Stelyus L. Mkoma

• Ph.D. in Chemistry
• Professor (Associate) at Sokoine University of Agriculture

Countless deleterious effects on human health and the environment are promoted by the action of air pollutants. Thus, it is necessary the development of analytical methods to identify and quantify efficiently ions present in atmospheric particulate matter. This study proposes a new analytical methodology for simultaneous quantification of 12 organi...

Objectives: This study aimed to determine the levels of Zinc and Copper, in human-, cow-and tinned baby-milk and canned baby foods marketed in Morogoro Municipal and intake of these mineral elements by infants. Methods: Human milk was collected from 41 mothers at different postpartum periods, cow milk was bought from dairy farms and infant formulas...

In this study, we present the hygroscopic behaviour of water soluble matter (WSM) extracted from biomass-burning derived PM2.5 aerosols collected at a rural background site in Tanzania during June-August 2011. Hygroscopic growth factors, g(RH), of WSM were measured by hygroscopic tandem differential mobility analyzer (H-TDMA) with an initial dry pa...

Tropical aerosols of PM2.5 and PM10 were collected at a rural site in Morogoro, Tanzania (East Africa), and analysed for stable carbon isotopic composition (δ13C) of dicarboxylic acids (C2-C9), glyoxylic acid (ωC2) and glyoxal (Gly) using gas chromatography/isotope ratio mass spectrometer. PM2.5 samples showed that δ13C of oxalic (C2) acid are larg...

Noise from milling machines and wood workshops found to be one of the major occupational hazards for the workers of industrial sector. The aim of this study was to assess the noise pollution and workers response towards noise effects in cereal milling machines and wood workshops in Tanga, Tanzania. A digital sound level meter was used to measure in...

The operation of airports results in environmental impacts associated with high levels of noises pollution. These may have severe negative effects to passengers, workers and surrounding residents. This study present assessed the aircraft noise levels at the Kilimanjaro International Airport (KIA) during landing and taking off. The perception and at...

The coastal atmosphere adjacent to large urban areas can be strongly affected by the emission of air pollutants, among them, major ions species. In this study, the chemical composition and sources of carboxylates and other water-soluble ions in fine and coarse aerosols as well as estimates of particle dry deposition fluxes were studied at a tropica...

In this paper, we report for the first time the delta C-13 and delta N-15 data for PM2.5 and PM10 aerosols collected in Tanzania during May-August 2011 together with total carbon (TC) and nitrogen (TN) contents. Mean TC concentrations were 6.5 +/- 2.1 mu g m(-3) in PM2.5 and 9.2 +/- 3.5 mu g m(-3) in PM10. delta C-13 of TC ranged from -26.1 to -20....

h i g h l i g h t s The use of fuel blend 95% petro diesel and 5% biodiesel by the heavy duty vehicles. Emissions profile of major ions from the combustion of biodiesel blend in real conditions. Low-molecular weight carboxylate and water-soluble inorganic ions. Chemical reactions occurred during fuel combustion until formation of carboxylate anions...

Atmospheric aerosol samples of PM2.5 and PM10 were collected in April-May 2011 from a rural site in Tanzania and analyzed for water-soluble inorganic ions and low molecular weight carboxylic acids using ion chromatography. PM2.5 and PM10 low-volume samplers with quartz fibre filters were deployed and aerosol collections on a 24 h basis were made fo...

Aerosol particles in the atmosphere consist of a mixture of naturally occurring materials and materials resulting from human activities. Levels of atmospheric particulate matter in most regions worldwide have been monitored during the past decade, mainly because of their effects on climate, human health and visibility. In some developing countries,...

This study examined students' attitudes towards physics and chemistry in selected secondary schools in Tarime-Mara, Tanzania. Three hundred (300) students in forms III and IV from six selected ordinary level secondary schools both private and government owned were involved in the study. Data were collected using validated reliable questionnaire and...

This study investigated students' understanding of particulate nature of matter using a model for relating microscopic processes to macroscopic changes in chemistry. The study was carried out at Mbalizi secondary school in Mbeya municipality and involved 375 students selected randomly from form II, III and IV. The students were presented with test...

Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania, East Africa, in 2011 during wet and dry seasons and were analysed for carbonaceous components, levoglucosan, mannosan and water-soluble inorganic ions. The contributions of biomass/biofuel burning to the organic carbon (OC) and particulate matter (PM) mass wer...

Atmospheric aerosol samples of PM 2.5 and PM 10 were collected during the wet and dry seasons in 2011 from a rural site in Tanzania and analysed for water-soluble di-carboxylic acids, ketocarboxylic acids, α-dicarbonyls, and fatty acids using a gas chromatography/flame ionization detector (GC/FID) and GC/mass spectrometry. Here we report the molecu...

This study aimed at identifying students' misconceptions about boiling point elevation, freezing point depression, and boiling and freezing temperature change (colligative properties) in high school chemistry. The study was carried out in Songea municipality in Tanzania and involved high school students taking chemistry as one of their subject comb...

Atmospheric aerosol samples of PM2.5 and PM10 were collected at a rural site in Tanzania in 2011 during wet and dry seasons and they were analysed for carbonaceous components, levoglucosan and water-soluble inorganic ions. The mean mass concentrations of PM2.5 and PM10 were 28.2±6.4 μg m-3 and 47±8.2 μg m-3 in wet season, and 39.1±9.8 μg m-3 and 61...

Atmospheric aerosol samples of PM2.5 and PM10 were collected during the wet and dry seasons in 2011 from a rural site in Tanzania and analysed for water-soluble dicarboxylic acids, ketocarboxylic acids, α-dicarbonyls and fatty acids using a gas chromatography (GC) and GC/mass spectrometry. Here we report the size distribution and sources of diacids...

Noise of machines in cement industries was found to be one of the major occupational hazards for the workers of industrial sector. The objectives of this study were to measure the noise levels in various production sections at a cement factory in Tanga, Tanzania and assess attitudes of workers towards noise health hazards. Noise levels were measure...

Traffic noise is a major environmental source of pollution both in developed and in developing countries. This study was carried out in Morogoro municipality, located about 200 km west of Dar es Salaam the business capital of Tanzania. Total of 16 measuring points were selected along main roads and A-weighted continuous equivalent sound level meter...

In this study, size-segregated particulate matter samples were collected in Raipur, India from July 2009 to June 2010 by using eight-stage cascade impactor sampler. The annual average concentrations and associated standard deviation of PM10, PM2.5–10, PM2.5, and PM1 were 270.5 ± 105.5, 119.6 ± 44.6, 150.9 ± 78.6, and 72.5 ± 39.0 μg/m3, respectively...

Aerosol particles in the atmosphere consist of a mixture of naturally occurringmaterials and materials resulting from human activities. Levels of atmospheric particulatematter in most regions worldwide have been monitored during the past decade, mainlybecause of their effects on climate, human health and visibility. In some developingcountries, suc...

People living in the large part of the African, Asian and Latin American continents often lack access to energy sources in general. One approach to provide these people with energy to increase living standards is to enable them produce energy from local resources. A promising local renewable energy source for people living in tropical regions is Ja...

This was an investigation to characterize seasonal and spatial distribution of particulate organic matter (POM) in the surface water of Lake Victoria at Speke Gulf, by using carbon-13 and nitrogen-15 isotopic signatures. Speke Gulf is under the influence of terrestrial inflow through river Simiyu. The POM from the lake surface water had higher C:N...

This paper reports the atmospheric concentrations of PM2.5 and PM1 mass, water soluble inorganic components and their seasonal variations measured between the period of July 2009 and June 2010 in Durg city (20°23' to 22°02'N and 80°46' to 81°58'E), India. A cascade impactor sampler with Whatman 41 glass filters was used to collect aerosol samples i...

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 sp...

This study elucidates the characteristics of ambient PM2.5 (fine) and PM1 (submicron) samples collected between July 2009 and June 2010 in Raipur, India, in terms of water soluble ions, i.e. Na+, NH 4+, K+, Mg2+, Ca2+, Cl−, NO 3− and SO 42−. The total number of PM2.5 and PM1 samples collected with eight stage cascade impactor was 120. Annual mean c...

The elemental composition of PM10 was studied during 2006 wet season in a rural background site of Morogoro, Tanzania. A Gent PM10 stacked filter unit sampler with coarse and fine Nuclepore polycarbonate filters, providing fine (0.4 μm) and coarse (8 μm) size fractions, was deployed. A total of 29 collections were analysed for the PM mass by weighi...

Few studies on a possible association between cooking fumes from different fuels and respiratory diseases other than cancer have been reported earlier. In the present study, an attempt was made to find out various respiratory symptoms in 360 kitchen workers using different cooking fuels. The study was conducted between October 2009 and March 2010 a...

This paper reports the atmospheric concentrations of PM 2.5 and PM 1 mass, water soluble inorganic components and their seasonal variations measured between the period of July 2009 and June 2010 in Durg city (20°23' to 22°02'N and 80°46' to 81°58'E), India. A cascade impactor sampler with Whatman 41 glass filters was used to collect aerosol samples...

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 indic...

Samples of coarse, fine and PM10 aerosols were collected at a rural Morogoro sites, during the 2005 dry season and 2006 wet season campaigns using a “Gent” PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters. A total of 80 aerosol samples were analyzed for water-soluble inorganic ions components using Ion Chromatography...

The assessment of the present status of sound levels in seven restaurants at Morogoro municipality was studied. The indoor and outdoor ambient noise levels were measured twice a day, thrice a week for a period of two months by using digital sound level meter. In addition, questionnaires survey was used to assess sources of noisepollution in restaur...

An intensive aerosol field campaign was carried out from 16 August to 16 September 2005 (dry season) at a kerbside in Dar es Salaam, Tanzania. A Gent PM10 stacked filter unit sampler with coarse and fine Nuclepore polycarbonate filters, providing fine (0.4 μm) and coarse (8 μm) size fractions, was deployed. A total of 64 parallel collections were m...

Atmospheric aerosol samples in PM10 and PM2.5 size fractions were collected in parallel at a rural site in Morogoro during wet season in March and April 2006. All samples were analysed for the particulate matter mass, for organic, elemental, and total carbon (OC, EC, and TC), and for water-soluble OC (WSOC). The average PM10 and PM2.5 mass concentr...

High levels of noise in hospitals may interfere with patient care services, the doctor-patient relationship and medical education activities. This study aimed to assess the noise level on wards in Iringa regional hospital and identify the noise sources. Sound levels were recorded in all wards in the hospital using a Digital Sound Level Meter. The m...

Ambient daytime and nighttime PM(10) and PM(2.5) samples were collected in parallel at a kerbside in Dar es Salaam in August and September 2005 (dry season) and in April and May 2006 (wet season). All samples were analyzed for the particulate matter mass, for organic, elemental, and total carbon (OC, EC, and TC), and for water-soluble OC (WSOC). Th...

The ionic composition of coarse, fine and total PM10 was investigated in aerosol samples collected from a kerbside in Dar es Salaam during the 2005 dry season and 2006 wet season. A “Gent” PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters, providing coarse (8μm) and fine (0.4μm) size fractions, was deployed. The mean...

An intensive aerosol field campaign was carried out from 11 July to 11 August 2005 (dry season) at a rural site in Morogoro, Tanzania. The objectives were to determine the chemical composition of the atmospheric particulate matter (PM) and to examine to which extent the gravimetric PM mass can be explained by the measured aerosol components. Two lo...

Ambient daily PM10 aerosol samples were collected at two sites in Tanzania in May and June 2005 (during the wet season), and their chemical characteristics were studied. The sites were a rural site in Morogoro and an urban kerbside site in Dar es Salaam. A Gent PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters, provid...

Three aerosol sampling campaigns were conducted at two sites (i.e., Dar es Salaam and Morogoro) in Tanzania, during different seasons from May 2005 through May 2006. A Gent PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters, providing coarse (2-10 µm diameter) and fine (<2 µm) size fractions, and PM2.5 and PM10 tandem...

Size-segregated aerosol samples were collected continuously from July 2009 to June 2010 at urban area of Raipur, the eastern central India. The collected samples were analyzed for PM 10 mass and its water-soluble dicarboxylate species and major inorganic ions. Results showed that the annual mean PM 10 concentration was 270.5 µg/m 3 , which varied f...