Responding to a study that showed mackerel caught in the Andaman Sea were heavily contaminated with microplastics, Prime Minister Prayut Chan-o-cha on Friday warned the public against carelessly polluting the environment with plastic waste.
"Don't forget that a single plastic bag takes up to 450 years to decompose. So where does the plastic waste left in the environment go? It ends up in our stomachs, just as it did for the mackerel," Gen Prayut told the media yesterday.
He was commenting after an ocean study by Trang's Marine National Park Operation Centre made headlines early this week.
Marine scientists at the centre found that stomachs of mackerel caught off the shore of Hat Chao Mai National Park in Trang province contained on average 78 plastic fragments of 1-5 millimetres in diameter.
"Plastic has its own benefits and negatives, so we need to find a way to use it appropriately," said Gen Prayut, who last year approved a policy to ban the use of single-use plastic bags and items such as straws and Styrofoam, by 2021.
The premier proposed that schools also ban plastic bags from their premises.
Krisda Sirampuj, director of the International Anti-Ageing Medicine Institute, told media that microplastic contamination is now ubiquitous.
Recent research shows that contamination by microplastics -- whose everyday sources include cigarette butts, artificial textiles, car tyres and the plastic pellet-making industry -- is widespread in the soil, rivers, on high mountains and even in Arctic ice.
"Its atomic size enables it to enter our bodies as we breathe in the [polluted] air, eat food and drink water contaminated with microplastics," he said.
Microplastic particles come in various sizes, some invisible to the naked eye and smaller than the now-infamous air pollution particles known as PM2.5, with a diameter measuring 1/20 of a human hair.
Researchers from the National University of Singapore (NUS) early this year discovered more than 400 types of bacteria on 275 pieces of microplastic collected from beaches, Dr Krisda said.
"These bacteria cause several illnesses in human, including gastroenteritis and septicemia, as well as bleaching coral," he said.
"Despite claims that humans are capable of excreting microplastic consumed, we shouldn't forget that certain types of microplastic are so small they are measured in nano-metres and can penetrate into human cells," said Dr Krisda.