Microplastics (微塑料) are small pieces of plastic that enter and pollute the environment. Microplastics are not a specific kind of plastic, but any type of plastic piece that is less than five millimeters (毫米) in length.
The team, from South Korea's Incheon National University and Greenpeace East Asia, examined 39 brands of salt from 2l countries. Of these, 28 were sea salt, 9 were rock salt, and 2 were lake salt. Microplastics were not found in three of the samples (样品) : refined (精制的) sea salt from Taiwan, China, refined rock salt from Chinese mainland, and unrefined sea salt in France. Salt made in Asia had by far the most microplastics of all the samples, which has to do with where plastic most often enters the ocean. Nine of the top 10 sea salt are sampled with the highest amount of microplastics that come from Asia.
Actually, microplastics are everywhere. Sea salt and lake salt are made by evaporating (蒸发) water and getting the salt that remains. Plastic waste comes into the bodies of water from rivers, so it's no surprise to find microplastics in salt. Scientists have been finding microplastics in salt for years, including in salt from countries in Asia, Europe, and Africa. But the latest study goes a step further, finding that looking at where the salt was produced is a good way to find how much plastic pollution is in that country.
According to their results, the researchers said that an adult ingests (摄入) about 2,000 pieces of microplastics in salt per year. But microplastics in salt amount to about 6%of a person's total microplastics ingestion. Microplastics have also been found in water, fish and both indoor and outdoor air. All together, an adult ingests over 32,000 pieces of microplastics per year. 80% of them come into our bodies with the air.
It's almost impossible for humans to avoid microplastic pollution.
