
The quality of ambient air in Aba metropolis, a commercial city in Abia State of Nigeria has been assessed by determining the levels of Total particulate matter (TPM), Carbon (II) Oxide (CO), Nitrogen (IV) Oxide (NO2), Sulphur (IV) Oxide (SO2), Hydrogen (II) Sulphide (H2S), and Methane (CH4) at ten different sampling points. The analysis was carried out between the months of July and August 2011, and a Crowncom portable gas analyzer was used for each of the determinations. The mean values obtained for CO, NO2 and H2S exceeded the standard regulatory limits (EPA and NAAQS) in all the sample points with the exception of the control point. The study showed that there is need for the control and monitoring of ambient air in Aba metropolis by the relevant agencies.