Final answer:
Particles between 1-5 micrometres (mcm) affect the deeper regions of the lungs, such as the alveoli, and can cause respiratory diseases like pneumonia, bronchitis, and asthma by evading protective mechanisms and penetrating lung tissues.
Step-by-step explanation:
The part of the respiratory system affected by particles between 1-5 micrometres (mcm) is the deeper regions of the lungs, including the alveoli. These particles are small enough to bypass the protective mechanisms such as nasal hairs and mucus found in the upper respiratory tract, allowing them to penetrate into the innermost parts of the respiratory system. Pollutants of this size range, often referred to as PM2.5, can cause respiratory diseases such as pneumonia, bronchitis, asthma, and other conditions by interfering with the gas exchange process in the alveoli and causing inflammation or other damage to the lung tissue.
Individuals can take certain measures to protect their respiratory health, such as avoiding smoking and reducing exposure to polluted air. The respiratory system also has its own set of protective features, like the mucociliary escalator, to combat these foreign particles and minimize potential damage. However, the fine particulate matter (1-5 mcm) still presents health risks due to its ability to deeply penetrate lung tissues.