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2013

Kinyua, AM, Maina DM, MANGALA MJ, GATARI MJ.  2013.  Energy Dispersive X-Ray Fluorescence (EDXRF) in Non-Destructive Testing of Oil Samples. AbstractWebsite

A rapid non-destructive, multi-elemental and ultra-sensitive analytical technique of engine oil analysis is described. Using" an x-ray excitation source and Si(Li) detector for the1 measurements, the deterioration of an internal combustion engine) is evaluated from results of concentration levels of Ti, Ca, Mn, Cr, Fe, Cu, Zn, Pb and Br. Analysis of these elements from samples of new and used engine oil from a commercial brand showed significant increases in the levels of Fe(164%), Br(5022%) and Pb (65000%) after an engine had run a distance of 1103 km. No major increases were noticed for the other elements. The changes are due to the wear and tear of engine parts and subsequent contamination of the engine oil. The increase of Pb and Br is due to the leakage of exhaust fuel gases from the combustion chambers which indicate the need for new piston rings, for this particular motor car engine.

2012

Kinney, Patrick L; Gichuru, MG; V-CN; NN; NPLA; GA;K; G.  2012.  Traffic Impacts on PM2.5 Air Quality in Nairobi, Kenya.

2010

Boman, Johan; Wagner, A; GMJ.  2010.  Trace elements in PM2.5 in Gothenburg, Sweden.

2009

Boman, J, GATARI MJ, Janhall S, Shannigrahi AS, Wagner A.  2009.  Elemental content of PM2.5 aerosol particles collected in G¨oteborg during the G¨ote-2005 campaign in February 2005. AbstractWebsite

The Gote–2005 measurement campaign aimed at studying the influence of the winter thermal inversions on urban air pollution. Elemental speciation of PM2.5 aerosol particles, collected on Teflon filters at three urban sites and one rural site in the Goteborg region, was a major part of the study. Trace element analysis was done by Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry and the concentrations of S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Br and Pb were determined. The elemental content of the particles, local wind speed and direction, and backward trajectories were used to investigate possible sources for the pollutants. We concluded that S, V, Ni, Br, and Pb had their main sources outside the central Goteborg area, since elevated concentrations of these elements were not observed during an inversion episode. Sea traffic and harbour activities were identified, primarily by the S and V content of the particles. This study showed that the elemental analysis by EDXRF presents valuable information for tracing the origin of air masses arriving at a measurement site.

Boman, J, GATARI MJ, Gaita SM, Zhang X, Xue B, Wagner A.  2009.  Seasonal variation in trace elemental concentrations in PM2.5 particles in Nairobi, Kenya.

2008

Wagner, A, Boman J, Gatari MJ.  2008.  Elemental analysis of size-fractionated particulate matter sampled in Göteborg, Sweden. AbstractWebsite

The aim of the study was to investigate the mass distribution of trace elements in aerosol samples collected in the urban area of Göteborg, Sweden, with special focus on the impact of different air masses and anthropogenic activities. Three measurement campaigns were conducted during December 2006 and January 2007. A PIXE cascade impactor was used to collect particulate matter in 9 size fractions ranging from 16 to 0.06 µm aerodynamic diameter. Polished quartz carriers were chosen as collection substrates for the subsequent direct analysis by TXRF. To investigate the sources of the analyzed air masses, backward trajectories were calculated. Our results showed that diurnal sampling was sufficient to investigate the mass distribution for Br, Ca, Cl, Cu, Fe, K, Sr and Zn, whereas a 5-day sampling period resulted in additional information on mass distribution for Cr and S. Unimodal mass distributions were found in the study area for the elements Ca, Cl, Fe and Zn, whereas the distributions for Br, Cu, Cr, K, Ni and S were bimodal, indicating high temperature processes as source of the submicron particle components. The measurement period including the New Year firework activities showed both an extensive increase in concentrations as well as a shift to the submicron range for K and Sr, elements that are typically found in fireworks. Further research is required to validate the quantification of trace elements directly collected on sample carriers.

G., DRGATARIMICHAELJ.  2008.  Gatari M. J., Pettersson J. B. C., Kimani W., Boman J., (2008). Inorganic and black carbon aerosol concentrations at a high altitude on Mt Kenya.. X-Ray Spectrometry; DOI 10.1002/xrs.1094.. : University of Nairobi.
G., DRGATARIMICHAELJ.  2008.  Gatari M.J., Boman J., Wagner A., (2008). Characterization of aerosol particles at an industrial background site in Nairobi, Kenya.. X-Ray Spectrometry; DOI 10.1002/xrs. 1097. : University of Nairobi. Abstract
Air pollutants from industrial sources contain harmful elements and chemical compounds. This work presents a study on background industrial and urban aerosol particles in the city of Nairobi. Its main focus was the understanding of elemental, black carbon (BC) and particulate mass (PM) concentrations in the perspective of identifying their sources. Aerosol particles were collected on Teflon filters in two size fractions, a fine fraction of particles having an aerodynamic diameter (da) < 2.5 m and a coarse fraction with particles between 2.5 m and 10 m. A photometer and an Energy Dispersive X-Ray Fluorescence spectrometer were used to analyze BC and trace elements (Si, S, Cl, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Pb), respectively. The sampled mass of the particulate matter was determined gravimetrically. The measured concentrations of the analysable species were dominated by BC, K, and S in the fine fraction and Si, Ca, and Fe in the coarse fraction. Principal component analysis and correlation evaluation of the fine fraction concentrations implicated industrial, vehicular, and biomass burning emissions as the main sources of the measured elements. The average Pb concentration of 105 ng m-3 in the PM10 sample at the background industrial site is approximately 20% of the Air Quality Guideline (AQG) recommended by World Health Organisation (WHO). Most of the measured elements exhibited higher concentrations than those measured in Francistown in Botswana, Dar es Salaam in Tanzania and Edinburgh in United Kingdom but less than those measured in Barcelona in Spain and from previous studies in Nairobi.
G., DRGATARIMICHAELJ.  2008.  Boman J., Gatari M. J., Janh. Atmos. Chem. Phys. Discuss; 8, 7703-7724.. : University of Nairobi.
G., DRGATARIMICHAELJ.  2008.  Gatari M.J.G., Strengthening National Facilities for the Maintenance and Repair of Medical and Scientific Instruments.. Oral presentation, First Project coordination meeting, AFRA IV, RAF/4/021. Arusha, Tanzania, 3-7 March 2008: Oral presentation, Workshop for Project Coordinators of National and AFRA/IAEA funded projects, Nairobi, Kenya, 4-5 August 2008. : University of Nairobi. Abstract
The project is hosted at the Institute of Nuclear Science & Technology (INST), University of Nairobi. One of the core mandates of the Institute is provision of scientific instrumentation maintenance and repair services to Educational and Research Institutions besides income generation through the wide scope of services. Nuclear instrumentation is part of the scientific instruments; consequently, the project enjoys the professional services of a strong technical team. INST is strongly founded on peaceful utilization of nuclear techniques in research and teaching and its management interest in this project is well demonstrated by the achievements, that is documented in this report. This report describes the achievement and impact of the just ended project, AFRA IV RAF/4/017 over the period 2002 to 2007. It also includes the available human resources to drive the new project, beneficiary institutions, expected needs and support as well as priorities. A brief on SWOT is included that highlights those that are perceived unique for Kenya otherwise most of it is the same as described in the last evaluation meeting of RAF/4/017 in Libya.
G., DRGATARIMICHAELJ.  2008.  Wagner A., Boman J., Gatari M. J., (2007). The elemental analysis of size-fractionated particulate matter using TXRF.. Corrected and re-Submitted to Spectrochimica Acta Part B.. : University of Nairobi.
G., DRGATARIMICHAELJ.  2008.  Gatari M.J., Maina D.M., Bartilol S., Gaita S.M., Determination of trace metals in bottled Commercial Drinking water using TXRF in Nairobi, Kenya.. Poster presentation, European conference on X-Ray Spectrometry (XRS2008), Cavtat, Dubrovnik, Croatia, 16-20 June 2008. : University of Nairobi.
G., DRGATARIMICHAELJ.  2008.  Naziriwo B.B., Wandiga S.O., Gatari M.J.G., Madadi O.V., Ssebuwufu P.J., Determination of trace metal concentrations in waters of Nakivubo Channel and Lake Victoria using Energy Dispersive X-Ray Fluorescence Analysis.. Poster presentation, European conference on X-Ray Spectrometry (XRS2007), Cavtat, Dubrovnik, Croatia, 16-20 June 2008. : University of Nairobi. Abstract
In an effort to understand the pollution levels in waters of Nakivubo channel in Kampala, Uganda and Lake Victoria (Fig 1) concentrations of Mn, Fe, Co, Cu, Zn and Pb were determined using convectional EDXRF and TXRF analysis. Water samples were collected with a 1-litre Van Don sampler (code, 1077) and transferred into polyethylene containers that were stored in an ice cooled box. Five samples were obtained at each sampling site and were all stored at -21 0C until analysis. Filtration on cellulose filter gave a particulate deposit that was analyzed for trace metals on a convectional EDXRF spectrometer. Pre-concentration and evaporation at 50 0C were used for extraction of dissolved metal content that was analyzed on TXRF. Samples of the unfiltered water were treated with HNO3 and H202 in a process for extracting total trace metal content that was subsequently prepared and analyzed on TXRF. Spectra from the spectrometers were analyzed for the trace elements of interest and elemental quantification was achieved using Quantitative X-ray Analysis software from International Atomic Energy Agency. The results showed high concentrations of particulate Fe and Mn, and relatively low Zn upstream the Nakivubo Channel. These were lower in the Lake Victoria waters. At the shores of Lake Victoria the dissolved Fe and Zn were higher than in the channel. The concentrations of Fe, Mn and Zn in Lake Victoria were below the USEPA maximum contamination limits of 0.3, 0.05 and 5 mg/L respectively. However, Fe at the mouth of Nakivubo Channel was high and in general the quantified total elemental concentrations increased upstream along the channel. This meant increased water pollution input upstream and along the channel.
G., DRGATARIMICHAELJ.  2008.  Gatari M.J.G., Boman J., Design and Development of an Energy-Dispersive X-ray Spectrometer: A tool for Environmental Research in Kenya.. Oral Presentation, 1st National Conference and Exhibition for Dissemination of Research Results and Review of Innovations and Exhibition, Ministry of Higher Education, Science and Technology. Nairobi, Kenya, 28-30 April 2008: Poster presentation, European. : University of Nairobi. Abstract
Contribution of scientific research to local and international journals from Africa and indeed Kenya is weak in comparison to other regions. One of the main problems is the non-availability of reliable and affordable analytical instrumentation. Energy-Dispersive X-ray Fluorescence (EDXRF) analysis is a special analytical technique for trace elements in that it is economical and easy to use. Its analytical capacity has the advantage of having multi-elemental characteristics and satisfactory speed. Convectional EDXRF analysis is used in identifying toxic trace elements in the general environment, trace elements in airborne particles for source apportionment, investigation of micronutrients in different ecosystems and agriculture practices among other areas of scientific investigations. A new EDXRF Spectrometer has been built and installed at the Institute of Nuclear Science and Technology, College of Architecture and Engineering, University of Nairobi. It is a new research tool that has improved local analytical detection limits of heavy metals in environmental and air pollution samples. A Siemens type D x-ray tube-stand was modified to facilitate x-ray irradiation of a Mo-secondary target. The target is a glued disk that was cut from a 1 mm thick Mo plate of 99.99 % purity. The fluoresced secondary x-rays propagate through three Ag collimators giving a near monochromatic Mo characteristic x-rays for sample excitation. The disk holder was designed to be easily removable, from the Al-measuring head, thus allowing the flexibility of carrying out experiments using different secondary targets. Air samples on Teflon filters and water samples on Cellulose filters were analyzed. The results were better than those obtained in previous spectrometer setups. The detection limits of trace elements improved by a factor of 10. The spectrometer is an extra facility for direct analysis of trace elements in air and other environmental samples.

2007

G., DRGATARIMICHAELJ.  2007.  Gatari M.J., Gaita S.M., Hays M.D., Bond T. C., Boman J., Assessment of criteria pollutants and NO in a typical urban aerosol in Africa.. Oral presentation, The 5th Asian Aerosol Conference (AAC2007), Kaohsiung, Taiwan (ROC), 26-29 August 2007. : University of Nairobi. Abstract
Criteria pollutants have health implications that are not only of concern to the urban population but also to governments in formulating their policies. These pollutants are also important to climate change investigations and any sustainable development programs require a properly informed population on their effects, concentration levels and sources. However, without the knowledge of the characteristic aerosol and information on the levels of pollutant concentrations, implementation of controls and enforcement of regulation remains difficult. NO and five species in the group of the criteria pollutants CO, NO2, SO2, PM2.5 and PM10 were measured at an urban background site in Nairobi, Kenya. The site is approximately 20 m above the ground, on top of a building at the main campus, University of Nairobi. Eight hour measurements at intervals of 10 s were obtained using pollutant gas monitors and 24 h samples of PM2.5 and PM10 particles were collected on glass fiber filters by a size segregating impactor. Figure 1 and 2 shows preliminary typical hourly average concentrations trends on a day in a weekend. The results imply a different daytime chemistry of NOX (= NO + NO2) from that reported in the literature. Typical measurements in urban boundary layer shows peaking of NO in early morning hours followed by NO2 and O3 in the afternoon. O3 oxidizes NO in a fast reaction to NO2 and O2. The recorded trend showed high rate of NO concentration replenishment, throughout the measurement period, in competition to its conversion to NO2. Similar trends of NO and NO2 were observed from about 1200 h until the end of the 8 h daytime measurement. This implied a near constant rate of NO oxidation that may have been the indicator of O3 production after 1130 at a concentration which was not capable of decreasing NO substantially. Normally, in urban aerosol, CO concentration is far much higher than the other gaseous pollutants but it was comparable to NO from midday. There was daytime SO2 which persisted at constant concentration of 0.1 ppm, the instrument indicator resolution value. High levels of CO were recorded in the early hours of the night and NO2 that persisted at 0.1 ppm. Considering that NO was high during the mid afternoon the nighttime NO2 concentrations portrayed a nighttime chemistry that converted NO to NO2. This conversion may have been driven by the peroxy radicals that are produced by reactions between NO3 radicals and reactive organic gases in the absence of sunlight. Since NO3 is a product of NO and O3 it followed that concentrations of the latter continued into nighttime.
G., DRGATARIMICHAELJ.  2007.  Gatari M.J., Hays D.M., Lavrich R.J., Gaita S.M., Determination of particulate carbonaceous species in an urban background aerosol in Nairobi, Kenya.. Poster presentation, The 5th Asian Aerosol Conference (AAC2007). Kaohsiung, Taiwan (ROC), 26-29 August 2007: Poster presentation, European Aerosol Conference (EAC2007), Salzburg, Austria, 9-14 September 2007. : University of Nairobi.

2006

G., DRGATARIMICHAELJ.  2006.  Gatari M.J., Boman J., Wagner A., Janhall S., Isakson J., (2006). Assessment of inorganic content of PM2.5 particles sampled in a rural area north-east of Hanoi, Vietnam. Sc. of Total Environ. 368: 675-685. Sc. of Total Environ. 368: 675-685. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
G., DRGATARIMICHAELJ.  2006.  Gatari M.J., Atmospheric aerosol studies in Kenya. Contribution by the Institute of Nuclear Science and Technology, University of Nairobi, Kenya.. Oral presentation, invited presentation, Copenhagen Centre for Atmospheric Research, University of Copenhagen, Denmark. 15th March 2006. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2006.  Impact of road transport on air quality in Kenya; Roadside survey in the cities of Mombasa and Nairobi. Poster presentation, abstract in the proceedings of the, International Aerosol Conference, St Paul Minnesota, USA,10 -15 September 2006: Poster presentation, Joint CACP-IGAC-WMO Conference, Cape Town, South Afric, 17 -23 September 2006. : University of Nairobi. Abstract
Criteria pollutants have health implications that are not only of concern to the urban population but also to governments in formulating their policies. These pollutants are also important to climate change investigations and any sustainable development programs require a properly informed population on their effects, concentration levels and sources. However, without the knowledge of the characteristic aerosol and information on the levels of pollutant concentrations, implementation of controls and enforcement of regulation remains difficult. NO and five species in the group of the criteria pollutants CO, NO2, SO2, PM2.5 and PM10 were measured at an urban background site in Nairobi, Kenya. The site is approximately 20 m above the ground, on top of a building at the main campus, University of Nairobi. Eight hour measurements at intervals of 10 s were obtained using pollutant gas monitors and 24 h samples of PM2.5 and PM10 particles were collected on glass fiber filters by a size segregating impactor. Figure 1 and 2 shows preliminary typical hourly average concentrations trends on a day in a weekend. The results imply a different daytime chemistry of NOX (= NO + NO2) from that reported in the literature. Typical measurements in urban boundary layer shows peaking of NO in early morning hours followed by NO2 and O3 in the afternoon. O3 oxidizes NO in a fast reaction to NO2 and O2. The recorded trend showed high rate of NO concentration replenishment, throughout the measurement period, in competition to its conversion to NO2. Similar trends of NO and NO2 were observed from about 1200 h until the end of the 8 h daytime measurement. This implied a near constant rate of NO oxidation that may have been the indicator of O3 production after 1130 at a concentration which was not capable of decreasing NO substantially. Normally, in urban aerosol, CO concentration is far much higher than the other gaseous pollutants but it was comparable to NO from midday. There was daytime SO2 which persisted at constant concentration of 0.1 ppm, the instrument indicator resolution value. High levels of CO were recorded in the early hours of the night and NO2 that persisted at 0.1 ppm. Considering that NO was high during the mid afternoon the nighttime NO2 concentrations portrayed a nighttime chemistry that converted NO to NO2. This conversion may have been driven by the peroxy radicals that are produced by reactions between NO3 radicals and reactive organic gases in the absence of sunlight. Since NO3 is a product of NO and O3 it followed that concentrations of the latter continued into nighttime.
G., DRGATARIMICHAELJ.  2006.  Michael James Gatari, (2006). PhD Thesis:- Studies of atmospheric aerosols and development of an EDXRF spectrometer in Kenya, Gotenburg University, Gotenburg, Sweden, ISBN 91-628-6755-5.. Publicly Defended , PhD Thesis: ISBN 91-628-6755-5.. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.

2005

M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2005.  Gatari M.J., Boman J., Maina D.M., "Trace Element categorization of pollution sources in the Equator town of Nanyuki, Kenya". X-ray Spectometry, 34:118-123. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
G., DRGATARIMICHAELJ.  2005.  Boman J., Gatari M.J., wagner A., Hossain M.I., (2005). Elemental characterization of aerosols in urban and rural locations in Bangladesh.. X-ray Spetrometry; DOI: 10, 1002/xrs.864, 460-467.. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
G., DRGATARIMICHAELJ.  2005.  Gatari M.J., Air pollution over East Africa.. Oral presentation, First International Workshop on Climate Variability over Africa. Alexandria, Egypt, 15-26 May 2005. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2005.  Gatari M.J., Kimani W., Boman J., Maina D.M., Pettersson J., Zakey A.S., Oral presentation "Study of inorganic and black carbon aerosols at a high altitude site on Mount Kenya, East Africa".. Oral presentation, The 6th informal conference on atmospheric and molecular science at Helsingor, Denmark, 3 - 5 June 2005. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2005.  Gatari M.J.,Boman J., Maina D.M., Pettersson J.B.C, Space Measurements of near surface aerosols in the central district of Nairobi City, Kenya. Poster presentation, abstrct in the preceedings, European Aerosol Conference (EAC2000), Ghent, Belgium, 28 August . : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.

2004

G., DRGATARIMICHAELJ.  2004.  Gatari M., Wagner A., Boman J., Elemental composition of tropospheric aerosols in Hanoi, Vietnam and Nairobi, Kenya.. Sc. of Total Environ, 341: 241-249. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2004.  Gatari M.J., Maina D.M., Air pollution problems in the perspective of the Kenyan situation, regulation and awareness.. Oral Presentation, International workshop on Environmental Health education in the Eastern African region: challenges and the way forward at Kenyatta University, Nairobi, Kenya. 24 - 26 March 2004. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2004.  Gatari M.J., Kimani W., Boman J., Maina D.M., Pettersson J., Zakey A.S., "study of trace metals in PM10 at Global Atmosphere Watch (GAW) station on Mount Kenya, Kenya, east Africa". European Aerosol Conference at Budapest, Hungary, 6 - 10 September 2004.. Poster presentation, European Aerosol Conference (EAC2004), Budapest, Hungary, 6 . : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2004.  Gatari M.J., Boman J., Maina D.M., Pettersson J.B.C., Application of Cd109 Source in evaluation of background industrial aerosols in Nairobi, Kenya, East Africa. - 2004. Poster presentation, European Conference on X-ray Spectrometry (XRS2004), Alghero, Italy, 6 - 11 June 2004. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.

2003

G., DRGATARIMICHAELJ.  2003.  Gatari M.J., Boman J. (2003). Black Carbon and total carbon measurements at urban and rural sites in Kenya, East Africa.. Atmospheric environ., 37: 1149-1154. : University of Nairobi. Abstract
There have been very few studies in Kenya on aerosols despite the global demand on aerosol ground studies in the perspective of climate and the human well being. Therefore, atmospheric aerosol studies became the basis of the work covered in this thesis which describes aerosol studies in Kenya and development of an energy dispersive X-ray fluorescence spectrometer (EDXRF). Atmospheric aerosols are composed of both the particulate and gas phases and they contain chemical compounds and elememts that are harmful to human health. Their particle size range is related to sources and this determines their impact in the ambient aatmosphere. Anthropogenic activities mainly contribute fine particles mass (PM 2.5) and natural proceses contribute both fine and course (PM (10-2.5)) particle masses. PM10 (PM 2.5 + PM (10-2.5)) are inhalable into the human respiratory system and the fine particles have a marked impact on climate. PM10 particles are efficient in transporting micronutrients between ecosystems, soiling and destroying buildings. Any policies meant to protect the environment by controlling atmospheric aerosol particles will need back up knowledge on particle sources and their physical and chemical characteristics. The five sampling campaigns covered under this study were conducted in Nairobi city, Meru and Nanyuki towns and on the slopes of Mount Kenya at about 2000m and 4000 m above the sea level. The multi-elemental analyzing capacity of EDXRF and statistical treatment of data are indispensable tools in aerosol source identification. These techniques were used in all the published results. The results revealed the dominance of local and regional biomass burning and local soil dust emissions. Traffic emissions were more pronounced in urban centers, with high concentrations of Br, Pb and Mn in Nairobi but with minor contribution at the remote sites on Mount Kenya. Marine influence was seen superimposed in the soil dust emissions and agricultural activities were also identied through elevated concentrations of Ca, Cl, K and S in the same source. Nairobi turned out to be a more polluted city in comparison to Dar es Salaam, Gaborone and Khartoum in Africa. The developed EDXRF spectrometer will play a major role in environmental studies in Kenya. Longterm measurements of Kenyan aerosols are recommended to better understand the total picture of aerosol particles including seasonal variation.

2002

G., DRGATARIMICHAELJ.  2002.  Gatari M.J., (2002). Studies of Atmospheric Aerosols at selected sites in Kenya.. Publicly Defended, Licentiate Thesis, Department of Physics and Engineering Physics, G. : University of Nairobi.
M., MRMAINADAVID, G. DRGATARIMICHAELJ.  2002.  Gatari M.J., Boman J., Maina D.M., Trace Element Categorization of Pollution Sources in the Equator Town of Nanyuki, Kenya.. Oral Presentation, abstract in the proceedings of the, European Conference on Energy Dispersive X-ray Spectrometry(XRS2002), Berlin, Germany: 16 - 21 June 2002. : University of Nairobi.

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