Nitrogen dioxide is one of the criteria air pollutants that plays an important role as a precursor gas of fine particulate matter and ozone. NO2 emissions are known to be primarily generated by industrial facilities or vehicle exhausts. Recently, a research team from POSTECH analyzed satellite remote sensing data from the European Space Agency (ESA) and released results showing that food processing facilities and high-rise apartments that are 10 stories or higher are significant sources of NO2 emissions. Their findings have drawn attention from NASA.