Browsing by Author "Mkoma, Stelyus L."

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Dependence of air quality on meteorological parameters in Dar es Salaam, Tanzania
(Tanzania Journal of Natural and Applied Sciences, 2010) Mkoma, Stelyus L.; Kimambo, Offoro N.; Mabiki, Faith P.; Tungaraza, Clavery T.
The influence of meteorology on air quality in Dar es Salaam was investigated. Precipitation, temperature, relative humidity and wind speed were measured during wet and dry seasons of 2005 and 2006 period and their relationship with reported mass of particles of aerodynamic diameter smaller than 10 μm (PM10) for the site was assessed. Results indicate that the highest median concentrations for the PM10 mass (58 μg/m 3 ) was observed during the 2005 dry season and the lowest median (40 μg/m 3 ) during the 2006 wet season. It is interpreted that reasons for the higher levels of the PM10 mass in the dry season are due to temperature inversions, soil dust dispersal and absence of rain wash-down. The observed PM10 levels are also affected by the variations in sources strengths and in meteorological conditions such as mixing height, precipitation, relative humidity, wind speed and direction as supported by air mass trajectories.
Influence of meteorology on ambient air quality in Morogoro, Tanzania
(International Journal of Enviromental Science., 2011-03) Mkoma, Stelyus L.; Mjemah, Ibrahimu C.
The influence of meteorological parameters on air quality was investigated for a rural background site in Morogoro. Precipitation, temperature, relative humidity and wind speed were measured during wet and dry seasons of 2005 and 2006 period and their relationship with reported mass of particles of aerodynamic diameter smaller than 10 μm (PM10) for the site was assessed. The results show that higher PM10 mass concentrations (45μg/m 3 ) were obtained during the 2005 dry season and the lowest (13 μg/m 3 ) during the 2006 wet season. It is interpreted that reasons for the higher levels of the particulate matter mass in the dry season are due to temperature inversions and absence of rain washdown. The observed particulate matter levels are also affected by the variations in sources strengths and in meteorological conditions such as mixing height, precipitation, relative humidity, wind speed and direction as supported by air mass trajectories.
Nitrate pollution of Neogene alluvium aquifer in Morogoro Municipality, Tanzania.
(International Formulae Group, 2011-02) Kibona, Irene; Mkoma, Stelyus L.; Mjemah, Ibrahimu C.
Concern over nitrate pollution of groundwater in integrated water quality management has been growing recently. The levels of nitrate in wells from septic tanks and urban agriculture with nitrogen fertilizers application may increase the potential groundwater pollution by nitrate. The purpose of this study was to determine the concentrations and spatial distribution of nitrate (NO 3 − ) in groundwater in Morogoro Municipality. Groundwater samples were collected from 20 wells during wet season period in March-April 2010 in 6 wards namely Kihonda, Mji Mpya, Mafisa, Saba Saba, Boma and Kilakala. The spectrophotometer was used to measure the NO 3 − concentration in water samples. The minimum and maximum nitrate levels were 1.4 and 32.5 mg/L respectively in the wards studied with an average of 7.76 mg/L. These results showed that all of the groundwater samples have NO 3 − concentration below the Tanzania Bureau of Standards upper limit value and World Health Organization guideline of 75 mg/l and 50 mg/l respectively. Also, the level of nitrate concentration tend to decrease with depth for most of the places due to the anoxic condition that is available at the higher depth which facilitates the utilization of nitrate by anaerobic microorganisms.