Mysterious fog sweeping US sparks bioweapon fears amid alarming echoes of secret 1950 military program

A thick, ‘mysterious’ fog has descended on much of the US, sparking fears of a new ‘Operation Sea Spray’.

In September 1950, the US Navy spotted huge amounts of bacteria in the air for a week two miles off the coast of San Francisco, California.

The purpose of this secret biological warfare experiment was to find out how vulnerable major American cities like San Francisco would be to a biological warfare attack by terrorists.

The bacteria used were Serratia marcescens, which can cause respiratory problems and meningitis, and Bacillus atrophaeus, which can be fatal to immunocompromised individuals. At the time, the Navy believed these bacteria were harmless to humans.

But as Bay Area residents rushed to the hospital, it became clear that wasn’t the case.

After inhaling thousands of bacterial spores, eleven people went to Stanford Hospital near San Francisco with very rare, serious urinary tract infections that doctors ultimately determined were caused by the experiment.

One patient, a man named Edward Nevin, who was recovering from prostate surgery at the time, died.

Now, 75 years later, some Americans fear this will happen again, claiming an “unnatural” fog with a “burning, chemical-like odor” has plagued their communities in recent weeks.

Concerned citizens have flooded social media with videos of what appears to be white particles raining down and swirling through the air.

Some witnesses also claim that the fog has caused health symptoms similar to a respiratory illness.

A Florida resident told DailyMail.com that they stopped at a gas station for about ten minutes and started feeling sick.

“Within about an hour, I kept sneezing over and over again for about three hours, and my eyes were really swollen,” she said.

‘I felt very warm and felt like I had a fever, and my stomach was cramping.’

A woman in Kansas also reported that “massive amounts of chemtrails” flew over the area in a week, followed by a dense fog.

And a California resident shared on X Monday: “Here in SoCal, unusual fog the last few days. Strange smells, but I’ve noticed the smell for months, it burns my nose. It seems like an all-out attack from the air in the last few days.”

Parts of Texas, Wisconsin, Iowa, Maryland, Virginia, West Virginia, Nebraska, Kansas, Oklahoma, North Dakota, Florida and Minnesota were under fog warnings when the bizarre reports surfaced this week.

Similar experiences have also emerged in parts of Canada and Britain, causing widespread concern.

Conspiracy theories are swirling, with people suggesting the fog could be some sort of chemical weapon or linked to the drones that mysteriously ravaged the country in December.

The latest theory is that the US government is behind the fog and may be testing a new type of biological weapon, similar to Operation Sea Spray.

“Guys, they dumped some microbes in the country this week, in the form of fog,” an X user posted on Tuesday.

“I know it sounds tin foil, but my Spidey senses tell me they’re seeding the air with pathogens that are making us sick. Operation Sea-Spray 4.0 (24-31 December 2024).’

Another asked: ‘Have we just experienced another Operation Sea Spray event: The Fog?’

However, the National Weather Service (NWS) issued a dense fog advisory for multiple states at the time of these reports, indicating there is a scientific explanation for the fog.

Although the appearance of the “white particles” of fog may seem unusual, fog is a visible aerosol composed of small water droplets or ice crystals floating in the air at or near the Earth’s surface.

By shining a light into the mist, these particles become visible.

As for the “chemical” smell people have described, the fog can absorb and trap polluted air near the Earth’s surface, acting as a carrier for car exhaust, industrial emissions and other airborne chemicals.

“When fog forms, sulfur oxides, nitrogen oxides, and other pollutant gases are absorbed or ‘swept away’ by fog water droplets,” explains Rudolf Husar, an atmospheric scientist at Washington University, in an article for NASA Earth Observatory.

Additionally, odors become stronger in humid air because the water droplets capture the odor-causing molecules, allowing them to linger longer and remain concentrated.

This is not unusual for this time of year.

Fog forms when temperatures cool to the dew point, or the temperature at which the air can become completely saturated with water.

Much of the fog currently hanging over the US is likely advection fog, which typically forms in winter when warm, moist air flows over colder land.

This is often seen in the southern or central US, where many affected states are located.

Some states, such as Minnesota, also experience radiation fog that occurs in air with a high dew point.

It occurs when the sky is clear, the temperature reaches the dew point, and the wind is low enough to cause minimal atmospheric mixing.

Although fog usually looks like a smooth gray mist, shining a light directly through it causes the light to spread from each individual water droplet that makes up the fog, reflecting that light back to your eyes.

This causes each droplet to appear as a tiny ‘particle’ within the light beam, as evidenced by many of the photos and videos recently shared online.

The “chemical” smell associated with this recent fog likely does not come from the fog itself, but rather from pollutants already present in the air when the fog formed.

The respiratory disease-like symptoms that people report can also be explained by natural fog.

Multiple studies have shown that fog can cause breathing problems such as coughing, shortness of breath, chest pain, congestion and wheezing, especially in people with asthma.

That’s because our lungs are designed to breathe oxygen, not water. When we breathe in the increased moisture content of the air, it can irritate the respiratory tract and cause uncomfortable symptoms.

Fog can be especially irritating if it is mixed with airborne pollutants, allergens, or other particles.

So this ‘mysterious’ fog is not that mysterious at all. People in the US are most likely experiencing a completely normal winter weather event, as there is no evidence to suggest otherwise at this time.