Microplastic pollution was first discovered deep in the lungs of living people. The particles were found in almost all samples analyzed.
Scientists said microplastic pollution is now ubiquitous on the planet, making human exposure inevitable and meaning “there is growing concern about the risks” to health.
Samples were taken from tissue taken from 13 patients undergoing surgery and microplastics were found in 11 cases. The most common particles were polypropylene, used in plastic packaging and pipes, and PET, used in bottles. Two previous studies had found microplastics at similarly high levels in lung tissue taken during autopsies.
People were already known to breathe in the tiny particles, as well as consume them through food and water. Workers exposed to high levels of microplastics are also known to have developed illnesses.
Microplastics were detected in human blood for the first time in March, showing that the particles can travel through the body and lodge in organs. The health impact is still unknown. But researchers worry because microplastics damage human cells in the lab and air pollution particles are already known to enter the body and cause millions of premature deaths a year.
“We didn’t expect to find the greatest number of particles in the lower regions of the lungs, or particles of the sizes we found,” said Laura Sadofsky of Hull York Medical School in the UK, author principal of the study. “This is surprising because 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 reaching this depth.”
“These data are an important advance in the area of air pollution, microplastics and human health,” she said. The information could be used to create realistic conditions for laboratory experiments to determine health impacts.
The research, which has been accepted for publication by the journal Science of the Total Environment, used samples of healthy lung tissue alongside surgical targets. It analyzed particles down to 0.003mm in size and used spectroscopy to identify the type of plastic. He also used control samples to account for the level of background contamination.
A 2021 study in Brazil of autopsy specimens found microplastics in 13 of 20 people analyzed, whose average age was older than those assessed by Sadofsky’s study. Polyethylene, used in plastic bags, was one of the most common particles. The researchers concluded, “Adverse health effects may be related to…these contaminants in the respiratory system after inhalation.
A US study of lung cancer patients in 1998 found both plastic and plant fibers (like cotton) in more than 100 samples. In the cancerous tissues, 97% of the samples contained fibers and in the non-cancerous samples, 83% were contaminated.
Huge amounts of plastic waste are being dumped into the environment and microplastics are now contaminating the entire planet, from the summit of Mount Everest to the deepest oceans. Microplastics have been found in the placentas of pregnant women, and in pregnant rats they quickly travel through the lungs to reach the heart, brain and other organs of fetuses.
A recent review assessed cancer risk and concluded: “More detailed research into how micro- and nanoplastics affect structures and processes in the human body, and if and how they can transform cells and induce carcinogenesis , are urgently needed, especially in light of the exponential increase in plastic production.