Microplastics have been detected in human lungs and placentas, stool and blood, and the latest finding: heart tissue. In a pilot study published in Environmental Science & Technology, researchers studied 15 patients, ranging in age from 41 to 75, who underwent heart surgery at the Beijing Anzhen Hospital in China. Through the use of laser-direct infrared chemical imaging, researchers discovered nine types of microplastics were found across five types of tissue, with the largest measuring 469 micrometers in diameter. These included polypropylene (used in food packaging), polyethylene terephthalate (used in plastic bottles), polystyrene (used in rigid plastic products like cutlery, CD cases, medical products and automotive parts), polyethylene (used in plastic bags), polyamide (used in textiles), polycarbonate (used in eyewear and medical devices), polyvinyl chloride (used in pipe), polyurethane (used in coatings), and polymethyl methacrylate (used in dental implants and shatter-resistant glass alternatives). Microplastics were also present in pre- and postoperative blood samples.
Given that research has shown the presence of microplastics in organs that have direct exposure to the external environment through various body cavities, the researchers were interested in the potential for organs that are fully enclosed in the human body, like the heart, to be exposed to microplastics. They found that the presence of polymethyl methacrylate, specifically, in certain tissues suggested that the exposure could not be attributed to the surgery itself, but rather some other source. However, the study did also acknowledge that invasive medical procedures are also a route of microplastics exposure, a point that warrants further research.
A press release from the American Chemical Society commented: “Everywhere scientists look for microplastics, they’ve found them…” Where will they look next?