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?
What are the health effects of eating fish contaminated with DDTs and PCBs?
Why have I not heard of this problem before?
Are fish caught in areas outside of Los Angeles and Orange Counties safer to eat?
What about other seafood? Is it ok to eat crabs, shrimp caught off the coast of Los Angeles and Orange Counties?
What effect does the runoff after it rains have on the fish?
If I shouldn’t eat certain fish from the red zone, is it okay to swim there?
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?
How can you tell that the fish that is caught in the yellow zone didn’t come from the red zone?
1. What is DDT?
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. 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.
6. Why have I not heard of this problem before?
Since 1985, fish consumption advisories
or warnings have been issued and posted for areas between Pt. Dume and Newport Beach because of elevated levels of DDTs and PCBs. Articles have been published in local newspapers, and some stories have appeared on the television news, but those efforts may not have reached the most affected populations.
From 1999 to 2001, EPA funded the California Department of Health Services to work on a pilot outreach program regarding the health risks associated with consumption of contaminated fish from the Palos Verdes Shelf area. Working in cooperation with several community-based organizations and other agencies, a variety of informational and training materials were developed and distributed.
In 2001, the USEPA and trustees won a lawsuit against the Montrose Chemical Corporation. With additional resources now available, the Fish Contamination Education Collaborative (FCEC) was funded by the USEPA to conduct outreach and education to affected populations on piers, in markets, in classes and through the media. Local community organizations and agencies are spreading the message in 14 languages. The FCEC is a consortium of federal, state and local agencies, community based organizations and local health departments.
7. Are fish caught in areas outside of Los Angeles and Orange Counties safer to eat?
It is likely that fish caught further from the Palos Verdes Shelf will have lower levels of PCBs and DDTs. To be sure, federal governmental agencies periodically analyze fish caught along the coast from Ventura to Dana Point for PCBs, DDTs, dieldrin, chlordane and mercury. The most recent study was published available in 2007 and is being used by the State of California to update current advisories.
You should check for fish consumption advisories in other areas at OEHHA. Also follow the general advice to eat different types of fish from a variety of places, eat smaller legal-size fish, trim away fat, eat only the fillet (not the guts), and cook fish so that the fat drips away. Also see Question 22 for more information on cleaning and cooking fish safely.
The purpose of fish consumption advisories, also called health advisories, is to recommend that people limit or avoid eating certain types of fish caught from specific coastal waters, lakes, or rivers in order to reduce their exposure to harmful chemicals. Because some chemicals may be more harmful for certain groups of people like pregnant women and children, the advisories may include specific recommendations for these groups. Women of childbearing age and young children, who are more sensitive to mercury contamination, should follow the recommendations in the Mercury in Fish brochure.
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. What effect does the runoff after it rains have on the fish?
Runoff after it rains can carry many pollutants like motor oil, household and garden pesticides, litter, bacteria and viruses, and other waste materials from our everyday activities into the storm drains, and eventually the ocean. This pollution can certainly have a negative impact on the environment, fish and other sea life. We can all adopt ways to practice conservation and pollution prevention measures that will serve to actively protect our oceans and rivers.
10. 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.
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?
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. How can you tell that the fish that is caught in the yellow zone didn’t come from the red zone?
There really isn’t a good way to tell if the fish caught in the yellow zone didn’t come from the red zone. Some fish like white croaker
are bottom feeders and tend to stay in one area. Reef fish like rockfish, scorpion fish or kelp bass mainly stay in one place but do not feed in sediments. Barracuda, mackerel and bonito swim over large areas of water and do not feed in sediments, so they are less likely to have DDTs and PCBs contamination.