Inhaled Microplastics Collect in Human Airways

Researchers found that potentially harmful microplastics can gather in specific areas of the human respiratory system, which may pose a health risk.

Manufacturers use plastic in so many products it's challenging to find something not made of the material. Because of this, scientists say that microplastics are abundant in virtually every ecosystem, and humans carry a certain amount of this microscopic plastic in their bodies.

For instance, research suggests that a person inhales enough microplastic every week to equal a credit card.

Plastic contains a wide range of chemicals, which may pose serious health risks. Though scientists know microplastics are in human airways, how they travel through the respiratory system is unclear. Understanding this better could help prevent and treat microplastic-related respiratory diseases.

In a study published on June 13 in Physics of Fluids, researchers analyzed how microplastics are transported and deposited within the upper lung airways using a computational fluid dynamics model.

To conduct the research, the team examined the pathways that microplastics of differing sizes and shapes take in fast and slow breathing conditions.

They found that increased airflow rates led to less deposition of microplastics, and larger microplastics deposited in the airway more often than smaller particles.

Moreover, microplastics landed and collected more in the nasal cavity and the back of the throat.

In a news release, corresponding author Mohammad S. Islam explains, "The complicated and highly asymmetric anatomical shape of the airway and complex flow behavior in the nasal cavity and oropharynx causes the microplastics to deviate from the flow pathline and deposit in those areas."

The authors say these findings underscore the concern about exposure to microplastics in regions where plastic pollutants are high, such as industrial areas. In addition, study author YuanTong Gu says, "This study emphasizes the need for greater awareness of the presence and potential health impacts of microplastics in the air we breathe."

The authors say future research will look at the effects of microplastics in healthy and diseased lung models and different temperature and humidity conditions.