The search for a safer mosquito spray


Ok. so you’re camping with your friends
and the mosquitoes are driving everyone crazy. You have some bug spray with DEET and it really
works great But is it safe to spray this chemical all
over yourself? Today, studies show that DEET has harmful
effects to cells in our bodies. It can dissolve nylons. It can dissolve plastics. It can dissolve your watchband. This is Anandasankar Ray, he’s trying to
find safer AND more effective ways to repel insects. Insect repellant that we commonly use called
DEET has remained unchanged since the 1950s. This is actually kind of crazy. Bug spray has pretty much stayed the same
for 70 years. And when Scientists first developed DEET they
didn’t really understand why it repelled mosquitoes. And it’s hard to improve something when
you don’t even understand how it works. So first, Ray wanted to figure out how mosquitoes
smell. So the mosquito has an incredibly sensitive
nose. We emit quite a substantial amount of carbon
dioxide and this gets carried downwind in the shape of plumes. And the mosquito when it comes across one
such plume, it starts to move in closer and closer towards us and recognizes that oh,
this is a human being that is going to be a source of blood, and makes a beeline for
us. And once Ray understood what attracts mosquitoes
to people he turned his attention to repellants to understand what chemical features caused
this repellency. He looked at a mosquito’s nose to see which
receptors detect DEET. And then using this really powerful computer
he took all of this data and found some alternatives. We were able to very rapidly screen nearly
half a million chemicals in one afternoon and identify 1000 new DEET substitutes. And one hundred of these are already considered
safe by the FDA. And these aren’t going to destroy fabrics
like DEET. These are chemicals that are actually found
in fruits, found in plants, and some of these are used in our food for flavoring. So right now, he’s developing a lotion that’s
as strong as DEET, but uses natural compounds We have some that smell like orange blossoms,
some that smell like sandalwood. And really what he’s doing here is trying
to find scents that WE think smell really nice, but mosquitoes don’t like. And Mosquitoes aren’t just annoying when
you’re camping — they can be really dangerous. Nearly a BILLION people worldwide are affected
by mosquito-borne diseases like Zika, West Nile, Dengue and Malaria. And so I am hopeful that this approach will
lead to interventions that could be useful in the field and perhaps not only help protect
us in our backyard barbeques, but also help have an impact on malaria, in Africa. And these same compounds also repel bedbugs,
ants and even agricultural pests that destroy the food we grow. So it may not seem important or glamorous
to understand just how a mosquito’s nose works, but this research has opened up a lot
of new possibilities.