Following the Deepwater Horizon Oil Spill in 2010, many people were concerned that seafood was contaminated by either the oil or dispersants used to keep the oil from washing ashore. However, new research suggests that may not be the case.

Researchers at the University of Florida sampled more than 1,000 Gulf of Mexico fish, shrimp, oysters and blue crabs taken from Cedar Key, Fla., to Mobile Bay, Ala., between 2011 to 2013, they found no elevated contaminant levels. In fact, some 74 percent of the seafood tested showed no quantifiable levels of oil contaminants at all.

"Seafood appears as safe to eat now as it was before the spill," Dr. Andrew Kane, associate professor of environmental and global health and director of the Aquatic Pathobiology Laboratory at UF's Emerging Pathogens Institute, said in a statement.

Kane and his team, including researchers from UF's Center for Human and Environmental Toxicology, and the Institute of Food and Agricultural Sciences, tested inshore-harvested species of coastal seafood along the Gulf of Mexico -- typically caught within a half a mile of the coastline. They looked at polyaromatic hydrocarbons (PAHs), which are a component of oil that can accumulate in plankton and microorganisms, and can then be ingested by fish and other seafood. PAHs are monitored because some can cause cancer. The Food and Drug Administration long ago established "Levels of Concern" (LOCs) for PAHs in fish and shellfish. These LOCs are based on the toxicity of specific contaminants, if present, the levels of these contaminants present in seafood, how much seafood people eat, consumer body weight, and other factors.

Contaminant data from sampled seafood is being combined with seafood consumption data from coastal residents who participated in the UF study. Study participants represented potentially "high-end consumers" -- people who may eat a lot more seafood harvested along the Gulf coast than the average consumer in the United States. Survey data was collected at fishing tournaments, seafood festivals, fishing piers, etc., and survey responses that indicated that two-thirds of participants live in households with a commercial or recreational fisher.

These residents consumed anywhere from 200 to 980 percent more seafood (based on the consumers' age and seafood type eaten) than the general public. Even taking into account their substantially higher seafood consumption rates compared to national statistics, Kane said that the extremely small levels of contaminants observed likely represent baseline levels and are probably not sufficient to affect these "high-end consumers."

Although there are still basic science questions to be answered regarding the chemical signature of the Deepwater Horizon oil spill in seafood, and the fate of this oil in the environment, the basic outcome remains positive: researchers don't see evidence that the oil spill has created significant seafood-related risks.