MONTROSE CHEMICAL CORP.
Health & Environment
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What Are the Risks at the Site?
Risks and pathways addressed by the cleanup include health risks from people ingesting or touching contaminants in soil, sediments, groundwater, and fish.
To lear more about fish contamination, fish consumption guidlines, and ways to minimize the ingestion of DDTs and PCBs from fish caught in the PV Shelf area, please go to: www.pvsfish.org.
Dichloro-Diphenyl-Trichloroethane (DDT): DDT was developed as the first of the modern synthetic insecticides in the 1940s. It was initially used with great effect to combat malaria, typhus, and the other insect-borne human diseases among both military and civilian populations. It also was effective for insect control in crop and livestock production, institutions, homes, and gardens. DDT's quick success as a pesticide and broad use in the United States and other countries led to the development of resistance by many insect pest species.
In 1972, EPA issued a cancellation order for DDT based on its adverse environmental effects, such as those to wildlife, as well as its potential human health risks. Since then, studies have continued, and a relationship between DDT exposure and reproductive effects in humans is suspected, based on studies in animals. In addition, some animals exposed to DDT in studies developed liver tumors.
DDT is classified as a probable human carcinogen by US. and international authorities and are known to be very persistent in the environment, will accumulate in fatty tissues, and can travel long distances in the upper atmosphere. For more information, please visit: https://www.epa.gov/ingredients-used-pesticide-products/ddt-brief-history-and-status
Polychlorinated Biphenyls (PCBs): PCBs are a group of man-made organic chemicals consisting of carbon, hydrogen and chlorine atoms. The number of chlorine atoms and their location in a PCB molecule determine many of its physical and chemical properties. PCBs have no known taste or smell, and range in consistency from an oil to a waxy solid. Due to their non-flammability, chemical stability, high boiling point and electrical insulating properties, PCBs were used in hundreds of industrial and commercial applications including: electrical, heat transfer and hydraulic equipment,plasticizers in paints, plastics and rubber products, pigments, dyes, and carbonless copy paper.
PCBs have been demonstrated to cause a variety of adverse health effects. They have been shown to cause cancer in animals as well as a number of serious non-cancer health effects in animals, including: effects on the immune system, reproductive system, nervous system, endocrine system and other health effects. Studies in humans support evidence for potential carcinogenic and non-carcinogenic effects of PCBs. The different health effects of PCBs may be interrelated. Alterations in one system may have significant implications for the other systems of the body. For more information, please visit: https://www.epa.gov/pcbs/learn-about-polychlorinated-biphenyls-pcbs
The area of highest DDT and PCB contamination in sediment is located roughly 2 km offshore and extends westward from the outfalls approximately 5 km along the shelf. Because the most significant discharges of DDT and PCBs to the Palos Verdes Shelf ceased in the early 1970s, the most contaminated sediments have gradually been covered over, primarily by solids discharged through the outfalls and by solids eroded from the nearby Portuguese Bend landslide area. The depth in the sediment column to the maximum concentration of DDT is greater than 40 cm on parts of the shelf but is commonly less than 10 cm on the slope. The maximum concentration of DDT exceeds 200 ppm near the outfall pipes; concentrations in excess of 50 ppm extend up to 4 km to the west of the outfalls. The distribution of PCBs follows a similar pattern, although concentrations are about an order of magnitude lower than the DDT.
High levels of DDT and PCBs are found in the active biologic zone of the Palos Verdes Shelf sediments, and fish from the Shelf are contaminated with high levels of DDT and PCBs. Generally speaking, contaminant levels are highest in bottom-feeding fish such as the white croaker and are significantly lower in fish that live higher up in the water column. DDT levels in ocean waters over the site range from 0.6 to 15.8 ng/L, while PCBs range from 0.06 to 1.14 ng/L. These levels all exceed the California Ocean Plan standards for DDT and PCBs. DDT levels in samples from a reference station upcurrent from the Palos Verdes Shelf were 0.20 ng/L, while PCBs were not detected. While DDT and PCBs at the PV Shelf site do not pose a risk for swimming and other types of water contact recreation, they are present at unsafe levels in some fish.
EPA uses performance measures to track environmental results at Superfund sites. If you have any questions or concerns about the measures at this site, please contact the site team members listed under Site Contacts.
Read more about Superfund Remedial Performance Measures.
|Status at this
|What does this mean?|
|Human Exposure Under Control||No||Yes means assessments indicate that across the entire site:
No means an unsafe level of contamination has been detected at the site and a reasonable expectation exists that people could be exposed.Insufficient data means that, due to uncertainty regarding exposures, one cannot draw conclusions as to whether human exposures are controlled, typically because:
|Groundwater Migration Under Control||No||
Yes means EPA reviewed all information on known and reasonably expected groundwater contamination. EPA concluded the migration of contaminated groundwater is stabilized and there is no unacceptable discharge to surface water. EPA will conduct monitoring to confirm that affected groundwater remains in the original area of contamination.
No means EPA has reviewed all information on known and reasonably expected groundwater contamination, and the migration of contaminated groundwater is not stabilized.
Insufficient data means that due to uncertainty regarding contaminated groundwater migration, EPA cannot draw conclusions as to whether the migration of contaminated groundwater is stabilized.
Yes means the physical construction of the cleanup is complete for the entire site.
No means either physical construction is not complete or actions are still needed to address contamination.
|Sitewide Ready for Anticipated Use||No||Yes means:
No means that one or more of these three criteria have not been met. However, a site listed as no may still have redevelopment occurring on portions of the site and may be eligible for additional redevelopment.