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Finding Plastic In Seafood | Earth Wise

September 15, 2020 By EarthWise Leave a Comment

Researchers from the University of Exeter in the UK and the University of Queensland in Australia have developed a new method for identifying and measuring the presence of five different types of plastic in seafood.

The researchers purchased oysters, prawns, squid, crabs, and sardines from a market in Australia and analyzed them using the new technique. They found plastic in every single sample.

Their findings showed that the amount of plastics present varies greatly among species and differs between individuals of the same species. The measured plastic levels were 0.04 mg per gram of seafood in squid, 0.07 mg in prawns, 0.1 mg in oysters, 0.3 mg in crabs, and 2.9 mg in sardines.

All the plastics are types commonly used in plastic packaging and synthetic textiles and are increasingly found in marine litter: polystyrene, polyethylene, polyvinyl chloride, polypropylene, and polymethyl methacrylate.

The new method treats the seafood tissues with chemicals that dissolve the plastics present within them. The resulting solution is then analyzed using a highly sensitive technique called Pyrolysis Gas Chromatography Mass Spectrometry which both identifies and quantifies the plastics.

Microplastics are an increasing source of pollution for much of the planet, including the oceans where they are eaten by all types of marine creatures ranging from planktonic organisms to large mammals. Microplastics enter our diet not only from seafood, but also from bottled water, sea salt, beer, and honey, as well as from dust that settles on our food.

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Seafood study finds plastic in all samples

Photo, posted June 23, 2007, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Microplastics with Magnetism

October 7, 2019 By EarthWise 2 Comments

A new method for removing microplastics from the oceans has emerged from, of all things, a science fair project. An Irish 18-year-old named Fionn Ferreira developed his project for the annual Google Science Fair and it won the grand prize of $50,000 in educational funding.

The teenager was walking on the beach in his hometown and ran across a stone with oil and plastic stuck to it and became focused on the problem of microplastics increasingly entering the environment.

His idea was to make use of ferrofluids, which are nontoxic magnetic fluids made of oil and magnetite, which is an iron-based mineral. In the presence of water, the ferrofluids attract microplastics because both have similar properties.

Ferreira added oil and magnetite to water and mixed in a solution of microplastic particles. When the microplastics latched onto the ferrofluids, he dipped a magnet into the solution several times and the magnet removed both substances, leaving clear water. After almost 1000 tests, he demonstrated the method to be 88% effective in removing a variety of microplastics from water; a result even better than his original hypothesis of an 85% removal rate.

Ferreira is planning to further his education at a prestigious chemistry institute in the Netherlands starting in the fall.

According to a recent study, Americans eat, drink and breathe between 74,000 and 121,000 microplastic particles each year and, if they drink bottle water only instead of tap water, an additional 90,000 particles. So, a science fair project that might provide a way to get rid of most these things is definitely prize-worthy.

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