Elemental composition of atmospheric particulate matter during 2006 wet season at a rural background site in Tanzania

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 weighing. A further analysis was performed for 25 elements by particle-induced x-ray emission spectrometry. The results show  that the concentrations of the heavy metals were lower than those for the elements of crustal origin. The data from PIXE analysis and enrichment factor  (E.F.) calculation, using Fe as a reference of crustal material, showed that for the coarse size fraction, most elements have crustal EFs that are very close to one, while enriched elements (E.F. > 10) like S, Cl, Zn, As, Br, Pb and BC, predominated in fine (PM2) size fraction (an anthropogenic origin can be suggested for the later). Potassium a well-known indicator for biomass burning was mostly associated with the fine particles (as around 56% of the PM10 K was in the PM2 size fraction). This suggests that biomass burning was important in Morogoro. Five-day isentropic backward trajectories as determined by the air trajectory HYSPLIT model were computed for Morogoro and the allocated sector of oceanic origin over continental, mainly through Mozambique and Tanzania) was the most common. However, other sectors such as Oceanic, over Madagascar or continental origins were observed. @JASEMJ. Appl. Sci. Environ. Manage. December, 2010, Vol. 14 (4) 135 – 13

Assessment of Work Zone Noise Levels at a Cement Factory in Tanga, Tanzania

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 measured using a digital sound level meter at three appropriate locations of the working zone of the workers. Questionnaires were provided to each worker in selected production section and field under close supervision to avoid influence of one’s results by other subject. The results showed maximum noise level at the power plant section with 104.82 dBA and minimum noise level was 50 dBA observed in offices. The maximum and average noise levels measured in most production sections exceeded the allowed limit value of 85 dBA as recommended by Tanzania Bureau of Standards (TBS). Subjective responses indicated that 47.5% of workers are exposure to noise for more than 5 years whereas, 82.5% of workers indicated that there could be health effects caused by the noise from machines. The study suggests that, though most workers ever use protective gears during working hours, health checkups for noise related effects should be carried out regularly.Keywords: Noise levels, Noise exposure, Cement factory, Survey, Tanzani

Attitudes of Community to Urban Traffic Noise in Morogoro, Tanzania

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 meters was used for measurement of noise level. The average noise equivalent level at measured points varied between 51.1 to 75.1 dBA. The results established the fact that noise levels are more than the acceptable limit of 55 dBA, which is the daytime governmentally prescribed noise limit for residential-commercial areas. This study also describes the reaction of the Morogoro residents to environmental noise pollution. A total of 200 questionnaires were processed. The results of the interview questionnaire revealed that the main isolated noise source was traffic (51%) and street noise (29%). About 45% of the respondents classified the noise in their street as “high”; and that noise bother 77% of the respondent more in daytime. The main impacts of exposure to noise were reported to be headache, hearing problem, sleeplessness, difficulty to concentrate and conversation disruption. This study recommends raising community awareness on noise pollution, structural management, traffic management and enforcement of laws and regulations so as to control noise pollution. Keywords: Noise pollution, Vehicles, Annoyance, Urban public, Diurnal variatio

Elemental Composition and Sources of Atmospheric Particulate Matter in Dar es Salaam, Tanzania

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 made. All samples were analysed for the PM mass by weighing. A further analysis was performed for 25 elements by particle-induced x-ray emission spectrometry. The PM10 mass, as derived from the stacked filter unit samples, was, on average, 58 μg/m3. The concentrations of the heavy metals were lower than those for the elements of crustal origin. Nevertheless, some typical anthropogenic metals, such as Zn and Pb, exhibited much higher median PM10 levels, suggesting strong local sources for these elements in Dar es Salaam. The results also showed very strong day/night differences for the crustal elements (Al, Si, Ca, Ti and Fe). Most elements exhibit strong correlations in the coarse size fraction and somewhat weaker ones in the fine size fraction suggesting that they may originate predominantly from the same source. Principal component analysis with VARIMAX rotation was applied to the data set. Five and four components were identified for the fine and coarse fractions and explained 86.5% and 90.8% of the variance in the data set respectively.Keywords: PIXE; Atmospheric Aerosols; Elements; Size Fractions; PCA; Kerbsid

Estimation of local and external contributions of biomass burning to PM2.5 in an industrial zone included in a large urban settlement

A total of 85 PM2.5 samples were collected at a site located in a large industrial zone (Porto Marghera, Venice, Italy) during a 1-year-long sampling campaign. Samples were analyzed to determine water-soluble inorganic ions, elemental and organic carbon, and levoglucosan, and results were processed to investigate the seasonal patterns, the relationship between the analyzed species, and the most probable sources by using a set of tools, including (i) conditional probability function (CPF), (ii) conditional bivariate probability function (CBPF), (iii) concentration weighted trajectory (CWT), and (iv) potential source contribution function (PSCF) analyses. Furthermore, the importance of biomass combustions to PM2.5 was also estimated. Average PM2.5 concentrations ranged between 54 and 16 μg m−3 in the cold and warm period, respectively. The mean value of total ions was 11 μg m−3 (range 1–46 μg m−3): The most abundant ion was nitrate with a share of 44 % followed by sulfate (29 %), ammonium (14 %), potassium (4 %), and chloride (4 %). Levoglucosan accounted for 1.2 % of the PM2.5 mass, and its concentration ranged from few ng m−3 in warm periods to 2.66 μg m−3 during winter. Average concentrations of levoglucosan during the cold period were higher than those found in other European urban sites. This result may indicate a great influence of biomass combustions on particulate matter pollution. Elemental and organic carbon (EC, OC) showed similar behavior, with the highest contributions during cold periods and lower during summer. The ratios between biomass burning indicators (K+, Cl−, NO3−, SO42−, levoglucosan, EC, and OC) were used as proxy for the biomass burning estimation, and the contribution to the OC and PM2.5 was also calculated by using the levoglucosan (LG)/OC and LG/PM2.5 ratios and was estimated to be 29 and 18 %, respectively

Nitrate pollution of Neogene alluvium aquifer in Morogoro municipality, Tanzania

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 (NO3 -) 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 NO3 - 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 NO3 - 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 tends 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

Cooking fuels and respiratory symptoms in kitchen workers in Morogoro Municipality, Tanzania

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 and consisted of 234 females and 126 males. The kitchen workers from 104 selected kitchens in hotels, fast food restaurants, institution, food vendors and in households of the general population were interviewed using a questionnaire. Information on the presence of dry cough, productive cough, running nose, irritation of nose or eyes, and chest pain in connection with work were asked. The overall respiratory symptoms were observed in 68.9% of the surveyed kitchen workers. With the exception of dry cough, females encountered 61.54% of productive cough, 57.69% running nose, and 71.28% irritation of nose or eyes. Chest pain and irritation of nose and eyes were more common in kitchen workers that use biomass fuel, charcoal and/or kerosene than other cooking fuels. The results of the study indicate a significant relationship (p < 0.05) between use of different cooking fuels and respiratory symptoms. However, further studies are needed to support the present results.© 2010 International Formulae Group. All rights reserved.Keywords: Kitchen work; cooking fuels; Respiratory infection; Cook

Significance of terrestrial inflows to carbon and nitrogen distribution in the Lake Victoria surface water

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 ratio values decreasing towards the deeper lake water, an indication of decreasing nitrogen content relative to carbonic materials. Samples away from the river mouth provided C:N ratios within the Redfield ratio range (C:N:P; 106:16:1) indicating materials of phytoplanktonic origin. The POM isotopes composition indicated a maximum &auml;13C value of .21.2&permil; close to the river mouth and lowest value (~ .25&permil;) away from the river influence. The &auml;15N maximum (14.7&permil;) was observed near the river mouth with lower values (5.8&permil;) found in deeper waters away from the river mouth. Overall, there was a general decrease of 13C and &auml;15N values from shallow water to deeper water. There was higher &auml;15N value dispersion (std. Dev. &plusmn;3.4&permil;) compared to &auml;13C values with std. Dev.&plusmn;1.2&permil;. These values also varied with seasons, a phenomenon showing significant influence of land run off on the lake elemental distribution, carbon and nitrogen in particular