At Arizona State University (ASU), scientists conducted a study that found nano- and micro-plastics could enter our bodies and stick around our organs, potentially causing harm.
Previous research on humans’ plastic consumption rate has shown that these particles can pass through the gastrointestinal tract. According to National Geographic, humans may be consuming 39k to 52k microplastic particles per year. How are humans consuming so much plastic? Plastic particles can be found in many products we consume, such as salt, sugar, beer, alcohol, honey, and seafood.
Graduate students Varun Kelkar and Charles Rolsky decided to discover whether these plastic particles accumulate in our organs. They conducted experiments using samples of body and brain tissue. First, they exposed the liver, lung, spleen, fat, and kidney tissue to plastic particles to figure out how to distinguish if microplastics were present.
Then, forty-seven samples were obtained and analyzed from human liver and fat via mass spectrometry. They found evidence of plastic contamination in every single sample. The researchers looked for numerous types of plastic matter within the tissue, such as polyethylene, polyethylene terephthalate, and polycarbonate, but most of the plastic found was a substance used in many food containers, known as bisphenol-A.
Rolf Halden, Ph.D., whose laboratory tested the samples, explained, “The tissue donors provided detailed information on their lifestyle, diet, and occupational exposures. Because these donors have such well-defined histories, our study provides the first clues on potential micro-and nano plastic exposure sources and routes.”
Regarding plastic exposure to human health, scientists still don’t know the extent of the risks posed. Researchers are also exploring whether gut microbes could help keep particles from being absorbed: a kimchi-derived bacterium bound nanoplastics and increased their excretion in mice, though it has not yet been tested in humans. However, previous studies in animals and wildlife have linked nano- and micro-plastic exposure to infertility, inflammation and cancer, suffocation, and death.
Kelkar noted, “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.”
Microplastics are plastic bits less than 5 mm (around 0.2 inches) in diameter, while nanoplastics are smaller than that, with diameters under 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,” Rolsky said.
The ASU scientists plan to conduct epidemiological studies to evaluate the dangers of microplastics to human health. Simultaneously, they will collect data from similar tests going on worldwide via their online tool. “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 explained.
