Man with his untiring efforts has made life more comfortable or sophisticated. He has dived deep into the seas, soared to the sky, landed on the Moon, tamed wild animals but failed to eradicate the ‘brown bird’ which hovers over our heads, sucks blood and causes many diseases like malaria, dengue fever, filariasis and the culex triteniorhyncus that causes encephalitis. This ‘virus’ is bred in the sewage and infects children who do not have resistance.
The scientific theory is that mosquitoes search for carbon dioxide exhaled from humans to select their prey and then attack. Another factor is the ‘pheromones’ which attract the mosquitoes. Hence this smell/odour is camouflaged using repellents. But mosquitoes still thrive and threaten humans.
For centuries the man has fought against mosquitoes but has not won and is still waging a war, this time with the most widely used weapons — coils, liquids and battery-operated ‘hunter bats’. Yet the mosquitoes in battalions bite humans, struggling at night for a few hours’ sleep.
The authorities blame it on the ways of the people although they miserably fail to prevent sewage water flow into open drains because of which the mosquitoes breed and multiply robustly. As a ritual, the municipal authorities resort to ‘fogging’ — using chemicals mixed pungent vapour, letting out as smoke in the hope of driving away the brown birds.
But it is we who are driven inside behind closed doors when ‘fogging’ takes place while mosquitoes run helter-skelter briefly taking shelter on the top of trees and roofs, return triumphantly the moment the ‘smoke’ dissipates. As usual the brown birds make forays and select their prey, with more vengeance, bite and suck blood, inject disease-causing fluids with their tiny, powerful trunks.
And their gained resistance or immunity is such that many a times one can find a mosquito resting on top of a burning coil.
In a few remote villages in Andhra Pradesh where agriculture is the main occupation, mosquitoes are not to be found. Why? One can find the women-folk preparing cow dung cakes on the walls and a few households have gobar gas plants in which dung mixed with water is used to produce ‘fuel’ for all cooking purposes. The methane (gas) which emanates from the dung kills the larva. The repellent coils we find in the market contain Pyrethrins, Allerthin and Piperonyl butoxide.
But burning a mosquito coil produces the same amount of particulate mass 75-137 burning cigarettes would, and the emission of formaldehyde from one burning coil can be as high as that released from 51 burning cigarettes.
Once I wanted to conduct an experiment with cow dung cake, allowed one piece in each room to burn for 15 minutes. The smoke proved to be more effective than branded ‘coils’ in keeping the mosquitoes away. Try this, curl on conveniently and sleep well.
Why not our repellent manufacturers produce coils based on cattle or elephant dung rather than using chemicals harmful to us?
In Bihar, elephant dung is used as a repellent, particularly in winter to fight against the mosquito menace. It is cheap and much sought after since its burnt smoke is considered as an instant killer of mosquitoes and it does not pollute.
timeout@expressbuzz.com