July 16, 2013 — The benefits of seafood are well known. Omega 3s from fish are good for metabolism, while fish oil is thought to help with inflammation in the body. But consumption of certain species of fish can pose health risks, particularly for pregnant women and children.
In a marine biology lab at Roger Williams University, Professor David Taylor placed a small, bite-sized chunk of fish inside a counter-top piece of equipment called a DMA-8 mercury analyzer, which will determine how much mercury this piece of scup contains in its flesh.
"So basically I’m going to put this tissue in a quartz weigh-boat," Taylor said. "It thermally decomposes the sample, basically just burns it, turns it into a vapor."
This DMA-8 has an amalgamator, an atomic absorption spectrometer, and oxygen from a nearby tank is used to carry mercury vapor around the instrument. It is essentially a large, 30,000-thousand-dollar Easy Bake Oven for scientists — one that reaches 600 degrees celsius to turn this piece of scup into ash.
State and local health officials monitor chemical contamination levels through tests like this one, to determine what breed of fish should be eaten, and which ones should be avoided. With the information, government agencies put out advisories. For example, in Massachusetts, consumers and anglers are warned not to eat the bluefish caught off the coast. Don't eat flounder or lobsters from Boston Harbor, or any fish at all caught in New Bedford Harbor.
As for the scup, Taylor finds that the fish is safe.
"The wet weight concentration is roughly .06 parts per million wet weight," Taylor said, which is well below the EPA threshold."
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