Introduction: Microplastics (MPs) and nanoplastics (NPs) have garnered increasing attention due to their widespread presence in the environment and potential implications for human health. While MPs typically measure less than 5 mm in diameter, NPs are even smaller, ranging between 1 and 100 nm. These particles, collectively termed nano- and microplastics (NMPs), originate from both intentional manufacturing processes, such as cosmetics and personal care products, and the degradation of larger plastic items like water bottles and clothing.
Background: Respiratory exposure to small particles, whether from smoke, chemical combustion products, or dust, poses significant public health risks, leading to lung injuries and increased mortality rates. Recent studies have identified NMPs within the human respiratory tract, from the nasal cavity to the lower airways, highlighting concerns about their potential health impacts. Both humans and wildlife, including avian populations, face exposure to airborne plastics, raising legitimate concerns about respiratory health.
The interaction between NMPs and human lung cells suggests a link between plastic exposure and respiratory disorders such as chronic obstructive pulmonary disease, fibrosis, dyspnea, asthma, and the formation of frosted glass nodules. To understand the dynamics of NMPs within the respiratory system, computational fluid-particle dynamics (CFPD) offers a promising approach. While previous research has applied CFPD to various environments, including water bodies and turbulent flows, there's a notable gap in understanding NMP behavior within the respiratory system.
Objective: Building upon previous work, this study aims to predict the transport and deposition (TD) behavior of spherical, cylindrical, and tetrahedral NMPs within a full respiratory tract model under realistic breathing conditions. Utilizing a poly-disperse methodology, particles ranging from 1 to 100 nm for NPs and 1 to 100 μm for MPs are considered. The comprehensive model spans from the nasal cavity to the 13th generation of the bronchial tree, incorporating experimentally measured respiration volume flow rates to simulate slow, middle, and fast breathing scenarios.
Key Highlights:
- Comprehensive Model: Encompasses the entire human respiratory tract, providing detailed insights into NMP deposition patterns.
- Poly-disperse Methodology: Considers a wide range of particle sizes to mirror real-world scenarios.
- Realistic Breathing Conditions: Incorporates experimentally measured respiration volume flow rates to simulate various breathing scenarios.
- Implications for Health and Environment: Offers insights into the potential health impacts of NMP exposure and contributes to understanding NMP-related air pollution.
Conclusion: By elucidating the behavior of NMPs within the human respiratory system, this study provides valuable insights for regulatory frameworks, medical interventions, and environmental management strategies. Understanding NMP deposition patterns and their implications for respiratory health is crucial for mitigating associated risks and safeguarding public health and the environment.
Source: https://www.sciencedirect.com/science/article/pii/S2666765724000437?via%3Dihub