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.

Samples of coarse, fine and PM10 aerosols were collected at a rural

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.

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 (NO 3 −) 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 NO 3 − 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 NO 3 − 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.

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 PM 10 mass, as derived from the stacked filter unit samples, was, on average, 58 µg/m 3. 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 PM 10 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.