LAS PALMAS, Spain – Scientists and ecologists have warned for years about the risk of untold millions of tons of plastic residue ending-up in our oceans, and according to a Spanish scientific report published on Monday, the result is that our kitchen sea salt is now laced with plastic microparticles.
Plastic is a fairly recent 20th-century phenomenon, but it is estimated that between 4.8 and 12.7 million tons of plastic garbage are dumped every year into our oceans, according to the journal Science in 2015.
Whales and sea turtles ingest the plastic after confusing it with jelly fish, it obstructs their digestive systems and kills them; birds get their wings tangled in plastic material and fish end up with micro fragments embedded in their stomachs. These are some of the consequences of the “seas of plastic” that have become commonplace in our oceans.
Three researchers from the department of chemical engineering at the University of Alicante published their most recent findings in the journal “Scientific Reports,” where they stated that microplastics have already found their way into the sea salt we commonly use to season our food.
Between September 2016 and June 2017, the authors of this study researched salt evaporation ponds, or salterns, located across the Spanish coastlines.
Their conclusion was that the salt harvested in all of these locations contained varying concentrations of plastic microparticles, ranging from 60 to 280 micro-particles per kilo of salt.
Such plastics included Polyethylene terephthalate (PET), which made up 83.3 percent of all plastic discover; polypropylene (PP), which made up 6.7 percent; and polyethylene (PE), which accounted for 3.3 percent of the total.
Their findings seemed to confirm two previous studies published in 2015 by the University of Shanghai that examined Chinese sea salt and found even higher levels of plastic microparticles levels.
The Spanish team also examined another recent study published last spring in “Scientific Reports” by a Malaysian university that apparently reached the opposite conclusion stating they only found traces of plastic.
The problem with this study is that the Malaysian team resorted to 150-micron filters which did not allow them to account for much smaller particles; in the case of the Spanish study, they accounted for plastic particles measuring 30 microns.
The Spanish research team from Alicante led by Maria Iñiguez, Juan Conesa, and Andres Fullana stated that microparticles trapped in salt crystals imply a “background pollution” now present in every ocean.
How much plastic can somebody ingest this way? If we accept the World Health Organization’s recommended daily intake of salt (5 grams maximum), a Spanish consumer would theoretically ingest some 510 micro-particles per year.
This is not a very high concentration if you consider other seafood such as mussels, where a single mussel can contain up to 178 micro fibers.
The long-term problem is that once the biodegradable process has broken the plastic to micro-particle level it can take centuries or even millennia to degrade completely back into nature.