Every breath you take could be full of invisible plastic particles invading your body. Now, scientists in Australia know where this plastic pollution is building up in our bodies.
A groundbreaking study by a team at the University of Technology Sydney reveals a concern far more intimate and invisible than smog or smoke: microplastics and nanoplastics, tiny particles that regularly infiltrate the human respiratory tract. These findings, documented in the journal Environmental Advances, could have significant implications for public health.
First, we need to break down what exactly is entering the human body. Microplastics are tiny plastic fragments, less than five millimeters in size, often from the breakdown of larger plastic waste. Nanoplastics are even smaller, measuring between one and 100 nanometers. Both can be released into the environment from a variety of sources, including cosmetics, clothing, and larger plastic debris.
The study utilized advanced computational fluid particle dynamics (CFPD) to track how these tiny pollutants move through and deposit within our respiratory systems. Imagine particles so small that they can travel through the air we breathe and settle deep within our lungs, potentially causing or exacerbating a range of respiratory ailments, from asthma to chronic obstructive pulmonary disease (COPD).
The researchers built a detailed model of the human respiratory tract — from the nose to the bronchial tree’s 13th generation — based on computerized tomography scans. This allowed them to observe how different sizes and shapes of plastics behave under different breathing conditions: slow, normal, and fast breathing. What emerges is a vivid picture of our lungs under siege by plastics.
For instance, larger microplastics, due to their size and the body’s airflow dynamics, tend to deposit in the upper respiratory tract. This is similar to how larger, visible dust particles might get caught in your nose or throat.
Meanwhile, the tinier nanoplastics, thanks to their minuscule size and the effects of Brownian motion (the random movement of particles in fluid), can penetrate deeper into the lungs, reaching the delicate bronchioles and alveoli where gas exchange occurs. This could potentially lead to more direct impacts on lung tissue.
“Experimental evidence has strongly suggested that these plastic particles amplify human susceptibility to a spectrum of lung disorders, including chronic obstructive pulmonary disease, fibrosis, dyspnea (shortness of breath), asthma, and the formation of what are called frosted glass nodules,” says Dr. Suvash Saha in a university release. “Plastic particle air pollution is now pervasive and inhalation ranks as the second most likely pathway for human exposure.”
The study’s simulations showed distinctive patterns in how these particles deposit, depending on the breathing rate. Under fast breathing—like when you’re running—particles are deposited more in the upper airways. Slow, deep breaths, which might occur during sleep, allow particles to settle deeper into the lungs. This is critical to understand because it indicates that our exposure level and potential health risks might vary throughout the day and with different activities.
“Particle shape was another factor, with non-spherical microplastic particles showing a propensity for deeper lung penetration compared to spherical microplastics and nanoplastics, potentially leading to different health outcomes,” Dr. Saha adds. “These findings highlight the imperative consideration of breathing rates and particle sizes in health risk assessments associated with respiratory exposure to nano and microplastic particles.”
Source: https://studyfinds.org/every-breath-you-take-plastics/