCBs than those caught from the red zone areas.
12. How do I know that the fish I buy in the market doesn’t come from the contaminated areas of LA and Orange Counties?
Commercial fishing for white croaker
is banned in the area of the Palos Verdes Shelf that has the highest known DDTs and PCBs contamination in the ocean sediment. In general, the fish sold in local stores should not come from the affected areas. More fish sampling is occurring to better define if the area where commercial fishing for white croaker
is banned should be expanded. Some white croaker
with high levels of DDTs and PCBs were found in a few markets. Some people who may be supplying fish to markets may not be aware of these contaminated areas. Efforts to provide education and outreach to market owners to promote buying fish from approved sources are underway. The USEPA samples and test fish from markets in Los Angeles and Orange Counties to determine whether highly contaminated white croakers are still reaching the local retail markets.
13. Will cooking the fish remove the chemical contaminants?
Unlike bacterial and viral contaminants, simply cooking fish contaminated with DDTs and PCBs will not completely remove the chemicals. Cooking and some preparation methods will reduce the levels of DDTs and PCBs in fish. These methods include removing the fatty parts of the fish, including the skin, guts, fat, fatty dark meat along the entire length of the fillet and all the belly fat. Eat only the cooked fillet. Bake, broil, steam or grill fish and let the cooking juices drip away. Use only the fillet when making soups, caldos, stews, or chowders.
See all FAQ