An article entitled “How higher temperatures and pollution are affecting mosquitoes” by Shüné Oliver in 2019 talks about the effect of human activity (including water pollution and anthropogenic climate change) on mosquitoes. In this post, I’d like to highlight in particular the effect of water pollution on mosquito breeding. For context, Oliver and his team are from the National Institute for Communicable Diseases and they track malaria cases and mosquito behaviour in South Africa.
While mosquitoes usually breed in clean water, Oliver says that they have adapted such that they can now breed in polluted water. Consequently, mosquitoes carrying disease-causing viruses and pathogens, like the malaria parasite, are able to spread to more areas where such diseases were uncommon.
Mosquitoes that have adapted to toxic water also develop resistance to various toxins. Oliver’s team found that mosquitoes exposed to metal as larvae are resistant to insecticide. This further expands the range at which mosquitoes are able to transmit diseases.
As we are well aware, mosquito-borne diseases like malaria, Zika and dengue are hugely problematic. For example, according to WHO, nearly half of the global population is at risk of malaria and there were an estimated 241 million cases of worldwide in 2020. I think it is likely that those in poverty, especially those in places where mosquito breeding has always been more prevalent, will suffer more from the consequences of these evolved mosquitoes. Oliver says most malaria deaths occur in Africa, especially in sub-Saharan Africa.
Though the aforementioned diseases are preventable and treatable, the discovered mosquito adaptations will make prevention increasingly difficult with the growing inability to control mosquito populations. When people’s lives are at stake, it is ethically desirable that we work on preventing the problem from occurring. Efforts should be made NOW, rather than waiting until there is an even worse crisis of disease outbreak, and addressing water pollution would be a good place to start.
References:
https://theconversation.com/how-higher-temperatures-and-pollution-are-affecting-mosquitoes-114768
