Linda Poon is an assistant editor at CityLab covering science and urban technology, including smart cities and climate change. She previously covered global health and development for NPR’s Goats and Soda blog.
New billboards in Brazil will use the alluring aroma of humans to attract and trap hundreds of hungry insects.
Billboards have come a long way since they were first successfully used in the 1800s to promote the circus industry. Today, they attract passersby with not only straightforward advertisements but also witty ad campaigns and flashy tech. But the latest billboards in Brazil aren’t meant for humans at all.
These billboards target mosquitoes, specifically those that carry the Zika virus. Created by Brazilian ad agencies Posterscope and NBS, the Mosquito Killer Billboard replicates the smell of human sweat to attract, trap, and then kill Aedes aegypti mosquitoes.
“This billboard kills hundreds of Zika mosquitoes every day,” claims the message written on the display in Portuguese.
Devices on the billboards spray a solution of lactic acid and CO2, which reproduces the smell of human sweat and breath. The agencies claim the odor can attract mosquitoes from roughly a mile and a half away. And to make the billboard even more appealing to the insects, fluorescent lights illuminate the display at night. A “catch mechanism” installed at the bottom of the panel sucks the mosquitoes into the billboard, where they eventually die from dehydration.
So far, the agencies have installed two billboards in Rio de Janeiro, according to the BBC, and they’re encouraging other cities to do the same by publishing the entire project online under a Creative Commons license.
But will it work?
The billboards themselves probably won’t play a large role in ridding Brazil from the mosquitoes for good. One recent study from the University of Washington and Oxford University estimates that nearly 300 million people in the Americas alone live in “Zika zones,” or where the virus-carrying mosquito thrives. Worldwide, that estimate jumps to a whopping 2 billion. And eradication experts recently told the Associated Press that it’s highly unlikely that Brazil can “come anywhere near stamping out the pest like it did a half century ago,” largely because of globalization and mass migration in and out of the country. CityLab has reported that urbanization and climate change are largely to blame, as well.
The last time Brazil successfully eradicated the Aedes aegypti mosquitoes, which also carry diseases like dengue fever and yellow fever, was in the 1940s and 1950s, and it took considerable efforts, the AP reports:
"Mata Mosquito," or "Mosquito Killer," brigades would sweep across neighborhoods, going door-to-door, sometimes entering by force, to hunt mosquitoes and squish their larvae. People who lived through the campaigns say the brigades, made up largely of municipal workers, were a year-round presence.
One pest-control expert, Chris Jackson at the University of Southampton, even told BBC that the agencies’ effort could backfire by bringing hungry mosquitoes and curious people closer together in high-density urban areas. But he also said that “anything that can be done to reduce the prevalence of the mosquito is a good thing.”