In recent years, the problem of microplastic pollution has become increasingly serious and may become a hidden danger affecting human health. Generally speaking, microplastics refer to plastic particles less than 5 mm in diameter and are a major carrier of pollution. In fact, the particle size of microplastics ranges from a few microns to several millimeters. They are a mixture of non-uniform plastic particles with various shapes, which are often difficult to distinguish with the naked eye. They are vividly called “PM2.5 in the sea”. To this end, an international research team developed a computational fluid dynamics model to analyze the trajectory and adhesion of microplastics in the human respiratory tract. Research shows that the amount of microplastics humans inhale every week is probably equivalent to inhaling a credit card.
The researchers pointed out that microplastics are more likely to accumulate in an area at the back of the nose and throat called the oropharynx, and that the size of the microplastics and the way people breathe will affect the amount of microplastics that stick to the respiratory tract. For example, when breathing faster, microplastics adhere less, and larger microplastics are more likely to stick to the respiratory tract than smaller microplastics.
Last year, scientists discovered microplastics deep in the human respiratory tract for the first time. Because microplastics often contain pollutants and chemicals, understanding how they spread in the respiratory tract is critical to preventing and treating respiratory diseases.