Microplastic Particles Are Found Deep in Human Lungs

Microplastic particles have been discovered in the lungs of live human patients. A team of researchers from Hull York Medical School and the University of Hull in the United Kingdom has published a study in the journal Science of the Total Environment that reveals 39 microplastics found in 11 of 13 samples tested. This was much higher than the researchers had expected to find, based on previous lab tests.

While there has been prior evidence of plastic in lung tissue, none has been as robust as this, and none has found it in the lungs of living humans. Only samples taken from cadavers had revealed particles in the past, which is why this data is described as "an important advance in the field of air pollution, microplastics and human health."

Lead study author Dr. Laura Sadofsky tells Treehugger, "The tissue was from patients undergoing chest surgery as part of their medical care, but we don't know if the particles had any effect on their health. We also don't know if these particles are present in everyone."

Out of the 39 pieces found in lungs, 12 different types of microplastic were identifiable. Polypropylene was most common (23%), followed by polyethylene terephthalate, or PET (18%), resin (15%), polyethylene (10%), and polytetrafluoroethylene (10%), which includes synthetic polymers like Teflon. Nearly half were in fiber form (49%).

Surprising Results

Some of the microplastics were substantially larger than the minimum size researchers previously thought particles had to be in order to enter the lungs. 

The researchers wrote in the study's discussion, "It could be that there may be a pre-conceived assumption about the particle sizes which are inhalable and able to make it into the lower airway, but in this study, and others, particles bigger than these are being reported, and therefore, it may be time to revisit these numbers and investigate what sizes can be inhaled."

Despite being larger than anticipated, people may be inhaling these particles without noticing. Dr. Laura Sadofsky tells Treehugger, "We and others have previously shown that microplastics are present in the air that we breathe, so it is possible that we are inhaling these particles without noticing."

The researchers were taken back at how far down the microplastics had migrated in the lungs. Eleven pieces were found in the upper part, seven in the middle part, and 21 in the lower part. 

Dr. Sadofsky said in a press release, "We did not expect to find the highest number of particles in the lower regions of the lungs, or particles of the sizes we found. This is surprising as the airways are smaller in the lower parts of the lungs, and we would have expected particles of these sizes to be filtered out or trapped before getting this deep into the lungs." 

Curiously, males had more particles than females. Every male sample contained particles, while two out of five female samples had none. The researchers suggested that this could be because female airways are smaller than males'.

Microplastics Are Prevalent

It is an alarming discovery that adds to the growing evidence of plastic's proliferation throughout our world and our bodies. Microplastic particles have already been detected in stool samples and blood. They are likely entering bodies from a range of sources that include household dust, air, soil, seawater, food and beverage containers, clothing, home furnishings, degrading tires, and more. 

This research is a powerful reminder of the efforts we require to curb plastic usage—or at least start using it more judiciously. Lower demand will lead to lower production, which creates less waste overall for a world ill-equipped to handle it.

In their conclusion, the researchers wrote that now that microplastics' presence has been confirmed in human lungs, future studies can focus on any potential health effects that come from inhalation.