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.

A deadly case of hantavirus has been confirmed in Israel, while health authorities in the UK and Spain are investigating suspected infections in three individuals, raising fresh concerns over the spread of the rare rat-borne disease.

The case reported from is unlikely to be linked with the ongoing outbreak linked to the MV Hondius cruise ship, currently sailing to the Canary lslands.

The UK is suspecting its third case from a remote South Atlantic island of Tristan da Cunha. Spain is suspecting its first case in a 32-year-old woman who shared an airplane with a MV Hondius cruise ship passenger who later died of hantavirus.

In a good news, suspected cases from Singapore and the Netherlands have reportedly turned negative.

The health officials across 12 countries have joined the WHO in contact tracing efforts. They are:

• Canada
• Denmark
• Germany
• The Netherlands
• New Zealand
• Saint Kitts and Nevis
• Singapore
• Sweden
• Switzerland
• Türkiye
• The United Kingdom
• The United States of America

US CDC Classifies Outbreak As 'Level 3' Emergency

The US Centers for Disease Control and Prevention (CDC) activated its Emergency Operations Centers and has classified the hantavirus outbreak as "Level 3" emergency.

Level 3 is the lowest level of emergency activation and is typical for this stage, ABC News reported.

It also signifies that the risk of the rat-borne virus to the general public remains low. However, the public health agency is actively monitoring the situation.

As per the media report, activating the Emergency Operation Centers signals that an emergency team, consisting of epidemiologists, scientists, and physicians, may have been set up to assist with the response.

No Immediate Public Health Threat To India, says ICMR

After reports of two Indian nationals infected with hantavirus aboard MV Hondius cruise ship, Dr Naveen Kumar, director of the ICMR’s National Institute of Virology (NIV), said that there is "no immediate public health threat” to India.

Dr Kumar said the outbreak appears to be isolated, and that there is currently no evidence of community spread. He stressed that, unlike COVID-19, hantavirus does not spread easily between humans.

“The reported hantavirus cases appear to be isolated ones, and there is no immediate public health threat to India,” he was quoted as saying by news agency PTI.

According to the World Health Organization, the Indian passengers were among a small cluster of suspected infections identified aboard the ship, with health authorities monitoring contacts and taking precautionary measures.

Surveillance Capacity Adequate In India

Kumar said India has sufficient laboratory infrastructure to detect suspected hantavirus cases through the ICMR-NIV and the nationwide Viral Research and Diagnostic Laboratory Network.

“India has diagnostic capacity for hantavirus infection through the ICMR-National Institute of Virology and the nationwide Viral Research and Diagnostic Laboratory Network of 165 labs,” he said.

He said symptoms generally appear one to five weeks after exposure. It includes

fever,

• severe body ache,
• headache,
• fatigue,
• nausea,
• abdominal pain,
• dry cough.

2 Indians Among Crew On MV Hondius Cruise Ship

Two Indians are among 149 people aboard MV Hondius, the expedition cruise ship hit by a deadly hantavirus outbreak that has so far left three passengers dead and eight others infected, according to a BBC report.

The vessel, operated by Oceanwide Expeditions, began its journey from Ushuaia, Argentina, on April 1 and is currently travelling to Spain's Canary Islands on May 10.

According to the World Health Organization, eight people onboard the cruise ship MV Hondius have been infected with hantavirus. Of these, three have died, and five have been confirmed to have the virus. However, more people are likely to be infected, as the disease can take a long time to show symptoms.

The luxury cruise ship was carrying around 150 passengers and crew members from 28 countries.

The nationalities included 38 people from the Philippines, 31 from the United Kingdom, 23 from the United States, 16 from the Netherlands, 14 from Spain, nine from Germany, six from Canada and two crew members from India, BBC reported.

While it is yet not known whether they're infected or not, Dr Puneet Misra, Professor of Community Medicine, AIIMS Delhi, told ANI News Agency that it is likely that the two passengers "might have been exposed to the infection".

He added that "there is no pandemic or epidemic threat" with hantavirus. "The public should not worry. There is no need for panic..."

Follow this page for all latest updates.

US President Donald Trump is hopeful that the deadly hantavirus outbreak is very much under control. However, questions are mounting as his administration cut funding to study the rat-borne virus last year.

According to the World Health Organization, eight people onboard the cruise ship MV Hondius have been infected with hantavirus. Of these, three have died, and five have been confirmed to have the virus. However, more people are likely to be infected, as the disease can take a long time to show symptoms.

Speaking to reporters Thursday, Donald Trump sought to reassure Americans that the situation appeared contained.

“It’s very much, we hope, under control,” Trump said during an impromptu appearance near the Lincoln Memorial Reflecting Pool in Washington, DC. The President added that the administration planned to release “a full report” on the incident and said health officials were continuing to study the outbreak closely.

“We’re doing the best we can,” Trump told reporters when asked whether Americans should worry about the wider spread of the virus.

Notably, at least 23 passengers from the hantavirus-affected MV Hondius cruise ship returned home, including several to the United States — and one of them has already fallen ill.

Hantavirus Cases In The US?

The travelers reportedly did not know they had been exposed to the deadly virus when they disembarked during the ship’s stop at Saint Helena, a remote island in the South Atlantic, on April 23.

People in at least five US states — Georgia, Arizona, California, Texas, and Virginia — are reportedly being monitored for possible hantavirus exposure, though none have shown symptoms.

According to Dr. Jay Bhattacharya, Director of the US National Institutes of Health (NIH), “Hantavirus is not spread by people without symptoms, transmission requires close contact, and the risk to the American public is very low.”

CDC Cuts On Hantavirus Research

Behind the public reassurance, however, health authorities are confronting a situation that remains poorly understood — particularly because the Trump administration last year cut funding to study the virus behind the deadly cruise ship outbreak, and also fired scientists in key positions who were tracking viruses.

The Centers for Research in Emerging Infectious Diseases were designed to study viruses that could jump from animals to people, including hantavirus, but in 2025, the National Institutes of Health said the work would not continue.

Further, in its 2026 budget request, on one hand, the Trump administration said it planned to refocus the CDC on outbreak investigations and preparedness; on the other hand, it proposed eliminating about $750 million in preparedness grants that states rely on to cope with natural and man-made disasters, including outbreaks.

It also zeroed funding for the Hospital Preparedness Program, which strengthens healthcare systems to respond to emergencies, saying the program “has been wasteful and unfocused”, the New York Times reported.

Notably, the effects of the Trump administration’s cuts to infectious disease research are also being felt globally. South Africa has the capacity to sequence the hantavirus partly because of investments made by previous US administrations through the President’s Emergency Fund for AIDS Relief (PEPFAR), Dr. Carlos del Rio, an infectious disease expert at Emory University, told reporters.

However, the Trump administration has significantly reduced support for South Africa’s research system and is pulling back funding for PEPFAR.

“I worry that as we disinvest in global health, we’re losing our capacity — our global capacity — to deal with diseases,” Dr. Del Rio said.

The six-week-long incubation period of Hantavirus is a matter of concern, but the rat-borne disease is certainly not a large epidemic, said the World Health Organization today.

At a media briefing, the WHO Director General Dr Tedros Adhanom Ghebreyesus, expressed concerns about the time taken for the symptoms of the disease to appear.

He noted that so far the disease has been limited to the 150 people who traveled on board the MV Hondius ship. Of these, only 8 people have been infected - 3 have died, and 5 have been confirmed.

A case has been reported in a person who disembarked from the ship, without having the symptoms, and some have self-isolated to prevent the risk of spreading.

Among those on board the ship, now travelling to the Canary Islands, "currently no one is symptomatic".

However, "with a six-week incubation period, more cases are expected to be reported".

Countries involved in the contact tracing efforts of people who disembarked at St. Helena Islands include Canada, the Netherlands, Singapore, Turkey, the UK, and the US, the WHO chief said.

WHO infectious disease epidemiologist Maria Van Kerkhove reiterated that the disease spreads only among close, prolonged contacts or those providing care, as seen in the case of the doctor who got infected on board.

The WHO also noted that the disease is unlikely to become a large epidemic, as it's an isolated case occurring in a closed environment. However, public health measures like contact tracing and testing are key to preventing any further spread.

According to the WHO, the outbreak of the rat-borne disease among people aboard the MV Hondius ship after it left Argentina on April 1 was caused by the Andes strain.

Speaking to HealthandMe, Dr. Gautam Menon, Epidemiologist and Professor of Physics and Biology, Ashoka University, Delhi-NCR, said that the long incubation period is likely to complicate the spread of the hantavirus.

"What complicates matters is that incubation periods - the time between getting infected and symptoms showing - are large, up to several weeks, so passengers and their contacts will have to be quarantined for a long period before they can be declared safe." The expert said.

Is Hantavirus Similar To COVID-19?

Ven Kerkhove said that hantavirus causes severe respiratory issues, but it is still not the same as SARS-CoV-2.

This is not a new virus and is completely different from SARS-COV-2. It has caused similar outbreaks in Argentina in 2018, where contact tracing and other public health measures contained the spread.

"The outbreak of Hantavirus on a cruise ship has generated significant anxiety around the world, evoking memories of cruise ships affected by COVID-19 in the first phase of the pandemic. However, this is a different virus that is not known to spread efficiently from person to person. Its characteristics are already well-documented, unlike the SARS-CoV-2 virus, which was an unknown organism until then," Dr. Rajeev Jayadevan, Ex-President of IMA Cochin and Convener of the Research Cell, Kerala, told HealthandMe.

"The current cases do not indicate a pandemic threat, but they underline the growing importance of surveillance of zoonotic diseases. Strengthening rodent control, environmental hygiene, and early detection systems remains essential to prevent localized outbreaks and public panic. There is neither a proven treatment for its cure nor is there any vaccine," added Dr.Ishwar Gilada, Mumbai-based infectious disease expert.

How does The Hantavirus Affect The Human Body?

Hantavirus infection is caused by the hantavirus, which belongs to the Hantaviridae family. It is is rare but can be life-threatening.

The infection presents with initial symptoms resembling the flu and has a relatively high mortality of about 40%.

Also read: Hantavirus Sparks Global Alert As Countries Race To Trace Contacts; WHO Says Risk Low

Even though this virus is not believed to spread very efficiently, it would have done so far more easily in the enclosed environment that the ship provided, the experts said.

Dr Neha Rastogi, Senior Consultant, Infectious Diseases, Fortis Memorial Research Institute, Gurugram, told HealthandMe that it can be contracted by coming into contact with rodent saliva, urine, and feces.

Hantavirus can cause infection - 2 syndromes: hantavirus pulmonary syndrome and haemorrhagic fever that may quickly develop into severe respiratory illness, as flu-like symptoms (fever, muscle aches, and fatigue) occur before developing serious respiratory symptoms (dyspnea) that may require respiratory assistance.

"On rare occasions, it can also spread from person to person through close contact. Rapid diagnosis and intensive medical treatment are critical for a successful outcome," Dr Rastogi said.

"Preventative measures include proper personal hygiene, avoiding contact with rodents or rodent-inhabited areas; using PPE when cleaning; and ensuring the area is well-ventilated," she added.

Although hantavirus infections can cause severe respiratory illness with high mortality, confirmed human cases globally remain relatively uncommon, Dr Gilada told HealthandMe

"The pneumonia syndrome caused by the virus is due to excessive permeability of blood vessels, resulting in fluid accumulation. It is managed with expert supportive care while the lungs recover, as there are currently no known antivirals or vaccines available for the Andes virus. By carefully tracking contacts and isolating those who might be infected, the virus can be stopped in its tracks, bringing this outbreak under control," Dr Jaydevan said.