Stagnant waters created by dam reservoirs in sub-Saharan Africa generate perfect conditions for malaria-spreading Anopheles mosquitoes to breed and multiply, and a recent study shows that it is the 14.6 million people living within the 5km flight range of those mosquitoes who are increasingly suffering the consequences.
The research by the University of New England in Australia finds that an annual 1.1 million cases of malaria in high-risk areas across the region can be associated with people living in the vicinity of a dam. This figure is expected to rise by another 56,000 cases annually as new dams are built, with evidence suggesting that proximity to the structures makes the chances of contracting malaria 3.2 times higher than people living further away in the region.
‘While dams clearly bring many benefits – contributing to economic growth, poverty alleviation and food security – adverse malaria impacts need to be addressed or they will undermine the sustainability of Africa’s drive for development,’ says biologist Solomon Kibret, the study’s lead author.
Sub-Saharan Africa is currently home to 1,268 dams, with another 78 in the pipeline. With 723 of those already existing and 60 of the newly planned dams being located in malarious areas, developers are now being encouraged to take action to mitigate the spread of the disease. These include measures such as introducing fish into the reservoirs to eat the mosquito larva and providing extensive mosquito nets, as well as reconsidering the placement and design of future dams.
‘Dams are an important option for governments anxious to develop,’ says study co-author Matthew McCartney, from the International Water Management Institute. ‘But it is unethical that people living close to them pay the price of that development through increased suffering and, in extreme cases, loss of life due to disease.’
This article was published in the December 2015 edition of Geographical magazine.