Mosquitoes circulating in parts of Nairobi are highly contaminated with toxins, dangerous to humans including mercury and lead.
Researchers have already established the contamination and are investigating whether the insects can transmit the same to humans.
The team suggests such a possibility and warns that the mosquitoes may be transmitting both diseases as well as toxic pollutants to humans.
“The possibility of urban mosquitoes transferring the heavy metals to the urban population should be investigated further,” the researchers say.
The team from the Kenya Medical Research Institute (KEMRI), Laikipia University and Daystar University both of Kenya, had sampled mosquitoes breeding in wastewaters in Nairobi industrial area and neighbouring estates.
Affected residential areas include Donholm Estate, Mukuru and Viwandani slums and many more as the wastewater runs into Nairobi River which joins Athi River further downstream.
Samples of wastewater, algae and adult and mosquito larvae were collected from the study area and analyzed at KEMRI laboratories.
These were found contaminated with mercury, lead, chromium, cadmium, thallium, and nickel at significant levels.
The mosquitoes were contaminated with high levels of lead, chromium, thallium, and nickel and mercury to a lesser level.
Lead, cadmium, mercury and thallium are some of the most poisonous heavy metals to humans. They are associated with a wide range of harmful effects on humans and animals.
Such may include cancers, systems disorders, birth defects, cellular and DNA damage and neurological disorders.
The study published on Monday (11th October 2021) in the journal BMC Ecology and Evolution suggests further studies and better treatment of industrial wastewaters.
“Strict environmental and public health policies should be formulated, adopted, and made to work to manage industrial effluents effectively.”
By Gatonye Gathura