Widespread ‘Mysterious’ Heavy Fog Sparks Fears of Biowarfare Experiments

The appearance of heavy fog over the final week of 2024 in various regions across the country has sparked fears that the U.S. Government is spraying some sort of harmful pathogen on the population. Described as “mysterious” and having a “burning chemical-like smell” by posts on social media, the fog has been likened to a 1950 biowarfare experiment conducted by the U.S. Navy, stoking fears that such an operation is currently underway.

Fog alerts were already in effect for Florida, Iowa, Kansas, Maryland, Minnesota, Nebraska, North Dakota, Oklahoma, parts of Texas, Virginia, West Virginia and Wisconsin when posts regarding the nature of the fog began appearing on social media between December 31 and January 2. One Florida resident, speaking in a video posted to TikTok, said that “the weirdest part is the taste and smell… it smells like after you set off a bunch of fireworks and the taste of the air is toxic. It is super weird.”

Formed when humid air cools to within a few degrees of the dew point, the weather conditions that form fog also tend to trap airborne pollutants, resulting in an increase in the concentration of the offending chemicals. Numerous posts were also made describing flu-like symptoms that the posters experienced after being exposed to the fog, ascribing their conditions to pathogens believed to have been inhaled from the mist, but it is not unusual for the water inhaled from dense fog to “cause respiratory issues such as coughing, shortness of breath, chest pain, congestion and wheezing, especially in people with asthma,” according to the Daily Mail.

“That’s because our lungs are designed to inhale oxygen, not water,” the article continued. “When we inhale the increased moisture content of the air, it can irritate the respiratory system and trigger uncomfortable symptoms,” and “can be especially irritating when it is mixed with airborne pollutants, allergens or other particles.”

At the same time, heavy fog was also reported in regions across Canada; across northern India, delaying trains and over 400 flights at New Delhi’s Delhi Airport; and also disrupting flights at Gatwick and Heathrow airports in the U.K. over the last weekend of 2024.

“There is a lot of fog covering much of England, mainly the south-east and central England, but the rest of the country is seeing quite a bit of thick fog too… It will be pretty murky on Saturday morning and there will still be fog patches that will take a little longer to clear,” according to national weather service meteorologist Liam Eslick.

Although the phenomenon wasn’t accompanied by fearful posts on social media, heavy fog also blanketed parts of the U.S. at the same time last year, along with Canada, China, Egypt, India and Pakistan.

Although they offered no evidence to back up their claims, two posts on X/Twitter likened the fog’s appearance to a mid-century biowarfare study that involved the release of bacteria in the San Francisco Bay area, alluding to a link between the famously-foggy city and the more recent weather occurrence.

“Guys, they dumped a bunch of microbes on the country this week, in the form of fog. I know it sounds tin-foil, but my Spidey senses are telling me they are seeding the skies with pathogens that make us sick. Operation Sea-Spray 4.0,” one December 31, 2024 X/Twitter post stated.

“Did we just suffer another Operation Sea Spray event – The Fog?” said another tweet from January 2, 2025. “Our own military would never expose us to toxins.. actually, they would

“Operation Sea Spray – 1950 San Francisco Bay, California. The US Navy secretly tested out a bioweapon attack on the unsuspecting population”.

Conducted by the U.S. Navy over the course of a week in late September 1950, Operation Sea Spray saw the release of two types of bacteria over San Francisco to evaluate the susceptibility of an urban area to a biowarfare attack involving a deadly pathogen like anthrax. At the time, both species of bacteria were not considered dangerous to humans: one was Bacillus atrophaeus, a microbe that doesn’t cause disease in humans, and was commonly used by the military as a safe proxy for studies on the spread of anthrax. The other, Serratia marcescens, is a common microbe found throughout the environment, and is responsible for the pink or orange slime that forms on unwashed bathroom tiles. Although exposure to S. marcescens is generally safe, it can cause urinary tract (UTI) and catheter-related infections in hospitalized patients.

Although a link hasn’t been definitively proven, it is the latter species that was presumed to have caused an outbreak of 11 rare UTI cases the following month at Sanford Hospital, involving patients that had undergone recent medical procedures; ordinarily, S. marcescens only accounts for 1.4 percent of infections contracted in-hospital, meaning that the sudden appearance of even less than a dozen cases in one facility is notable. Although the majority of those involved made a full recovery, one patient died from his infection.

The existence of Operation Sea Spray went unknown to the public until 1977, when the U.S. Army revealed the operation during a series of hearings held by the U.S. Senate Subcommittee on Health and Scientific Research. While Sea Spray was underway, the military concluded that, given the isolated nature of the cases and their relative commonality to hospitalized patients, the experiment was not the cause of the Sanford cases, it was safe to continue using S. marcescens in future experiments.