What is a primary source of Nitrogen Dioxide?

Nitrogen dioxide (NO2) is primarily produced through the combustion of fossil fuels, making the first choice the correct answer. This gas is commonly released during processes such as burning coal, oil, and natural gas for energy and transportation.

When fossil fuels combust, various nitrogen-containing compounds in the fuel react with oxygen, leading to the formation of nitrogen oxides, including nitrogen dioxide. This is particularly significant in urban areas where vehicles and industrial activities contribute to higher emissions.

While decomposing organic matter and exhalation from living organisms can release various gases, they do not significantly contribute to the levels of nitrogen dioxide found in the atmosphere. Decomposing organic material tends to generate substances like ammonia and methane, and while living organisms do exhale nitrogen compounds, the volumes and chemical pathways involved are small compared to combustion processes.

Natural gas emissions can contribute to nitrogen oxide levels, but this is a more indirect source. The primary emissions of nitrogen dioxide primarily arise from combustion processes associated with fossil fuels rather than from natural gas alone.