Mercury Levels in New Jersey Fish Higher than FDA Estimates

Newswise — Mercury concentrations in certain types of fish sold in New Jersey exceeded levels predicted by FDA data, according to a study published today in the March issue of Environmental Health Perspectives. The study, part of an effort to explore overall how information communicated in public health advisories might be enhanced, was the first regional study of mercury levels in commercial fish that examined fish availability, cost, and consumer preference as variables in consumer choice.

Researchers analyzed mercury content in three types of commonly available New Jersey fish—tuna, flounder, and bluefish—purchased between July and October 2003. They compared mercury levels by species and region, store type, and socioeconomic level of the community in which the sample was purchased. The research team purchased six additional types of widely available fish from central New Jersey markets (Chilean sea bass, porgy, red snapper, croaker, cod, and whiting) and two types of shellfish (shrimp and scallops) to compare actual mercury levels against levels predicted based on FDA data.

As expected, the species varied in mercury level, with tuna containing the highest concentration and flounder the lowest. However, sea bass, whiting, shrimp, and tuna contained higher mean mercury levels than those levels estimated by the FDA on its seafood information website (http://www.cfsan.fda.gov/~frf/sea-mehg.html). The mean level found in croaker exceeded the FDA estimate nearly threefold.

"The FDA database appears to be cumulative from work from 1990 to 1992," the study authors write. "The discrepancies suggest that the FDA and state governments should undertake a broad spectrum survey of mercury and other contaminants in fish to update their database. From a state regulatory perspective, data that show discrepancies between local data and FDA data suggests that site-specific data may be required before consumption information or advisories are prepared."

While there was little variability based on store type or the economic vitality of the neighborhood in which the fish was sold, one regional difference emerged: flounder purchased at fish markets along the New Jersey shoreline had higher mercury levels than flounder purchased at markets in other areas.

Despite this finding, the authors suggest that flounder may be the best choice for consumers because of low mercury content, ready availability, and affordable cost. They also point out that fish is still an important source of protein and nutrients.

"This study suggests that the amount of mercury in fish may vary not only by species but also by region. Further regional studies like this one could provide much more complete information to allow the most accurate public health advisories," says Dr. Jim Burkhart, science editor for EHP.

The lead author of the study was Joanna Burger of Rutgers University. Other authors included Alan H. Stern and Michael Gochfeld. The article is available free of charge at http://ehp.niehs.nih.gov/members/2004/7315/7315.html.

Funding sources for the research as reported by the authors included the Office of Science, Research, and Technology at the New Jersey Department of Environmental Protection, the National Institute of Environmental Health Sciences (NIEHS), the Consortium for Risk Evaluation with Stakeholder Participation, and the Environmental and Occupational Health Sciences Institute.

EHP is published by the NIEHS, part of the U.S. Department of Health and Human Services. EHP is an Open Access journal. More information is available online at http://www.ehponline.org/.