Microplastics Detected Deep in Living Human Lungs for the First Time
In a finding that is sure to intensify global concern about plastic pollution, researchers at the University of Hull and Hull York Medical School in the United Kingdom have published the first study to detect microplastic particles in the deep lung tissue of living human patients. The research, published this week in the journal Science of the Total Environment, found plastic particles in 11 of the 13 lung tissue samples analyzed.
While previous studies had found microplastics in human blood, placental tissue, and even the brain, the detection in deep lung tissue of living patients represents a significant step in understanding how these particles accumulate in the respiratory system.
What the Researchers Found
The study analyzed tissue samples obtained during routine surgical procedures from 13 patients at Castle Hill Hospital in East Yorkshire. Using Raman microspectroscopy, the researchers identified a total of 39 microplastic particles across the samples, with an average of three particles per sample.
The most commonly identified plastic types were:
- Polypropylene (PP): Found in 9 of 13 samples, commonly used in food packaging and textiles
- Polyethylene terephthalate (PET): Found in 7 of 13 samples, the primary material in plastic bottles
- Polystyrene: Found in 4 of 13 samples, used in disposable food containers
- Polyethylene: Found in 3 of 13 samples, one of the most widely produced plastics globally
What surprised the researchers most was the location of the particles. Microplastics were found not just in the upper airways, where the body natural filtration mechanisms might be expected to trap them, but in the lower lobes and deep alveolar tissue where gas exchange occurs.
"We did not expect to find the number and types of particles we did in the lower regions of the lungs. It is concerning because those areas of the lung are where the body is most vulnerable to irritation and where particles are hardest to clear," said Dr. Laura Sadofsky, the study lead author.
Health Implications Remain Uncertain
The critical question that this study cannot yet answer is what health effects, if any, these embedded particles are causing. Researchers note that the presence of foreign particles in lung tissue can trigger chronic inflammatory responses, and there is laboratory evidence suggesting that certain plastic polymers can cause oxidative stress in lung cells.
Pulmonologist Dr. Jonathan Grigg of Queen Mary University of London, who was not involved in the study, called the findings "concerning but not yet alarming." He noted that the human lung is exposed to many types of particulate matter throughout life, from air pollution to occupational dust, and that the body has developed mechanisms to cope with foreign particles.
"The key question is dose and duration. Are we reaching levels of microplastic accumulation that begin to impair lung function or increase disease risk? We simply do not know yet, and that uncertainty itself is a compelling reason to fund more research in this area," he said.
A Growing Body of Evidence
This study adds to a rapidly expanding body of research documenting the presence of microplastics throughout the human body. A Dutch study in 2022 first detected microplastics in human blood, while Italian researchers found them in human placental tissue the same year. More recent studies have identified microplastic particles in the human brain, liver, and kidney tissue.
The World Health Organization has acknowledged the need for more research on the health effects of microplastic exposure but has stopped short of declaring them a direct health risk, citing insufficient evidence of harm at current exposure levels.
What Can Be Done
Environmental scientists say that while individual actions like reducing single-use plastic consumption can help, the problem ultimately requires systemic solutions including stronger regulation of plastic production and improved waste management infrastructure. The United Nations Global Plastics Treaty negotiations, which are expected to conclude later this year, represent the most significant international effort to date to address plastic pollution at its source.
For now, the researchers say their findings underscore the urgency of understanding how microplastics affect human health and call for longitudinal studies tracking respiratory outcomes in populations with varying levels of microplastic exposure.
