Researchers at the University of California San Diego’s Scripps Institution of Oceanography (UCSD) have discovered that location is vital to determining the amounts -- and types -- of pollutants found in fish.
The study, published in the Environmental Health Perspectives June 2017 edition, revealed that levels of persistent organic pollutants (POPs) is greater in industrial areas of the northeast Pacific and northeast Atlantic than in the Western Pacific Ocean.
POPs are compounds that are commonly used in agriculture and manufacturing processes, such as pesticides, flame retardants and electrical coolants, according to the Scripps Institute of Oceanography.
Although many compounds have been banned, they still exist in the environment and accumulate in organisms like fish.
Researchers harvested 117 yellowtail tuna caught at 12 locations world-wide and analyzed the dorsal muscles to determine POP levels.
Researchers said 90 percent of the fish caught in the northeast Atlantic and 60 percent caught in the Gulf of Mexico had POP levels that would have made them unadvisable for consumption in people pregnant, nursing or with compromised immune systems, according to the Scripps Institute of Oceanography.
The majority of the fish caught, however, would have been considered safe for consumption, according to the study.
Capture location was not an element typically assessed in POP studies before. Species, whether the fish is farmed or caught in the wild, and the fish’s hierarchical level in the ecosystems are the more common elements taken into consideration.
Past studies showed a correlation in the amount of fatty tissue to the POPs found in fish, however, the recent study revealed a greater correlation of POPs to the location a fish is caught than the amount of fatty tissue.
“An important issue raised by the study is how to guide science and policy on possible hazards associated with these chemicals in our food sources,” said Scripps postdoctoral researcher Sascha Nicklisch, the leader of the study, in a statement.
The study suggests location would be a better method of determining POPs in food sources to help reduce human exposure to pollutants, according to the Scripps Institute of Oceanography.