Sea salt around the world is contaminated by plastic pollution, adding to experts’ fears that microplastics are becoming ubiquitous in the environment and finding their way into the food chain via the salt in our diets.
New studies have shown that tiny particles have been found in sea salt in the UK, France and Spain, as well as China and now the US.
Researchers believe the majority of the contamination comes from microfibres and single-use plastics such as water bottles, items that comprise the majority of plastic waste. Up to 12.7m tonnes of plastic enters the world’s oceans every year, equivalent to dumping one garbage truck of plastic per minute into the world’s oceans, according to the United Nations.
“Not only are plastics pervasive in our society in terms of daily use, but they are pervasive in the environment,” said Sherri Mason, a professor at the State University of New York at Fredonia, who led the latest research into plastic contamination in salt. Plastics are “ubiquitous, in the air, water, the seafood we eat, the beer we drink, the salt we use – plastics are just everywhere”.
Mason collaborated with researchers at the University of Minnesota to examine microplastics in salt, beer and drinking water. Her research looked at 12 different kinds of salt (including 10 sea salts) bought from grocery stores around the world.
Mason found Americans could be ingesting upwards of 660 particles of plastic each year, if they follow health officials’ advice to eat 2.3 grammes of salt per day.
The health impact of ingesting plastic is not known. Scientists have struggled to research the impact of plastic on the human body, because they cannot find a control group of humans who have not been exposed.
“Everybody is being exposed to some degree at any given time, from gestation through death,” researchers from Johns Hopkins Bloomberg School of Public Health and Arizona State University wrote in 2013. “Detectable levels of [the plastic] bisphenol A have been found in the urine of 95% of the adult population of the United States.”
Sea salt around the world is contaminated by plastic Photograph MirageC/Getty Images
. . . The research also comes after a Guardian analysis found 1m plastic bottles are purchased per minute, and that recycling efforts are failing to keep pace with production, which is expected to quadruple by 2050. Some environmentalists have said the threat of plastic pollution now “rivals climate change”.
Mason’s work adds to research on plastics in salt from other countries around the world, including in Spain and China.
In August, Spanish researchers concluded “sea products are irredeemably contaminated by microplastics” and there is “a background presence of microplastics in the environment”, in a study published in Scientific Reports in Nature. There, scientists tested 21 types of table salt and found plastic in all of them. The most common type of plastic they found was polyethylene terephthalate [PET], the material used to make plastic bottles.
This spring, a group of scientists from France, the UK and Malaysia tested 17 types of salt from eight different countries and examined what they believed were plastic particles. They found plastic in all but one sample and found the most of the plastic was from polyethylene and polypropylene.
Scientists first found plastics in salt in China in 2015. Microscopic plastic particles from face scrubs, cosmetics, and shards of plastic bottles were found in samples of 15 salt products found in Chinese grocery stores.
Some researchers, such as Mason, now believe sea salt could be more vulnerable to plastic contamination because of how it is made, through a process of dehydration of sea water.
“It is not that sea salt in China is worse than sea salt in America, it’s that all sea salt – because it’s all coming from the same origins – is going to have a consistent problem,” said Mason. “I think that is what we’re seeing.”
… Mason’s study also looked at how drinking water and beer are contaminated with plastic. …’ We have to focus on the flow of plastic and the pervasiveness of plastics in our society and find other materials to be using instead.”
By Jessica Glenza in New York, The Guardian,
September 8, 2017