What is a notable risk factor for the development of PE?

Long-distance travel is a well-documented risk factor for the development of pulmonary embolism (PE). During prolonged periods of immobility, such as sitting for extended hours on a plane or in a car, blood flow in the lower extremities can become stagnant, leading to the formation of deep vein thrombosis (DVT). If a DVT breaks free, it can travel to the lungs and result in a PE. This risk is particularly heightened in individuals with other predisposing factors such as obesity, prior history of DVT or PE, or hormonal therapy.

The other options listed do not carry the same level of risk associated with PE. Regular exercise generally promotes good circulation and reduces the likelihood of venous thromboembolism, while high fluid intake is beneficial for overall cardiovascular health and helps to maintain blood viscosity. Similarly, low intake of dairy products does not directly correlate with an increased risk of PE. Thus, long-distance travel remains a significant and notable risk factor for this condition.