University of Dar es Salaam
The study says that urban outdoor air pollution is considered to be responsible for an estimated 63,000 premature deaths each year in Africa, which the study says implies that there is need for Tanzania to take immediate action and have proper data on the type, rate and source of air pollution.
Air pollution by pollutants such as industries, power plants, cars, buses, trucks, boats, windblown dust and open burning is growing rapidly in Tanzania, it has been learnt.
Emissions with direct and indirect effects with a wide range of impacts on human health, ecosystems, agriculture and materials are growing steadily, according to a study at the University of Dar es Salaam titled National Inventory of Air Pollution in Tanzania supervised by Professor Jamidu Katima of the Department of Chemical and Mining Engineering at the College of Engineering and Technology (CoET).
Emissions of oxides of nitrogen (NOX) were mainly caused by fire savannah burning and crop residue burning. Savannah burning during the dry seasons is a common agricultural practice in Tanzania and is normally used to eliminate weeds and pests, and to encourage growth of new grass for animal grazing through the promotion of nutrient cycling.
Other burning occurs accidentally due to excessive dryness of savannah vegetations. This periodic burning of a great portion of savannah areas releases large amounts of NOX emissions.
The report reads in part that significant amounts of CO emissions come from residential burning of wood fuels (2861.55 Gg), savannah burning (2,393.71 Gg) and vegetation fires and forestry (1,135.68 Gg). The three contribute 89 per cent of total CO emissions.
Due to unavailability of local activity data for savannah burning, the default data provided for the year 2000 of annual area burnt under savannah burning was adopted.
The study also revealed that animal husbandry, which is captured under ‘other agriculture,’ is the main emitter of ammonia in Tanzania and accounts for about 91 per cent of annual ammonia emissions under manure management systems.
It is a common by-product of animal waste (manure) due to the often inefficient conversion of feed nitrogen into animal product. The microbial decomposition of these wastes is the main source of ammonia from animal feeding operations, the report showse.
Other key sources are residential and waste management, which include pit latrines. High amounts of pollutant material are emitted from savannah burning, 352.02 Gg, followed by vegetation fires and forests 114.66 Gg,
The study also show that combustion in energy industry and residential contribute significant amount of pollutant material. The former may be attributed to the use of wood fuel and charcoal stoves, which have particularly high emissions of soot and fly ash.
Savannah burning contributes 44.3 percent of the total pollutant material of that type, followed by vegetation fires and forestry 23.2 per cent. Other combustion in energy industries contributes 21percent.
Emission estimates from all sectors in Tanzania show that there is an increasing trend of air pollution emissions compared to those reported in the Initial National Communication (2003).
This is because emissions are a function of population and social economic activities, the report says, noting that since population and social economic activities were on the rise, it is expected that emissions will be increasing year after year.
Since pollution exerts health impacts there is need to put in place policies geared to mitigating this increasing trend.
However, this is not possible until accurate estimates of pollutants can be established. “Such endeavour can only be possible if we improve our system of data collection, and data storage,” the study indicated.
This study has established that activity data is difficult to get as it has relied upon emission factors that were developed outside Tanzania and probably outside APINA member countries, a regional body for tracking emissions.
“We can only improve the accuracy of estimations if we can establish updated activity data and develop national emission factors,” it said, elaborating that activity data in Tanzania is poorly kept and data in almost all sectors is therefore unreliable. Sources of statistics are dispersed and such information lacks details and therefore the exercise of compiling inventory is difficult.
Update information of the disaggregated agriculture sector is not available as such estimation was based on estimated annual growth, it says, noting that estimation of waste generation was based on urban population and per capita waste generation of about 0.45kg.
A latrine is a simple dry toilet built outside the house over a hole dug in the ground or concrete, where the study assumed an average 91.3 percent of the population having and using toilet facilities, relying on 2001 to 2005 data.
At presently, urban air pollution in Sub Saharan African cities, including Dar es Salaam, appears to have gone up with respect to key pollutants due to rapid urbanisation, increased motorisation and other economic activities, including massive construction projects.
The situation in Dar es Salaam city is reported to be critical yet Tanzania is reliant on foreign countries for data on pollution rates and best practice solutions, the researchers noted. Since other cities have already gone through the process, Tanzania is advised to learn from them and adopt the best models for response, it says, citing the relevant countries as Colombia, South Africa, Brazil, China and Singapore, among others.
“To develop long term strategy and short term action plans for protection of human health, improved air quality and road safety, Tanzania and other countries in Sub-Saharan Africa must take accurate air pollution data particularly on transport related pollutants like trucks, motorcycles and commuter vehicles,” it said.
Dr Dieter Schwela from the Stockholm Environment Institute enumerated some of the issues at a stakeholders and research workshop on road safety, traffic flow management and air pollution organised by Ardhi University, with support from the Transport and Environment-Science Technology (TEST) network led by the Stockholm Environment Institute at the University of York in Britain.
As result, there is need for Tanzania to conduct research and collect proper data on air pollution and this data should go to a data based management system computerized to develop best response strategies based on generated simulation displaying the magnitude of the problem currently and in the future.
Data on air pollution will also help stakeholders in the transport policy makers to conceptualize the level of problems, allowing them to develop tactics to improve the quality of air as well as to improve road safety, including reducing road congestion.
“The country must call on researchers to help define priorities and set objectives for reducing emissions as well as assessing the potential impacts of different reduction strategies on current levels of emission and forecast future emission levels to determine which emission source might require further control,” the study implored.
There is also need for Tanzania to train more people on Air Quality Monitoring and Air quality standards if it is to have qualified experts providing proper data on sir pollution that will help Tanzania protect the population and the environment, the report added.
SOURCE:
THE GUARDIAN
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