Reduced Visibility in Urban Africa Links to Increased Air Pollution

The reduction in visibility in three major African cities has shown the vast increase in air pollution over the last 5 decades. A recent study, from the University of Birmingham, has shown that there has been an increase in the man-made pollution from economic development and urbanisation.

Due to the lack of infrastructure Africa does not have much in the form of air quality monitoring. Therefore, the scientists have used data on the visibility of the air for the capital cities in Uganda, Kenya and Ethiopia as a measurement.

Since the 1970s the researchers found a large reduction in the visibility within the cities. Nairobi had the greatest loss of visibility of 60 per cent whilst Kampala and Addis Ababa had losses of 56 per cent and 34 per cent respectively. The large reduction in visibility is thought to be from increased particulate matter emissions which is produced from energy generation and vehicles.

The particulate matter pollution levels in each city have seen a significant increase of 182 per cent in Nairobi, 162 per cent in Kampala and 34 per cent in Addis Ababa since the 1970s to now.

The researchers from the University of Birmingham published what they found in Environmental Research Letters and are now calling for an approach to be led to try and understand the main cause and effects of high air pollution levels in the cities of East Africa. This will then allow for improvements in the air quality levels whilst promoting a sustainable and green future economic development for the nations.

Dr Ajit Singh, a co-author on the report stated that the evidence shows that the quality of air in African cities is more often than not poor which is due to the increased population growth and urbanisation which causes higher levels of construction, energy usage, vehicle emissions and industrialisation.

Dr Singh went on to comment on his concern on the levels of particulate matter in East Africa and the negative side effects that it has on human health. The lack of air quality monitoring means that there is little data available but the visibility in each city can be used as a proxy.

Dr William Avis, a co-author has stated that high air pollution levels are a major economic, health and social threats to any city around the world and thus East Africa is no exception. However, the lack of available reliable air quality data does make it harder to track the pollution levels.

The lead of A Systems Approach to Air Pollution and co-author on the report, professor Francis Pope commented that it is essential to find out the main causes and effects of high air pollutions levels for the African cities as they are very rapidly developing which will lead to further increases in their air pollution levels. Poor air quality has many knock-on effects for a nation as governments have to increase their spending on health, loss of productivity and the impact illness will have on education which slows the country’s development down.

The scientists also compared the changes in pollution levels to the GDP statistics and population growth rates. They found that the increased particulate matter was linked with an increase for the nations GDP and the populations for each of the three cities. Links were also found between the levels of particulate matter and the season, during the dry month’s visibility was lowest whilst being highest in the wet months. Visibility as also the highest on Sundays as there is less traffic and emissions from industry.

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