What is the primary source of carbon monoxide emissions?

The primary source of carbon monoxide emissions is the incomplete combustion of carbon-containing fuels. This occurs when there is not enough oxygen available for the fuel to burn fully. During complete combustion, carbon dioxide is primarily produced, which is much less harmful to health and the environment compared to carbon monoxide. However, in situations where combustion is not fully complete—such as in enclosed spaces with insufficient airflow—carbon monoxide is formed instead. This gas is highly toxic because it binds to hemoglobin in the blood more effectively than oxygen, thus preventing the transport of oxygen throughout the body. Incomplete combustion can happen in various everyday scenarios, such as in car engines, home heating systems, and cooking appliances, making it a significant concern for indoor and outdoor air quality.