Air pollutions pollutant showed that the extent of spreading depends on the motor vehicle traffic population of the area. This pollution strongly generated through combustion of fossil fuels presents difficult environmental challenge to societies as it could degrade the environment and affect human health and quality of life. Vehicular emissions are major contributors to air pollution in urban areas as they contain harmful gases. The levels of carbon monoxide has been investigated in two locations of Enugu metropolis (high traffic ‟old park‟ and low traffic „caritas university‟), in order to determine its pollution status with regards to air. EL-USB-CO analyzer used for the analysis indicated variations in the levels of CO for the period of study. The results obtained revealed that the concentrations of CO in high traffic (HT) area is higher than that of low traffic (LT) and is unacceptable compared with the Federal Environmental Protection agency (FEPA) Nigeria set limit. The dispersion pattern of the suggests that vehicular emission contributes to the levels of carbon monoxide in the environment.

Air pollution is associated with increasing cases of many adverse health effects, e.g. mortality, respiratory diseases and cancer. The chemical composition of ambient air is very complex and depends on many different factors, traffic generated air pollution being a major source in large cities. This is especially true in the developing world, mainly due to the high proportion of old, poorly maintained vehicles, the abundance of two stroke vehicles and the poor fuel quality (Baumbach et al., 1995; Gwilliam 2003). All these factors contribute to one of the major air pollutant in urban areas; carbon monoxide (CO).

CO is a poisonous, colorless, inevitable gas that has neither taste nor smell. It is formed when carbon burns with too little air (incomplete combustion) (Smith and Scott, 2002). Carbon monoxide (CO), also called Carbonious oxide or Carbon (II) Oxide and is slightly lighter than air. CO is a deadly, colorless, odorless, poisonous gas, produced by the incomplete burning of various fuels, including coal, wood, charcoal, oil, kerosene, propane, and natural gas. Products and equipments and machines powered by internal combustion engines such as portable generators, cars, lawn mowers, and power washers also produce CO. It has a high affinity for hemoglobin in blood and displaces O2 to form carboxyl hemoglobin (COHb). This can cause dizziness, headaches and eventually death.