Trace element categorization of pollution sources in the equator town of Nanyuki, Kenya

Gatari, Michael; Boman, Johan; Maina, D. M.

doi:10.1002/xrs.771

Cited by 9 publications

(13 citation statements)

References 15 publications

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“…[34] The concentrations were approximately 5-50 times higher for all elements at the two urban sites compared to the remote site on Mt Kenya. In Nanyuki [14] a similar fine/coarse ratio was obtained in the four sites of that study except for the S and Pb ratios which were more than twice the Nanyuki ratio in this study. In Nairobi [34] differences were noted for Ni, Rb and PM.…”

Section: Meteorology and Atmospheric Circulationsupporting

confidence: 86%

“…[27 -29] CMB is a model that calculates the contributions of known sources to the aerosol that is measured at a receptor site using the known chemical constituent profiles and strengths of the source. Critical scrutiny of the observed elemental concentrations during the campaign together with knowledge from other measurements in Kenya [9,10,14] indicated that soil dust, biomass burning, vehicle emissions, sea salt and sulfate could be the dominant components that were likely to make major contributions to the aerosol mass at Mt Kenya. Organic compounds and some inorganic components like nitrates were also likely to significantly contribute to the aerosol, but our chemical analysis did not include these components and they were left out of the CMB.…”

Section: Receptor Modelingmentioning

confidence: 99%

“…The geometry is optimized for analysis of aerosol filters, with a distance of 2.7 cm between the sample and the detector. [14] The x-ray tube was operated at 55 kV and 25 mA and a lifetime of 500 s was used for spectrum collection. A standard reference material consisting of aerosol particles on filter media SRM2783 [National Institute of Standards and Technology (NIST), Gaithersburg, USA] was used to calibrate the spectrometer, while SRM1833 (Thin Glass Film on Polycarbonate for x-ray Fluorescence Spectrometry, National Bureau of Standards, now NIST, Gaithersburg, USA) monitored reproducibility of the spectrometer at selected times during analysis.…”

Section: Instrumental Description and Sample Analysismentioning

confidence: 99%

“…7, the mean elemental concentrations measured at Mt Kenya are compared with two sets of urban background measurements in Kenya. One of the measurements [14] was performed in the small town of Nanyuki, about 40 km west of the current measurement site on Mt Kenya, and the other at an industrial background site in Nairobi city. [34] The concentrations were approximately 5-50 times higher for all elements at the two urban sites compared to the remote site on Mt Kenya.…”

Section: Meteorology and Atmospheric Circulationmentioning

confidence: 99%

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Inorganic and black carbon aerosol concentrations at a high altitude on Mt Kenya

2008

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Section: Meteorology and Atmospheric Circulationsupporting

confidence: 86%

Section: Receptor Modelingmentioning

confidence: 99%

Section: Instrumental Description and Sample Analysismentioning

confidence: 99%

Section: Meteorology and Atmospheric Circulationmentioning

confidence: 99%

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Inorganic and black carbon aerosol concentrations at a high altitude on Mt Kenya

2008

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“…These advantages make it a valuable tool for analysis of environmental samples like aerosol particles. [12] The EDXRF spectrometer used in this study is located at the department of physics, University of Lisbon, Lisbon, Portugal. This spectrometer uses a W x-ray tube as an excitation source, and a secondary target of Mo.…”

Section: Methodsmentioning

confidence: 99%

Elemental content of aerosol particles in an underground tram station

et al. 2009

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Particulate matter is an important air pollutant, especially in closed environments like a tunnel. The aim of this study was to determine the mass, black carbon, and elemental concentrations of particulate matter of two size fractions at an underground tram station in Hammarkullen, Gothenburg, Sweden. Samples were collected during June 2007 using a dichotomous virtual impactor separating the sampled aerosol particles into coarse (PM (2.5 -10) ) and fine (PM 2.5 ) fractions. To minimize the possible influence of waiting passengers, the platform for trams going towards the suburb Angered was chosen. The elemental analysis of the samples, collected on Teflon filters, was carried out using energy dispersive x-ray fluorescence (EDXRF) spectrometry, resulting in concentrations of 14 elements in most of the samples. Principal component analysis (PCA) was applied to identify possible sources for the elements in the particles. Owing to the tunnel environment, the elemental difference between the fine and coarse particle fractions was not as large as that in similar particles collected under normal outdoor ambient conditions. Likewise, the influence of the local weather situation was not significant. Particle content from the tram traffic was identified by PCA, with Fe being the major element in both coarse and fine particles. The particle mass concentration was higher in the tunnel compared to the ambient concentration at the monitoring station Femman in downtown Gothenburg. In some days, the mass concentration exceeded the Swedish daily ambient air quality standard of 50 µg m −3 , but it was lower than the limits in the environmental work act, 5 mg m −3 .

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Characterization of aerosol particles at an industrial background site in Nairobi, Kenya

2008

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Air pollutants from industrial and urban 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 (d a ) <2.5 µm and a coarse fraction with particles between 2.5 and 10 µm. A photometer and an energy dispersive x-ray fluorescence spectrometer were used to analyse 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 PM 10 samples at the background industrial site was 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.

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Trace element categorization of pollution sources in the equator town of Nanyuki, Kenya

Cited by 9 publications

References 15 publications

Inorganic and black carbon aerosol concentrations at a high altitude on Mt Kenya

Inorganic and black carbon aerosol concentrations at a high altitude on Mt Kenya

Elemental content of aerosol particles in an underground tram station

Characterization of aerosol particles at an industrial background site in Nairobi, Kenya

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