Mosquito repellents demystified
By Roshni Sengupta


Remember that peculiar advertisement that features a man leaping about like a frog, clucking his tongue at buzzing mosquitoes? It made the mosquito repellent vaporizer the most favoured way of getting rid of troublesome mosquitoes. The good old repellent coil went completely out of fashion, altering the manner in which households protected themselves against pests and insects. 

Vaporizer sales soared and so did the manufacturers’ incomes. The impact of chemical vaporizers on human health has been a cause for concern for a while now, with long-time users complaining of nervous disorders. Currently, a variety of repellents are marketed in the form of mats, coils, lotions, and vaporizers. These repellents use the allethrin group of compounds, herbs, oils, or DEET (diethyl toluimide). 

Research shows that the main site of action of the pyrethroids commonly used in repellent vaporizers is the sodium channel that is kept open for long periods of time. This causes prolonged sodium current to flow, thus leading to hyper-excitation of the nervous system. Prallethrin, the chemical compound that is the basic ingredient of any insect repellent, acts on the central nervous system causing headaches, dizziness, and drowsiness, sometimes even leading to asphyxiation and death. Popular brands like ‘All Out’ and ‘Good Knight’ vaporizers use 1.6% of the chemical in their products, prolonged exposure to which is enough to effect permanent brain and nervous system damage.

The presence of deodorized kerosene (96.40%) as a solvent in vaporizers makes it even more dangerous if inhaled regularly. Nausea, an increase in blood pressure, and blood shot eyes are just some of the reasons why these vaporizers need to be avoided. BHT (butylated hydroxytaluene), used widely by all insect repellent manufacturers, can lead to long-term enzyme changes that make the human body more susceptible to cancer. It also has inalterable effects on reproduction. 

The proverbial silver lining in the dark cloud is that there are completely safe methods of keeping irritating mosquitoes at bay, with some help from neighbours and local authorities. Weekly emptying and drying of stagnant water sources in and around houses is a small step that conscientious citizens could take. Proper gradient in drainage systems in residential areas can also help in reducing the proliferation of mosquito population. Mosquito nets are the best bet against an onslaught from all kinds of winged predators. Neem oil based neem-cream or coconut and mustard oil treated with neem could be a cost-effective alternative to chemical repellents. 

A little effort can dispel grave health risks posed by these chemical compounds masquerading as ‘the best way to repel mosquitoes’.