The CO level for each of the three sampling sites was measured simultaneously using the portable carbon monoxide detector (model: DSM8922) by standing the monitor at a height of about two to three meters above the ground level considering the average human height. The monitoring of CO for residential areas was done in two consecutive periods per day, that is morning (7:00am -9:00) and evening (4:00pm -7:00pm) daily for (3) days within the week Monday and Tuesday for day 1, Wednesday, Thursday and Friday for day 2 while Saturday and Sunday are for day 3. These days were chosen for residential areas due to the activities always carried out in such regions like schooling, church, ceremonies and others. The morning and evening average measurements for each day will be obtain by monitoring thirty minutes log intervals recording between 7.00-9.00am and 4.00 -7.00pm for morning and evening measurements respectively