Heavy heart: Researchers find microplastics in heart tissue but health effects remain uncertain

10 Aug 2023 --- In a pilot study of people who underwent heart surgery, researchers in American Chemical Society’s (ACS) Environmental Science & Technology have found microplastics in heart tissues. The scientists also report evidence suggesting that microplastics were unexpectedly introduced during surgery procedures. 

Microplastics are plastic fragments less than five millimeters wide. Previous research has shown that they are present in human blood and brain and are ubiquitous in the environment. Yet, many organs and tissues are fully enclosed inside a person’s body, and scientists lack information on their potential exposure to, and effects from, microplastics. 

In an experiment, researchers Kun Hua, Xiubin Yang and colleagues collected heart tissue samples from 15 people during cardiac surgeries and pre- and postoperative blood specimens from half of the participants. 

The study was published in Environmental Science & Technology.

The technique detected thousands of individual microplastic pieces in most heart tissue samples.Evidence for plastic in heart
The team analyzed the samples with laser direct infrared imaging and identified 20 to 500-micrometer-wide particles made from eight types of plastic, including PET, polyvinyl chloride and poly(methyl methacrylate). 

The technique detected 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 few participants, the researchers say they have provided preliminary evidence that various microplastics can accumulate and persist in the heart and its innermost tissues. 

They add that the findings show that invasive medical procedures are an overlooked route of exposure to microplastics, providing direct access to the bloodstream and internal tissues. 

Microplastic danger?
Whether microplastic exposure poses an actual threat to human health remains yet to be investigated. Packaging Insights speaks to Dr. Chris DeArmitt FIMMM, FRSC, CChem, President of Phantom Plastics, who says that dust is a greater proven danger to human health. 

“When it comes to microplastics, they make up 0.001% of dust particles we ingest. They have been tested and found to be safe, as safe as natural particles like clay or cellulose, which is what plants and trees are made of.”

Although there is overall concern about microplastics in the public space, he asserts that “large studies have demonstrated that is only because the media have dramatically distorted reality. A peer-reviewed study compared what scientists say about microplastics where the vast majority of studies found no real danger to what the media reported to the public where over 90% of articles said there was a definite danger.”Microplastics are ubiquitous in the environment but whether they are a threat to human health remains to be determined.

“Danger is relative, so it is worth noting that while microplastics are 0.001% of particles we ingest and found to be safe, the other 99.999% contains proven toxins and cancer-causing substances, sometimes in rather large concentrations.” 

Examples include quartz, wood dust and leather dust, all known to cause cancer in humans as well as toxins like mercury, lead and arsenic. 

“What worries me as a scientist, is that we are ignoring very real and proven dangers because of an irrational ‘plastiphobia,’” says DeArmitt. 

When discovering plastic particles in the human body, DeArmitt says that the finding sounds shocking at first. 

“However, when you look at the science, this has been known for over 20 years. All kinds of dust particles, like soot, titanium dioxide etc., enter the body and can move around. This has been happening for millennia because dust is everywhere, and the body has built up defenses. So while a world free of dust would be good, there is no cause for panic.”

The researchers conclude that more studies are needed to fully understand the effects of microplastics on a person’s cardiovascular system and their prognosis after heart surgery, the researchers conclude.

By Natalie Schwertheim