Micro and nanoplastics could be making their way into our bodies and sticking around our organs, say scientists at Arizona State University, US.
Previous studies on the rate of plastic consumption in humans show that particles can pass through the gastrointestinal tract. In fact, it’s possible that humans may be consuming anywhere from 39,000 to 52,000 microplastic particles a year, according to National Geographic. Evidence of particles can be found in beer, salt, seafood, sugar, alcohol, and honey, as well as some species of fish like shellfish.
But until now, no research has been done on whether they accumulate in our organs. Graduate students Charles Rolsky and Varun Kelkar decided to investigate using samples of brain and body tissue. They started by exposing lung, liver, fat, spleen and kidney tissue to tiny particles of plastic, to work out how to detect if microplastics were present.
Next, 47 samples were taken from human liver and fat and analysed using mass spectrometry. They were looking for numerous types of plastic components within the tissue, including polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene (PE).
Evidence of plastic contamination was detected in every single sample. In particular, the researchers found Bisphenol A (BPA), which is a substance still used in many food containers despite health concerns surrounding it.
“The tissue donors provided detailed information on their lifestyle, diet and occupational exposures," says Rolf Halden, Ph.D, whose lab tested the samples. "Because these donors have such well-defined histories, our study provides the first clues on potential micro- and nanoplastic exposure sources and routes."
When it comes to the effect on human health, not much is known yet about the risks posed. So far, research in wildlife and animals has linked micro and nanoplastic exposure to infertility, inflammation and cancer, but health outcomes in people are unknown.
“We never want to be alarmist, but it is concerning that these non-biodegradable materials that are present everywhere can enter and accumulate in human tissues, and we don't know the possible health effects," says Kelkar.
Scientists define microplastics as plastic fragments less than 5 mm, or about 0.2 inches, in diameter. Nanoplastics are even smaller, with diameters less than 0.001 mm. "You can find plastics contaminating the environment at virtually every location on the globe, and in a few short decades, we've gone from seeing plastic as a wonderful benefit to considering it a threat," adds Rolsky.
The researchers plan to conduct epidemiological studies to assess the dangers of microplastics on human health. Meanwhile, they will be sharing their online tool to help collect results from similar tests going on around the world.
"This shared resource will help build a plastic exposure database so that we can compare exposures in organs and groups of people over time and geographic space," Halden concludes.