As of 2016, the Land Transport Authority (LTA) of Singapore reported that there was a total number of 956,430 motor vehicles in Singapore. Motor vehicles are a major source of pollution as incomplete combustion of engine fuel leads to the formation of harmful pollutants which is detrimental to the health of individuals and the environment. Due to the large volume of vehicles in the country, there is a need to convert these harmful pollutants into non-harmful substances to ensure a safe environment. It is crucial that we understand the impact pollutants have on air quality and the role of the catalytic converter in converting these pollutants to harmless substances.
The highest NOx emissions are generally found in states with large urban areas, high population density, and heavy automobile traffic. Therefore, it is not surprising that the highest levels of atmospheric NO2 are measured over Los Angeles County, the car capital of the country.
References:
“MOTOR VEHICLE POPULATION BY VEHICLE TYPE” <https://www.lta.gov.sg/content/dam/ltaweb/corp/PublicationsResearch/files/FactsandFigures/MVP01-1_MVP_by_type.pdf> (accessed Mar 26, 2017).