Suspended particulate matter and its relations to the urban climate in Dar es Salaam, Tanzania

Jonsson, Per R.; Bennet, Cecilia; Eliasson, Ingegärd; Lindgren, Eva

doi:10.1016/j.atmosenv.2004.04.021

Cited by 66 publications

(35 citation statements)

References 5 publications

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“…Short-term differences of atmospheric metal concentration has been observed in a day-to-day or even hour-to-hour (Gharaibeh et al, 2010). The distribution of trace elements in airborne particulates shows significant variations with the meteorological conditions in different parts of the world (Jonsson et al, 2004;Shaheen et al, 2005). Metals associated with ambient aerosols catalyze oxidative stress (Muránszky et al, 2011), and may be responsible for production and release of inflammatory mediators by the respiratory tract epithelium, which contribute to the toxic effects of particulate air pollutants reported in epidemiological studies (Carter et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Seasonal Behaviours and Weekdays/Weekends Differences in Elemental Composition of Atmospheric Aerosols in Cairo, Egypt

Hassan

El–Abssawy

Abdelmaksoud

et al. 2013

Aerosol Air Qual. Res.

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The aim of the present study was to investigate the seasonal distributions and weekdays/weekends differences in ambient aerosols and their elemental contents in the atmosphere of the 15 May City, Egypt. Aerosol samples were collected from March 2009 to February 2010. The concentrations of 14 elements including Na, Mg, Ca, K, Al, Fe, Mn, Co, Cu, Zn, Ni, Cd, Pb and Cr were measured by Atomic Absorption Spectrophotometry (AAS). The mean aerosols concentrations were 290 µg/m 3 (spring), 250 µg/m 3 (summer), 330 µg/m 3 (autumn) and 400 µg/m 3 (winter). The measured elements showed a strong seasonal variation; with the highest concentrations in winter and the lowest in summer. Na, Mg, Ca, K, Al and Fe were the dominant elements, followed by Mn, Cu, Zn, Ni and Pb. The minimum concentrations were noted for Co, Cd and Cr. The dominant elements in aerosol represented 94%, 94.51%, 94.61% and 94.28% from the total measured elements and 5.08%, 5.74%, 6.11% and 5.44% from aerosol mass during winter, spring, summer and autumn, respectively. The aerosols concentrations on weekends were reduced by 31.25% in the winter and 15.2% in the summer. The concentrations of the measured elements were higher on weekdays than weekends. The weekday/weekend concentration ratios were 1.69 and 1.38 for total measured elements during winter and summer, respectively. The mean Ni and Cd levels were higher than the proposed WHO, USEPA and the European Community standards. Significant positive correlations were found between the concentrations of aerosols, Mg, Ca, K, Al, Fe, Mn, Co, Zn and Cr. The enrichment factors (EFs) and the non-crustal fractions of all elements indicated that Na, Mg, Ca, K, Fe and Mn originate mainly from soil sources, whereas Co, Cu, Zn, Ni, Cd, Pb and Cr are mostly emitted in the atmosphere of 15 May City from anthropogenic sources.

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Section: Introductionmentioning

confidence: 99%

Seasonal Behaviours and Weekdays/Weekends Differences in Elemental Composition of Atmospheric Aerosols in Cairo, Egypt

Hassan

El–Abssawy

Abdelmaksoud

et al. 2013

Aerosol Air Qual. Res.

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“…Less work is available from Africa (e.g. Dar es Salaam: Jonsson et al, 2004;Luanda: Ferreira-Baptista and De Miguel, 2005) and dry subtropical regions outside India (e.g. Phoenix: Doran et al, 2003;Lee et al, 2003).…”

Section: Air Quality and Pollutionmentioning

confidence: 99%

Review of urban climate research in (sub)tropical regions

Roth

2007

Intl Journal of Climatology

327

208

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Abstract:Over the last 50 years the developing world, much of which is located in (sub)tropical regions, has seen a dramatic growth of its urban population associated with serious degradation of environmental quality. The total number of (sub)tropical urban climate studies, however; is still small (<20% of all urban climate studies). The available work is further biased towards descriptive studies rather than process work that seeks to indicate the physical climatology of (sub)tropical cities. The available results allow for a preliminary comparison with data from temperate latitudes. Urban heat island (UHI) intensities are generally lower compared to those of temperate cities with comparable population and show a seasonal variation with lower (higher) intensities during the wet (dry) season. (Sub)tropical population-based relations may exist but insufficient appropriate data is available to confirm a logarithmic relationship or systematic differences between different climate types. The (sub)tropical energy balance studies are biased towards dry, clear sky conditions. The amount of net radiation dissipated by sensible heat during daytime is about 40% which is similar to values observed in (sub)urban areas of cities located in temperate climates. Energy partitioning is modulated by water availability and higher percentage of vegetation promotes latent heat flux at the expense of surface heat storage. The apparent strong influence of vegetation and water availability on the energy partitioning irrespective of the climate type, suggests vegetation to be an effective means to reduce heat storage uptake during daytime and hence has the potential to effectively mitigate the nocturnal heat island. It is important to ensure that the rapidly expanding cities of the developing world incorporate climatological concerns in their design to provide a better living and working environment for a large segment of the world's inhabitants. Copyright  2007 Royal Meteorological Society KEY WORDS tropical urban climatology; tropical urban heat island; tropical urban energy balance

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“…The wind speed may also affect the PM 10 concentration (Jonsson et al 2004) and GST (Agarwal and Tandon 2010) which consequently may affect GST b6 retrieval from images. In order to gain a better understanding of the atmospheric condition during the time when the images were taken, the relationship between wind speed with GST, PM 10 concentration and GST b6 retrieval from images were analyzed using nonlinear correlation coefficient (NLCC) ( Table 2).…”

Section: Resultsmentioning

confidence: 99%

Development of the models to estimate particulate matter from thermal infrared band of Landsat Enhanced Thematic Mapper

Amanollahi

Tzanis

Abdullah

et al. 2013

Int. J. Environ. Sci. Technol.

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Particulate matter concentration and assessment of its movement pattern is crucial in air pollution studies. However, no study has been conducted to determine the PM 10 concentration using atmospheric correction of thermal band by temperature of nearest dark pixels group (TNDPG) of this band. For that purpose, 16 Landsat Enhanced Thematic Mapper plus ETM? images for Sanandaj and Tehran in Iran were utilized to determine the amount of PM 10 concentration in the air. Thermal infrared (band 6) of all images was also used to determine the ground station temperature (GST b6) and temperature of nearest dark pixels group. Based on atmospheric correction of images using temperature retrieval from Landsat ETM?, three empirical models were established. Nonlinear correlation coefficient with polynomial equation was used to analyze the correlations between particulate matter concentration and the ground station temperature for the three models. Similar analyses were also undertaken for three stations in Klang Valley, Malaysia, using 11 Landsat ETM? images to show the effectiveness of the model in different region. The data analysis indicated a good correlation coefficient R = 0.89 and R = 0.91 between the trend of the result of temperature of nearest dark pixels group b6 -(GST b6 -GST) model and the trend of PM 10 concentration in Iran and Malaysia, respectively. This study reveals the applicability of the thermal band of Landsat TM and ETM? to determine the PM 10 concentration over large areas.

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Suspended particulate matter and its relations to the urban climate in Dar es Salaam, Tanzania

Cited by 66 publications

References 5 publications

Seasonal Behaviours and Weekdays/Weekends Differences in Elemental Composition of Atmospheric Aerosols in Cairo, Egypt

Seasonal Behaviours and Weekdays/Weekends Differences in Elemental Composition of Atmospheric Aerosols in Cairo, Egypt

Review of urban climate research in (sub)tropical regions

Development of the models to estimate particulate matter from thermal infrared band of Landsat Enhanced Thematic Mapper

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