Palos Verdes Shelf Superfund Site – Seafood Consumption Study Summary
The following is a summary of the U.S. Environmental Protection Agency’s (EPA) 2014 report entitled, “Seafood Consumption Study” (Seafood Study or Study) that was completed for the Palos Verdes Shelf Superfund Site (PV Shelf Site).
The PV Shelf Site is a large (approximately 34 square miles) area of contaminated sediment located approximately 2 miles off the coast of the Palos Verdes Peninsula in Los Angeles County, California. Since the 1970s, studies have shown that fish caught between Santa Monica Pier and Seal Beach Pier have elevated levels of Dichloro-Diphenyl-Trichloroethane (DDT) and Polychlorinated Biphenyls (PCBs). Sediment at PV Shelf is a source of DDT- and PCB-contamination in the area.
The presence of contaminated fish has generated public concern regarding the safety of consuming seafood from the area. In order to accurately assess the potential health risks from eating contaminated seafood, information on anglers’ demographics, seafood consumption rates, seafood preparation and cooking methods, species of seafood caught, fishing preferences, contamination awareness, and more was collected, evaluated, and recommendations were made. The Seafood Study is a follow-up to a similar 1994 study that was conducted by the Santa Monica Restoration Project (now called the Santa Monica Bay Restoration Commission) and entitled “Santa Monica Bay Seafood Consumption Study.” In the current Study, anglers were interviewed between February 2012 and January 2013 at piers, jetties, private boats, charter boats, beaches, and intertidal zones from Santa Monica to Seal Beach piers (the Study Area). Key findings from the Seafood Study are summarized below; tables and figures are included at the end of this summary.
STUDY DATA AND FINDINGS
The demographic and ethnic subgroups of anglers identified included Hispanic (37%); Caucasian (24%); Asian including Filipino, Japanese, Korean, Chinese, and Vietnamese (24%); African American (6%); and mixed/other ethnic background (9%). The majority of anglers were men (94%) and the age ranged from 14 to 87 years old. The mean angler age is 44 years old. Hispanics are the most abundant ethnic group on piers and jetties, whereas Caucasians are mostly found on charter and private boats. Table 1 presents the population level angler characteristics for the 693 anglers surveyed.
At least 35 species of fish are caught from the study area and consumed by recreational anglers. The most abundant species caught and consumed include Pacific mackerel (27% of anglers), Pacific sardine (21% of anglers), perch (19% of anglers), topsmelt (19% of anglers), California scorpionfish (14% of anglers), and bass species (12% of anglers). Thirty-nine percent of anglers interviewed (270 anglers out of the 693 total anglers interviewed) reported consuming fish from the Study Area within four weeks prior to the survey (Figure 1). Based on the anglers reported seafood consumption rates (fish or fillet size and frequency), the mean fish consumption rate for anglers of all ethnic backgrounds was calculated to be 18.55 grams per individual per day (g/ind/day). For ethnic angler groups, the average values ranged from a low of 20.7 g/ind/day (Hispanics) to a high of 34.4 g/ind/day (African Americans). African American anglers also had high rates of consuming the five Do-Not-Consume (DNC) fish species that are of particular concern. Figure 2 presents the overall percentage of angler awareness of the contamination from outreach messaging. Figure 3 presents the effectiveness of outreach messaging types, indicating that signs are the most effective mode of communicating the health advisory. Figure 4 presents the change in behavior as a result of the health advisories.
The Seafood Study suggests that there has been a shift in the seafood species caught for consumption. In 1994, the most commonly consumed fish were the Pacific bonito (77.5% of anglers), barracuda (74.2% of anglers), and halibut (69.6% of anglers). In the Seafood Study, the most commonly consumed species were mackerel (27%), Pacific sardine (21%), perch (19%) and topsmelt (19%). The preparation methods remained consistent from 1994 to present; the majority of consumers (63% in the current study and 65% in 1994) reported eating the fish as a steak or fillet without the skin. Since the 1994 study, the percent of anglers who are Caucasian has declined from 43% to 24% while the percentage of Hispanic and Asian have increased from 25% to 37% and 18% to 24%, respectively. Despite the population level changes, trends across fishing modes have remained consistent since 1994. Figures 5 and 6 present the change in ethnicity and consumption behavior of anglers from 1994 to 2014.
As determined from the Seafood Study, the ‘average’ (median) daily seafood consumption rate has decreased from approximately 21 grams per individual per day (g/ind/day) in 1994 to approximately 11 g/ind/day) which suggests that EPA’s Program (that includes extensive public educational outreach, enforcement, and monitoring efforts) have been successful in changing angler consumer behaviors and reducing human health exposure to contaminated fish. Also with regard to the most vulnerable or high-end fish consumers, the Study’s calculated Reasonable Maximum Exposure (RME) rate suggest a decreased consumption rate, this value has not changed or declined sufficiently to warrant a revision of the RME value in a human health risk assessment. Of the anglers surveyed, 61% (425 of 693) reported awareness of the advisory warnings disseminated in the past decade, and of those who reported awareness, 42% (175 of 693) reported adopting a more healthy behavior.
STUDY CONCLUSIONS AND RECOMMENDATIONS
While the Institutional Control efforts have been effective in reducing human health risks by minimizing exposures to contaminated fish from PV Shelf, fish continue to exceed protective levels for human consumption as established in EPA’s Interim Record of Decision. Therefore, the Institutional Controls Program and its Educational Outreach component will continue to serve as a major component of EPA’s interim remedy for the study area. The Seafood Consumption Study provided recommendations to improve future public outreach and education efforts for the PV Shelf Site.
To overcome significant language barriers, Fish Contamination Education Collaborative angler and community outreach workers will continue to be recruited that match the diverse ethnic backgrounds of the Southern California angler population. Increased angler and community outreach efforts to the African American community is being implemented as is outreach efforts to the Hispanic community. Out of the five DNC fish species, anglers expressed the highest rate of intended consumption for Barred Sand Bass. Therefore, additional outreach focused on this species may be needed and will be evaluated upon completion of the EPA 2014-2015 PV Shelf fish sampling activity.
While public educational outreach have made a difference in reducing the public health risk of consuming contaminated fish from the PV Shelf Site, there is more to be done. With a greater understanding of angler fishing practices that is detailed in the Seafood Study, EPA and its FCEC partners will more effectively continue to monitor vulnerable populations and implement activities to reach, educate, and ultimately foster healthy fish consumption behaviors in all who consume fish caught from the PV Shelf Site and Study Area.
The complete Seafood Consumption Study can be found at: http://www.pvsfish.org/images/files/EPA%20Seafood%20Cons%20Study%200415%20FINAL%20COMPILED.PDF