Mysterious Fog in the US , Canada and UK: A dense, eerie fog with a "burning chemical-like smell" has spooked a good part of North America and parts of the United Kingdom and Canada. With social media amplifying all concerns, this phenomenon has sparked attention across all social media platforms. However, at the heart of this mysterious fog are a conjunction of natural events, social psychology, and environmental conditions that culminated in all the conspiracy theories and public health fears. Here's a closer look at the mysterious fog, its potential causes, and the societal response it has triggered.

Fog that Feeds Fear

The first reports of this "mysterious fog" came in from Florida where a resident said that they experienced respiratory symptoms, feverish warmth, and stomach cramps after contact with the fog. Similar stories started flooding social media, and within a day or two, a sinister force seemed to sweep across the United States, Canada, and parts of the UK. From Texas to Minnesota, people reported weird odors and health issues that they thought were linked to this bizarre atmospheric event.

Some witnesses were said to see "white particles" swirling through the air; theories ranged from a chemical attack or experimental weapon to drone-related chemical dispersals and references to historical military experiments, such as the infamous 1950s "Operation Sea-Spray."

Fuel to the fire were added when videos and posts, hundreds of thousands in number, began circulating on social media sites like TikTok and X (formerly Twitter) speculating on the origin of the fog. Hashtags like #ToxicFog went trending for days. Hysteria created a self-reinforcing loop in which every post spurred further scrutiny and fear.

Scientific Explanation of the Dense Mysterious Fog

1. What is Fog?

Fog is essentially a low-lying cloud formed when the air temperature cools to its dew point, causing water vapor to condense into tiny droplets or ice crystals. Several types of fog—advection fog, radiation fog, and valley fog—can form depending on conditions such as warm, moist air moving over cooler land or when temperatures plummet rapidly under clear skies.

2. Why the Chemical Smell?

Such chemical-like smell as reported during the occurrence of fog events is sometimes attributed to air pollution. It acts like a sponge, where it absorbs these pollutants, which include sulfur dioxide and nitrogen oxides, among others, that emit from industries. This mixture, therefore, leads to a stench that could be mistaken as unnatural or even toxic.

Also Read: Health Concerns Rise As US, Canada, and UK Come Under The Blanket Of Thick, Dense, Toxic Fog

3. What are the Health Concerns?

High moisture levels from fog can significantly exacerbate symptoms related to respiration, but especially in already predisposed asthmatics and allergy patients. The connection of these symptoms with actual fever, stomach cramps, and puffy eyes is too remote. Experts assume that the irritating effects of entrapped pollutants trapped in fog tend to affect more the eyes and throat rather than the rest of the body affected by some report.

Psychological Effects of Mass Panic Caused by Social Media

Social media amplified a natural weather event into a health epidemic. It made the personal experience of individuals become a cause for fear and speculation, a domino effect.

According to psychologists, this is a concept of selective perception, wherein once people's attention is drawn to environmental anomalies, they begin to notice them. This mirrors earlier panics, such as the Seattle windshield pitting panic of 1954. Then, atomic bomb testing caused fear in many and started to have people looking at their windshields for small marks that they had not seen before. Likewise, postings on the strangeness of the fog probably increased public awareness and suspicion, with people looking to attach unrelated symptoms to the phenomenon.

The fog hysteria shares a commonality with other instances of mass panic, such as the "drone sightings" of recent years or the Cold War-era fears of biological warfare.

Also Read: Mysterious Fog Is Making Americans Sick

These events underscore how fear can cloud judgment, especially when amplified by social media and sensationalist headlines. While historical cases, such as "Operation Sea-Spray," offer concrete evidence of the existence of unethical experiments, the jump from a natural weather condition to theories of chemical attacks exemplifies a more modern trend of connecting unrelated dots, all wonderfully seeded in distrust and anxiety.

Despite the swirling rumors, meteorologists and scientists are in agreement that the mysterious fog is not as alarming as it seems. It is well known that fog traps and amplifies pollutants, especially in urban and industrial regions. Moreover, winter months are the most conducive for fog formation, so its recent prevalence is unsurprising.

On the other hand, environmentalists advise that the fog should wake everyone up to increased levels of pollution. The reported odors and health irritations could be just symptoms of far deeper systemic issues like industrial emissions and lack of control over air quality.

The authorities must be transparent in their communication to combat misinformation and allay public fears. Governments and environmental agencies must provide timely updates on weather phenomena, air quality, and health risks. Initiatives like real-time pollutant tracking and public education campaigns can help demystify natural occurrences while addressing valid environmental concerns.

The mysterious Canada fog is a compelling case study in how environmental events intersect with psychology and societal dynamics. While rooted in natural phenomena, the fog became a vessel for collective fears, amplified by modern technology and historical anxieties.

In this information era where communication occurs at an almost lightning pace, the fog becomes a metaphor that reminds everyone about scientific literacy, environmental responsibility, and an effective balance when considering public concern. Whether perceived as a marvel of nature or as a tale that serves to teach, it left a very powerful mark in people's minds.

Toxic air persisted for months after the fatal 9/11 attacks on the World Trade Center, which killed more than 2,000 people, even as officials played down the health risks at Ground Zero in New York’s Manhattan, according to a trove of newly released files.

New York City Mayor Zohran Mamdani today released more than 170,000 documents from government agencies related to post-9/11 air quality and health risks. He accused officials of lying to the public about the dangers of toxic air at Ground Zero, where the World Trade Center towers collapsed in 2001.

“People got sick because the leaders they trusted lied and told them they were safe to breathe in toxic air,” Mamdani said at a news conference with survivors.

“As the years pass and the human toll grows, we reckon with the cost of September 11th whenever another New Yorker is stolen from us too soon. Now, close to 25 years later, more people have died from 9/11-related illnesses than were killed on the day itself.

“The very least our city owes the families, survivors and first responders whose lives were forever changed by the September 11th attacks is transparency and accountability. That is why I am proud that our administration has launched the City’s first public records portal dedicated to the environmental and health impacts of 9/11 and reached a settlement in these lawsuits,” said Mayor Mamdani.

What Do the Documents Reveal?

The files, released Tuesday and made available through an online portal, include 68 boxes of documents that were discovered last year, the Harding Memo and records concerning World Trade Center 7.

The 68 boxes had not been located until 2025, despite multiple Freedom of Information Law (FOIL) requests.

One key document is the October 2001 “Harding Memo”, in which an aide warned former Deputy Mayor Robert Harding, who served under then-Mayor Rudy Giuliani, that the city could face as many as 35,000 legal claims over its response to the attacks.

The memo states that the city could face lawsuits because health advisories had caused individuals “to return to the area too soon (causing toxic exposure or emotional harm).”

“There was poison in the air and on the ground and in the window sills and in your air conditioners and covering your pets and your clothes, and it stayed there for months. Everyone knew. And now it's very clear that the city knew as well,” said advocate Jon Stewart, CBS News reported.

Days after the attacks, city and federal officials, including the US Environmental Protection Agency (EPA), declared that the air near the Twin Towers was safe. Subsequent research, however, found that people had been exposed to toxic chemicals.

Christine Todd Whitman, who headed the EPA at the time, later apologized for the declaration, saying the agency “did the very best we could at the time with the knowledge we had,” BBC reported.

What Happened On 9/11?

In Lower Manhattan, the plane crashes and subsequent collapse of the Twin Towers created massive dust clouds that filled the air. Hundreds of highly populated city blocks were covered with ash, debris and harmful particles, including asbestos, silica, metals, concrete and glass.

According to the US CDC, fires within the debris pile and the collapse of 7 World Trade Center continued to burn through the end of December 2001, with flare-ups continuing into 2002. The fires released carcinogenic combustion by-products, while contaminants remained in Lower Manhattan and parts of Brooklyn for an undetermined period after 9/11.

Responders, local workers, residents, students and others faced potential exposure in the early days and in the months that followed. They could have been exposed to residual materials indoors and outdoors, as well as toxic gases, smoke, vapozrs and combustion by-products from continuing fires.

Manila is witnessing a sharp rise in leptospirosis cases, with infections now crossing the city’s epidemic threshold following widespread exposure to floodwaters in August.

Nearly 1,000 cases have been reported in Manila this year, with the number rising rapidly over the past two weeks, Manila City health officer Grace Padilla told ABS-CBN News.

Padilla said the city’s attack rate has reached three, signaling a high level of transmission in the affected population.

Health officials expect cases to continue rising as more residents who came into contact with floodwater in late August seek medical attention.

Hospitals Face Growing Pressure

The surge in cases has also put additional pressure on hospitals across Manila. The city is also providing post-exposure prophylaxis at 44 health centers to people considered at risk following exposure to potentially contaminated floodwater, the report said.

The situation extends beyond Manila. Metro Manila has recorded at least 1,961 cases, with Manila and Quezon City reporting the highest cumulative numbers, followed by Caloocan and Taguig.

Philippines Records Hundreds of Deaths

The outbreak is part of a wider national burden. From January 1 to August 29, the Philippines recorded 6,253 leptospirosis cases and 378 deaths, according to the health department’s epidemiology bureau.

Why Floodwater Raises Leptospirosis Risk

Leptospirosis is one of the most prevalent zoonotic diseases worldwide, often linked to poor sanitation and agricultural practices that involve contact with animals or contaminated water.

The bacteria can survive in contaminated water or soil for weeks to months, primarily spreading through the urine of infected animals. Humans can contract the disease through direct contact with infected urine or through contaminated food, water, or soil.

Flooding can increase the risk of exposure by spreading contaminated water through homes, streets and communities.

What Are Symptoms Of Leptospirosis?

Symptoms typically develop 2 to 30 days after exposure and can range from mild to severe. Initial signs often include high-grade fever, red eyes (conjunctival suffusion), calf tenderness, headache, dry cough, nausea, and diarrhea.

In more serious cases, the infection can lead to complications such as jaundice, kidney or liver damage, meningitis, respiratory issues, and hemorrhages.

The health authorities in Manila shared that people who have recently been exposed to floodwater should watch for symptoms such as fever, headache, muscle pain and joint pain and seek medical attention if they develop them.

The infection can be treated with antibiotics, including doxycycline, when prescribed by a doctor.

What Precautions Should Be Taken?

According to the Centers for Disease Control and Prevention (CDC), it is essential to avoid wading through dirty rainwater, especially during the rainy season, and to wear gumboots in such conditions.

Proper care of any injuries or cuts is crucial, and frequent handwashing, particularly after handling food or working in potentially contaminated environments, is highly recommended. Additionally, individuals should avoid contact with animals that appear sick or are known carriers of the bacteria.

Weight loss surgery may do more than help women living with obesity lose weight. A new study has found that metabolic bariatric surgery can improve menstrual cycles and several reproductive symptoms linked to Polycystic Ovary Syndrome, now renamed as Polyendocrine Metabolic Ovarian Syndrome (PMOS).

Researchers from the University of Surrey followed 84 women aged 18 to 45 who underwent bariatric surgery, including 49 gastric bypass and 35 gastric sleeve procedures, for 24 months. Another 18 women with obesity who did not undergo surgery were included for comparison. The findings were published in Obesity Surgery.

Bariatric Surgery Improved PMOS Symptoms

Women who underwent surgery lost more than 30 kg on average at both 12 and 24 months after the procedure. But researchers also observed improvements in reproductive health. Women who had previously experienced irregular periods reported more regular menstrual cycles after surgery. The number of women with polycystic ovaries also fell significantly, with the condition persisting in only 10% of those affected after 24 months.

Another common PMOS symptom, hirsutism or excessive facial and body hair, had resolved in the women reporting the condition by 12 months.

Obesity and PMOS can team up in a way that worsens metabolic and reproductive problems. Insulin resistance and hormonal changes associated with excess weight can contribute to irregular ovulation, menstrual irregularity and difficulty conceiving.

Also read: PCOD vs PCOS vs PMOS: Why The Condition’s Name Has Changed Over Time

Weight Loss Could Improve PMOS Symptoms

The researchers suggest that reducing obesity may help correct some of the hormonal and metabolic disturbances affecting reproductive health.

Dr Kathryn Hart, co-author of the study and Associate Professor in Nutrition and Dietetics at the University of Surrey, said: “Dysregulated hormone levels, irregular periods and conditions such as polycystic ovaries are impacted by obesity. By reducing this, what we have seen is that it can lead to improvements without the need for medication,” she added.

Despite promising results, this does not mean bariatric surgery is a treatment that every obese woman with PMOS should undergo.

The procedure is generally considered for people with obesity who meet a certain clinical criteria. Also it carries its own risks and nutritional considerations that are important.

Also read: From Insulin Resistance to Fertility: Understanding the Metabolic Side of PCOS

Fertility May Return Quickly After Surgery

The researchers also highlighted an important finding for women who may be planning pregnancy. Seventeen women in the study had healthy pregnancies following surgery.

The researchers said reproductive counselling and preconception care should be incorporated into care after bariatric surgery, particularly because fertility can improve as menstrual cycles and ovulation become more regular.

Professor Martin Whyte, co-author and Professor of Metabolic Medicine at the University of Surrey, said many people undergoing bariatric surgery are women of reproductive age who may be considering pregnancy.

“So much remains unknown about the impact of this type of surgery on women who are planning to have children,” he said, highlighting the need to understand when the ideal time to conceive may be after surgery.

Importance Of Combating PMOS-Related Obesity

The study adds to growing evidence that treating obesity can improve some reproductive symptoms of PMOS.

A 2026 systematic review and meta-analysis also found that bariatric surgery was associated with reductions in menstrual irregularities, hirsutism and several reproductive hormone abnormalities.

But bariatric surgery is not a cure for PMOS. PMOS is a complex hormonal and metabolic health condition and its symptomscan vary considerably between women.