Microplastics can be found everywhere, from cosmetics to food to textiles. And now a new study has shown that the consumption of these tiny particles of plastic in the air could cause significant damage to human health.
A new review of nearly 3,000 studies—published last month in the Environmental Science and Technology— offers a comprehensive and troubling snapshot of how these microplastics affect digestive, reproductive and respiratory health.
Specifically, the study authors found that there is a suspected link between breathing microplastics and colon cancer, fertility problems in both men and women, and worsening lung function, which increases the risk of lung cancer.
Microplastics are tiny plastic particles that range in size from a pencil eraser (5 millimeters) to just one nanometer (a human hair is 80,000 nanometers wide, for scale), according to the US Environmental Protection Agency (EPA).
These harmful materials come from the nearly 460 million metric tons of plastic the world produces annually—a number expected to nearly triple by 2060.
This research is a sobering wake-up call, said the study’s lead author Dr. Nicolas Chartressenior research fellow at the University of Sydney and fellow at the University of California, San Francisco Program on Reproductive Health and the Environment.
In recent years, there has been a flurry of new research on the impact of microplastics on human health, and this review essentially “makes sense of everything,” he said.
“We understand there are digestive, respiratory and reproductive effects (from microplastics),” Chartres said Health. “When we inhale, consume seafood or drink water, this microplastic enters our body, our respiratory system, our digestive tract.
This new review expands on a report Chartres and colleagues contributed last year that documented the known health effects of microplastics and urged California lawmakers to explore further legislation to protect people from exposure to microplastics.
Chartres and his colleagues looked at nearly 3,000 recently published studies that made claims about the health effects of microplastics.
They considered the quality of each study’s evidence and the overall strength of their findings. Most of the studies included in the review were done on animals.
Based on the quality of each study, the authors classified links between exposure to airborne microplastics and certain health problems as “known,” “presumed,” “suspected,” or “unclassifiable.”
In the end, they concluded that microplastics are “suspected” of harming people’s reproductive, digestive and respiratory health. They also noted a possible link with colon cancer.
Although most of the studies were done on animals — especially rodents — Chartres explained that the findings are still applicable to humans, since both humans and animals are subject to similar exposures, he said.
A large-scale review of this kind is relatively new, and the findings highlight “the fact that there is kind of an almost ubiquitous impact on our health from these (microplastics),” he said. Marie Johnson, MD, PhDresearch scientist in the Department of Environmental Health at the Harvard TH Chan School of Public Health.
“We’re only at the tip of the iceberg” in our understanding of how widespread these negative health effects can be, Johnson said. Health.
Given how small and common these materials are, it’s not always easy to measure a person’s exposure to microplastics and the various chemicals that can accompany them, Johnson said.
“Microplastics contain not only plastic polymers, but also chemicals that have been added to the plastic,” she explained. “They probably change the toxicity and the level of exposure, but we’re just not far enough along in the research to be able to draw any conclusions.”
Although measuring exact amounts can be challenging, experts agree that microplastics are all around us. They are used intentionally in cosmetics, packaging, tires, paints, synthetic fabric and more, but they have also been found in human tissue, food, drinks and air.
For the purposes of the new review, the authors focused on these airborne particles. Because the particles are airborne, these microplastics are found “in the most remote locations in the world,” Chartres said.
There are numerous ways these tiny pieces of plastic can become airborne, including sea spray, textiles found in landfills interacting with the wind, tires degrading as people drive, and more.
Wildfire smoke is another common way people inhale microplastics, Johnson said. As the fires sweep through cities with modern, prefabricated homes, they burn and spread microplastics into the air.
There are other routes of exposure.
Microplastics are abundant in our oceans and waterways, contaminating the fish and seafood we consume, Johnson said. We can even come into contact with these particles through skin absorption, she added, although this is the least common method of exposure.
Due to the ubiquity of microplastics, all people are at risk, said Chartres. Microplastics travel through air, water, our food — it’s impossible to avoid.
These materials also “bioaccumulate” once they enter a person’s body, pooling in tissue and staying there over time, he said. The amount of microplastic in a person’s body increases the longer it is exposed.
That being said, certain factors can influence who is most affected by exposure to microplastics. Some people living with various other conditions might be more prone to lung problems or various types of cancer, for example.
Similarly, social determinants of health may come into play. People of lower socioeconomic status, those in low- and middle-income countries, and people in certain professions may be more exposed to air pollution or more likely to consume food wrapped in plastic, Chartres said. They could see higher levels of exposure.
“Socioeconomic factors such as poverty can contribute to greater stress on the body. “They can exacerbate the damage from chemical exposure,” he said. “People who experience more external and internal stressors may have more damage from exposure to the body (from microplastics).”
Unfortunately, avoiding microplastics is not an easy task. And that’s a tough conversation, Chartres said.
Long-term damage has been done — these materials cannot be removed from our atmosphere, oceans, or soil, and much of the American food system relies on plastic packaging.
That being said, people can monitor their food sources and try to eat “as much fresh produce as possible,” he recommended.
This review and others like it should be a warning to both regulators and ordinary people, Chartres said.
“We’re seeing three times the projected production of plastic over the next 30 years – all that degraded plastic in the environment will be exposed in our air, food and water,” he explained.
For the average consumer, it’s important to “be more aware of what they’re buying,” Johnson said.
“One good example is synthetic clothing – I wouldn’t have thought twice about buying synthetics over cotton before,” she said.
“The most important part is engaging people to really ask questions, no matter where you are in the world,” added Chartres.
Government action and larger structural changes are also key.
“Banning non-essential use of plastics is one way (to reduce exposure to microplastics),” Chartres said. “Requiring governments to examine the data from these studies to (inform) sufficient regulation is another.”
Another avenue, Johnson said, could be legislation that makes non-synthetic textiles and products more affordable and accessible to consumers.
We can’t “turn off the tap” when it comes to plastic production, but “the overwhelming message, globally, is that there is an opportunity to take timely action now,” Chartres said.
“The successful regulation of industries like tobacco shows that governments will be responsive when it comes to the relationship between products and chemicals,” he said. “If we don’t respond to this, the consequences in the next 20 to 30 years (will be) devastating.”