MODELLING THE DISPERSION OF AIRBORNE PARTICULATES EMISSIONS FROM OPEN BURNING OF A MUNICIPAL WASTE DUMPSITE IN PORT HARCOURT, NIGERIA

Abstract

This study examined the impacts of burning municipal solid wastes (MSW) in Port Harcourt. The emission factor technique and AERMOD model were used to quantify and determine dispersion of particulates emissions released during the burnings of the unsegregated wastes. The particulates emissions from the site were as follows: 2,247.9 tons/year (PM2.5); 6,881.4 tons/year PM10 and 1,261.6 tons/year for black carbon (BC). The average 1-hour wet and dry season ground level concentrations for PM2.5, PM10 and BC were within the following range: 3.4- 3352 μg/m3 10.3-10577.3 μg/m3 and 1.9-1966.6 μg/m3. The highest particulates emissions ranges exceed the hourly Nigerian acceptable limit by over 700 %. The areas of high/low impacts for both wet and dry seasons were in the northeast, east, southeast/southern, south-western, western, north-western directions with most impacted radius of the dumpsite from 0-6 km. The lower atmosphere stability profile revealed that particulates dispersion will be severe during the periods of dawn due to stable nature of the boundary layer atmosphere. Increased levels of airborne particulates in the air are associated to health hazards such as heart disease, altered lung function and lung cancer. Policy Makers should make certain that needless burnings of MSW at open dumpsites are curtailed with adequate separation of inorganic and organic wastes. This will be achieved by providing proper incineration mechanism to burn unsegregated organic and inorganic MSW