Which of the following gases is naturally produced and contributes to respiratory distress?

The correct answer is that all of the gases listed can naturally contribute to respiratory distress. Carbon dioxide is a normal byproduct of metabolism and is found in the atmosphere. While it is not typically harmful at the levels found in the environment, excessive concentrations can lead to respiratory issues, particularly in enclosed spaces where ventilation is poor.

Nitrogen dioxide is a significant air pollutant, often arising from combustion processes, such as those in vehicles and industrial activities. It can irritate the lungs and lower immunity to respiratory infections, making it particularly dangerous for those with existing lung conditions.

Ozone, while beneficial in the upper atmosphere as a protective layer against ultraviolet radiation, is harmful at ground level. It can be produced naturally through various atmospheric reactions, especially during sunny days with high levels of sunlight. Ground-level ozone is a powerful respiratory irritant and can exacerbate asthma and other chronic respiratory diseases.

Understanding each of these gases highlights their respective roles in air quality and public health, illustrating how they can contribute to respiratory distress under certain conditions.