Particle Counts and Size Distributions in Local Garri Processing Environment

Previous studies have linked morbidity and mortality of individuals to airborne particles resulting from anthropogenic sources. Fine particles (particles < 2.5 µm) are known to have harmful effects on human health and environment compared to the coarse particles (2.5 µm < dp <10 µm). Sadly, developing countries experiencing rapid growth are characterized with inadequate environmental action and policy. Garri processing has been linked to contribute to ambient particulate matter pollution. The present study investigates the number and sizes of particulate emitted as a result of this anthropogenic activity. Continuous measurement of number concentration and size distributions of particles of diameters 0.3 µm, 0.5 µm, 1.0 µm, 2.0 µm and 5.0 µm were conducted, using a GT -321 particle counter for day and night cases November 2012 at four major local garri processing locations in the ancient city of Oyo, Nigeria. On the average, the total particle number concentration for the selected four locations were 2.3 × 106 – 8.9 × 106 ; 0.085 × 106 – 4.487 ×106; 0.073 × 106 – 0.912 × 106; 0.022 × 106 – 0.654 × 106; and 0.002 × 106 – 0.155 × 106 for particle size 0.3µm, 0.5 µm, 1.0 µm, 2.0 µm and 5.0 µm respectively for day time readings and 1.021 × 106 –8.793 × 106; 0.071 × 106 – 3.323 × 106; 0.051 × 106 – 1.903 × 106; 0.012 × 106 – 0.278 × 106;and 0.003 × 106 – 0.015 × 106 for particle size 0.3µm, 0.5 µm, 1.0 µm, 2.0 µm and 5.0 µm respectively for night time measurements. Daily cycle of particle numbers were obvious with high concentrations recorded during day time but lower level at night time which is consistent with the trend of the garri processing activity. The findings suggested that higher fraction of fine particles (0.3 - 2 µm) are produced and retained in the ambient air from this activity. Keywords: Garri, number concentration, size distribution, particulate matter