What are the effects of acute exposure to nitrogen dioxide?

Acute exposure to nitrogen dioxide (NO2), a reddish-brown gas with a characteristic sharp, acrid odor, can lead to significant respiratory issues. One of the primary effects of direct exposure to nitrogen dioxide is severe lung irritation, which may manifest as difficulty breathing, coughing, and a sensation of tightness in the chest. This is due to the gas's ability to cause inflammation and irritation of the respiratory tract upon inhalation.

Additionally, fresh exposure to NO2 affects the olfactory system, which is responsible for the sense of smell. High levels of nitrogen dioxide can lead to a temporary reduction in the ability to smell, known as reduced olfactory function. This effect is important because it diminishes the body's natural response to hazardous conditions, as individuals may not be able to detect the presence of the gas based on smell alone after exposure.

Other options describe symptoms that may apply to various conditions or exposures, but they do not accurately reflect the specific and significant effects associated with acute nitrogen dioxide exposure, which centers on severe lung irritation and impacts on the olfactory system.