Authorities in the Mexican city of Nogales, which borders Arizona, put those entering the country through a curious "disinfectant tunnel" to prevent the spread of COVID-19. 

That way, everyone who arrives in Nogales, Sonora, from the international "Mariposas" checkpoint –including pedestrians– must go through these tunnels where they are sprayed with a disinfectant that keeps the body clean and free of the virus for 24 hours, according to a statement from the municipality of Nogales. 

Health authorities in the region, who have announced that they will install more of these anti-COVID corridors at local border checkpoints, believe that most of the cases of coronavirus recorded in Nogales have been from people crossing from Arizona. 

There is sufficient data that argues the neighboring state's more than 13,000 confirmed infections could've helped with Sonora's 700, and 34 dead. 

However, there are those who assure that these passages are not only useless - if a person is infected with coronavirus, bathing in sanitizing gel does not free them from the disease - but the Mexican Secretary of Health affirms that it can be even dangerous and spread the virus even more. 

In a bulletin from the aforementioned institution, they point out that there is no evidence that these systems are really effective against the SARS-CoV-2 that causes the disease and that "the aerosol generated may facilitate the spread of the virus that could be present on the clothing, hair or belongings of people passing through the tunnel, increasing the risk of spreading the virus."

Beyond the pernicious health effects caused by the inhalation of disinfectant, which can seriously damage the airways and produce asthma attacks or chemical pneumonitis, as well as eye, skin and mucous membrane irritation, this type of safety mechanism induces, according to the Health Secretariat, a "false sense of safety." 

"People can neglect basic prevention measures such as frequent hand washing, use of masks, and maintaining a healthy distance," it says. 

Although Nogales believes otherwise and will continue to plant "washing tunnels" at border crossings, many places in Mexico where they first began installing these anti-COVID passages have backed off pending scientific evidence to corroborate their effectiveness or dangerousness.

Meanwhile, in the Sonora desert, the fight against the pandemic will continue with vaporous showers.