Volunteers from Sonko Rescue Team, an NGO privately funded by Nairobi Governor Mike Sonko, fumigate a street to curb the spread of COVID-19 during a joint operation with Nairobi county during curfew at a residential area in Nairobi, Kenya, on April 6, 2020. (Photo credit: Photo by YASUYOSHI CHIBA/AFP via Getty Images)

Since the beginning of the coronavirus outbreak, news coverage in many countries has featured ominous photos of sanitation workers wearing hazmat suits carrying flamethrower-style devices fogging the streets with unknown chemicals.

The machines are called thermal foggers, and they are normally used to dispense oil-based chemical solutions in factories, food processing plants, greenhouses, livestock barns, and other industrial environments where getting a disinfectant or other chemical to cover all surfaces evenly wouldn’t be possible by other means. But since the coronavirus began spreading, they’ve become common in streets, buildings, and other public spaces around the world.

Thermal foggers aren’t the only way that governments in Indonesia, Russia, Afghanistan, and other (largely developing-economy) nations are dousing their land and people with disinfectants.

Drones with tanks and sprayers attached, trucks with firehoses, and troves of workers armed with mops and buckets are being used to spray, soak, scrub, and fog their way to public safety.

Misplaced emphasis and mixed messages

Despite the impressive visuals and bold message that the flamethrowers and firetrucks in the streets send, it may not be the right message.

According to Teo Yik Ying, Dean of the Medical School at the National University of Singapore, these large-scale disinfection campaigns present numerous risks to public safety.

First is the fact that they don’t do much to actually combat the spread of the virus, as it is not contracted from road surfaces, the exterior of buildings, or the open air in outdoor spaces. The coronavirus typically spreads from high-contact surfaces such as doors, chairs, and electronic devices or from direct human-to-human interactions. Disinfecting the streets will have no positive impact on the spread.

Second is that such highly visible measures might lend the general public the wrong impression that their neighborhood or their city has been sanitized and therefore there is less need for personal and household sanitation practices such as avoiding crowded public spaces or the frequent washing hands. Given that the public measures don’t really work but the personal measures they dis-incentivize do, this is doubly bad.

Third is the fact that disinfectants — especially lower-grade industrial ones more likely to be used in developing economies — are typically toxic to the environment. In the photos and videos we’ve collected from around the world, thousands of gallons of chemicals can be seen permeating the air, pouring down street drains, and seeping into the ground. What impact will the accumulation of these chemicals have on the surrounding environments?

Last but not least is the fact that these same chemicals can be detrimental to human health if administered in overly high concentrations or in manners that were not intended. This is to say nothing of the mineral oils in which the chemicals are usually dissolved and distributed. Highly refined mineral oils can be safe for use around humans, but low-grade industrial mineral oils produced as a byproduct of petroleum refining are classified as group one carcinogens that cause cancer in humans. In Serbia, residents were forced to walk through disinfectant spray-downs just to enter the local grocery. Which types of mineral oils and chemicals are these countries using, and what impact will the accumulation of these chemicals have on human bodies?

A cure, but with severe side effects

While governments are struggling to contain the spread of the virus and to reassure their populations that they are taking action, the long-term side effects of some of these methods may outweigh the benefits.

If personal responsibility for bodily sanitation and collective adherence to social distancing are compromised by a sense that the government is taking care of the problem, no amount of chlorine or ammonium will keep people safe. If urban landscapes and natural environments are degraded further than they already have been, it may take decades for natural life to take root again.

Worst of all, it’s not impossible that many people will suffer physical side effects — or worse, be severely poisoned — by the toxic cleaning substances that now surround them.

As the once-novel coronavirus loses its novelty, the international medical community will hopefully align around a counter-contagion playbook, and countries from Serbia to Afghanistan can put away their big machines, or at least trade them in for smaller ones.

This image shows a smaller version of a thermal fogger being used at a Seattle, Washington, retail store to quickly disinfect the buttons on a high-traffic ATM machine. There is a time and place for all things, but reaching for big machines to make big, but often wrong, statements will only make things worse.

Jaime Casady uses an electrostatic sprayer to disinfect the Uncle Ike’s pot shop, during the coronavirus disease (COVID-19) outbreak, in Seattle, Washington, U.S. March 26, 2020. REUTERS/David Ryder