Determination of Air Pollutants Concentration from Ground Level Sources in Abuja Metropolis, Nigeria.

Abstract

This work focuses on measurements of concentration of gaseous emissions such as CO, S₂O H₂S and  particulate matters (PM₁₀ and PM_2.5 ) released from ground level sources at specified receptor points downwind.  These sources were monitored using Altair Multi-gas and HAT 200 PM₁₀ and PM_2.5 detectors. From the selected sources monitored, Carbon Monoxide had the highest dispersion strength of 45%. An analysis of the concentrations show that refuse burning source has maximum concentrations of 111.2 mgm^-3 for CO, 7.312 mgm^-3 for SO₂ , 5.342 mgm^-3 for H₂S, 0.542 mgm^-3 for PM₁₀ and 0.272 mgm^-3 for PM_2.5 respectively while  minimum concentrations of 77.42 mgm^-3 for CO, 0.52 mgm^-3 for SO₂ , 1.44 mgm^-3 for H₂S, 0.48 mgm^-3 for PM₁₀ and 0.14 mgm^-3 for PM_2.5 respectively were obtained from wood burning source. This shows that CO has the highest concentrations of the pollutants monitored. Correlation between modeled and measured concentrations showed that wood burning source has higher validity of the model with coefficients of regression R² for CO, SO₂ , H₂S, PM₁₀ and PM_2.5 as 0.885, 0.848, 0.574, 0.861 and 0.715 respectively while refuse burning has the least measure of validity with coefficients of regression R² for CO, SO₂ , H₂S, PM₁₀ and PM_2.5 as 0.363, 0.416, 0.416, 0.431, 0.572 and 0.284 respectively. Based on Ambient Air Quality Standards, refuse burning sources are most harmful of the sources investigated. A comparative environmental impact assessment of the sources reveals that they are unsafe for selected pollutants. For CO (1 hour time average, the safe limit is 40mg/m³), SO₂ (1 hour time average, the safe limit is 0.35040mg/m³) and H₂S (1 hour time average,  the safe limit is 0.04240mg/m³).