Final answer:
Thick, black smoke in a compartment poses a threat to life mainly because it results in a limited supply of oxygen, along with the introduction of toxic substances like carbon monoxide that can replace oxygen in the blood.
Step-by-step explanation:
Thick, black smoke in a compartment reduces the chance of life sustainability due to limited oxygen supply. When the air is full of smoke, there is less room for oxygen, which is essential for cellular respiration and life. Additionally, smoke inhalation commonly brings with it a host of toxic substances, including carbon monoxide (CO) and other dangerous gases. Carbon monoxide, for instance, can quickly lead to death as it replaces oxygen in the bloodstream, preventing it from reaching vital organs. Moreover, compounds found in smoke, such as carbon particles, can severely impact breathing by reducing the surface area available for gas diffusion, leading to a decrease in oxygen levels in the blood and an increase in carbon dioxide levels. This can result in suffocation, toxic effects on the body, and aggravation of respiratory conditions such as COPD.