While examinations for microplastics in our innermost organs that aren’t directly exposed to the environment are still limited, researchers doing a pilot study of people after cardiac surgery recently found microplastics in many heart tissues.
They also report evidence suggesting that microplastics were unexpectedly introduced during the procedures.
Microplastics are plastic fragments less than 5mm wide, or about the size of a pencil eraser. They can enter the body through mouths, noses and other body cavities with connections to the outside world, yet many organs and tissues are fully enclosed inside the body, and scientists lack information on their potential exposure to, and effects from, microplastics.
Kun Hua, Xiubin Yang and colleagues from Beijing Anzhen Hospital in China wanted to investigate whether these particles have entered people’s cardiovascular systems through indirect and direct exposures.
In the pilot experiment, they collected heart tissue samples from 15 people during cardiac surgeries, as well as pre- and post-operation blood specimens from half of the participants.
They then analysed the samples with laser direct infrared imaging and identified 20 to 500 micrometre-wide particles made from eight types of plastic, including polyethylene terephthalate, polyvinyl chloride and poly (methyl methacrylate).
This technique detected tens to thousands of individual microplastic pieces in most tissue samples, though the amounts and materials varied between participants. All of the blood samples also contained plastic particles, but after surgery their average size decreased, and the particles came from more diverse types of plastics.
Although the study had a small number of participants, the researchers say they have provided preliminary evidence that various microplastics can accumulate and persist in the heart and its innermost tissues, and that the findings show how invasive medical procedures are an overlooked route of microplastics exposure, providing direct access to the bloodstream and internal tissues.
More studies are needed to fully understand the effects of microplastics on a person's cardiovascular system and their prognosis after heart surgery, they wrote in Environmental Science & Technology.
Study details
Detection of various microplastics in patients undergoing cardiac surgery.
Yunxiao Yang, Enzehua Xie, Zhiyong Du, Zhan Peng, Zhongyi Han, Linyi Li, Rui Zhao, Yanwen Qin, Mianqi Xue, Fengwang Li, Kun Hua, Xiubin Yang.
Published in Environmental Science & Technology on 13 July 2023
Abstract
Microplastics have been detected in human stool, lungs, and placentas, which have direct exposure to the external environment through various body cavities, including the oral/anal cavity and uterine/vaginal cavity. Crucial data on microplastic exposure in completely enclosed human organs are still lacking. Herein, we used a laser direct infrared chemical imaging system and scanning electron microscopy to investigate whether microplastics exist in the human heart and its surrounding tissues. Microplastic specimens were collected from 15 cardiac surgery patients, including 6 pericardia, 6 epicardial adipose tissues, 11 pericardial adipose tissues, 3 myocardia, 5 left atrial appendages, and 7 pairs of pre- and postoperative venous blood samples. Microplastics were not universally present in all tissue samples, but nine types were found across five types of tissue with the largest measuring 469 μm in diameter. Nine types of microplastics were also detected in pre- and postoperative blood samples with a maximum diameter of 184 μm, and the type and diameter distribution of microplastics in the blood showed alterations following the surgical procedure. Moreover, the presence of poly(methyl methacrylate) in the left atrial appendage, epicardial adipose tissue, and pericardial adipose tissue cannot be attributed to accidental exposure during surgery, providing direct evidence of microplastics in patients undergoing cardiac surgery. Further research is needed to examine the impact of surgery on microplastic introduction and the potential effects of microplastics in internal organs on human health.
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