Public Health

Authors:

• Bhavini Gohel | Clinical Associate Professor, Cumming School of Medicine, University of Calgary
• Muskaan Muse Laroyia | MSc Candidate & Graduate Researcher, Neuroscience, Hotchkiss Brain Institute, University of Calgary

Anyone who has experienced wildfire smoke knows how it can leave you with a scratchy throat, stinging eyes and impact your lungs. However, smoke can also affect your brain. Tiny airborne pollutants found in smoke have been linked to increased risk of stroke, dementia and flare-ups in neurological diseases like multiple sclerosis (MS).

Alongside harmful gases and heavy metals, wildfire smoke contains fine particulate matter, also known as PM2.5. These tiny particles can travel deep into your lungs, slip into your bloodstream and even reach your brain. Some even bypass the lungs entirely, entering the brain directly through the nose.

After entering the brain, these toxins can cause inflammation and stress, damage nerve cells and even accelerate cognitive decline. Studies have linked exposure to air pollution to an increased risk of stroke and dementia. Even short-term spikes in smoke exposure, like those during wildfires, lead to a surge in emergency visits for strokes, especially among people over 65.

A 2022 experiment had thousands of adults participate in an online attention task under smoky conditions. It found that just a three-hour spike in fine particulate matter, typical of a heavy smoke episode, led to measurably worse attention scores. This fits other evidence that breathing smoke makes people mentally foggy, forgetful or fatigued.

As cannabis use among youth rises in Canada — and THC potency reaches record highs — emergency departments are seeing a surge in cases of a once-rare condition: cannabis hyperemesis syndrome (CHS).

Characterized by relentless vomiting, abdominal pain and temporary relief through compulsive hot showers or baths, CHS is increasingly affecting adolescents and young adults. Yet few people — including many clinicians — know it exists.

Canada ranks among the highest globally for youth cannabis use, with 43 per cent of 16-19-year-olds reporting use in the past year. Usage peaks among those 20–24 years, with nearly half (48 per cent) reporting past-year use.

This rise in regular, heavy use coincides with a 400 per cent increase in THC potency since the 1980s. Strains with THC levels above 25 per cent are now common. As cannabis becomes more potent and accessible, clinicians are seeing more cases of CHS, a condition virtually unheard of before 2004.

CHS unfolds in three phases:

1. Prodromal phase: Nausea and early morning discomfort begin. Users increase cannabis consumption, thinking it will relieve symptoms.

2. Hyperemetic phase: Intense vomiting, dehydration and abdominal pain follow. Hot showers or baths provide temporary relief — a hallmark of CHS.

3. Recovery phase: Symptoms resolve after stopping cannabis entirely.

Diagnosis is often delayed. One reason is because CHS mimics conditions like gastroenteritis or eating disorders, leading to costly CT scans, MRIs and gastric emptying tests. One telltale sign — compulsive hot bathing — is frequently overlooked, despite its strong diagnostic value.

Youth face unique risks. The brain continues to develop until about age 25, and THC exposure during this critical window can impair cognitive functions like memory, learning and emotional regulation. Heavy cannabis use is associated with heightened risks of anxiety, depression, psychosis and self-harm.

I was glad to hear from BBC crowd science (the linked show) that I’m not alone in hearing a hum. People around the world hear a low frequency (50 Hz) hum.

What I hear often when waking up in the morning is a high pitch buzz, comparable to the sound of your ears ringing the day after a concert. My theories:

• it’s microwave radiation, perhaps from wi-fi
• the eardrum itself is making noise due to a physiological condition, despite not being around loud noise (BBC mentions this as well)

I recall hearing about a woman who could hear wi-fi, to the surprise of scientists who would emit supersonic sounds and the woman would raise her hand to indicate when she hears a sound. IIRC, she moved to live in a small region where wi-fi is banned to prevent interference with an array of radio telescopes.

Here’s another link to past stories:

• https://www.tinnitusjournal.com/articles/manifestations-of-a-lowfrequency-sound-of-unknown-origin-perceived-worldwide-also-known-as-the-hum-or-the-taos-hum.html
• https://www.theguardian.com/cities/2019/mar/16/can-you-hear-the-mysterious-global-hum-apparently-many-of-you-do

I am not quite sure I would call the hum low pitched. What I hear is very similar to the ringing ears experience after a concert. Isn’t that a high pitch?

I have to say I’m bothered that the research for this requires participants to use Google. I will not submit records to the project because of that.

cross-posted from: https://sh.itjust.works/post/39836237

Recent Veritasium video on per- and polyfluoroalkyl substances.

I've copied it below:

Your Excellency, Dr Khaled Abdel Ghaffar, Minister of Health and Population of Egypt,

Distinguished officials,

Representatives of the Egyptian Vaccine Manufacturers Alliance,

Colleagues and Partners,

On behalf of the World Health Organization, I extend my warmest congratulations to Egypt for becoming the first country in the Eastern Mediterranean Region to achieve the regional target for hepatitis B control, as set by the Regional Committee Resolution EM/RC56/R.5 (2009).

This recognition follows a rigorous review led by the independent Regional Validation Committee (RVC).

Based on robust and verifiable data, the RVC concluded that Egypt has indeed met the regional target, supported by the following key indicators:

• Hepatitis B surface antigen (HBsAg) prevalence among children aged 5 years and older is below 1 per cent;
• Third-dose hepatitis B vaccine coverage maintained at 90 per cent or higher for over a decade;
• And birth dose coverage has exceeded 90 per cent for at least five years.

These achievements are a testament to your leadership, sustained investment, and steadfast commitment to public health.

I commend Your Excellency, the Ministry of Health and Population, and the dedicated teams driving Egypt’s national immunization and hepatitis control programmes.

Egypt’s success represents not only a national achievement, but a regional milestone—a powerful example of what is possible when science, policy, and public trust align.

Through your strong Expanded Programme on Immunization, you have significantly reduced vaccine-preventable diseases, improved child survival, and strengthened health systems—culminating in the elimination of measles and rubella.

WHO stands ready to support you in introducing additional life-saving vaccines to protect against rotavirus, human papillomavirus, pneumococcus bacteria, and other deadly pathogens.

Moreover, the establishment of the Egyptian Vaccine Manufacturers Alliance (EVMA) signifies a bold step toward self-reliance, vaccine innovation, and equitable access. This is crucial for sustaining high coverage and ensuring timely, affordable vaccines for all.

But this success is not the end—it is a beginning. With continued commitment, Egypt is well-positioned to move from control to elimination of hepatitis B as a public health threat.

I urge other countries in the Eastern Mediterranean Region to draw inspiration from Egypt’s journey. With determined leadership, evidence-based strategies, and inclusive partnerships, we can achieve similar milestones.

Once again, congratulations Egypt.

Tracking measles through wastewater is giving health officials a new window into where the virus is spreading.

The United States has, for 70 years, been fighting a continuous aerial war against the New World screwworm, a parasite that eats animals alive: cow, pig, deer, dog, even human. (Its scientific name, C. hominivorax, translates to “man-eater.”) Larvae of the parasitic fly chew through flesh, transforming small nicks into big, gruesome wounds. But in the 1950s, the U.S. Department of Agriculture laid the groundwork for a continent-wide assault. Workers raised screwworms in factories, blasted them with radiation until they were sterile, and dropped the sterile adult screwworms by the millions—even hundreds of millions—weekly over the U.S., then farther south in Mexico, and eventually in the rest of North America.

The sterile flies proceeded to, well, screw the continent’s wild populations into oblivion, and in 2006, an invisible barrier was established at the Darién Gap, the jungle that straddles the Panama-Colombia border, to cordon the screwworm-free north off from the south. The barrier, as I observed when I reported from Panama several years ago, consisted of planes releasing millions of sterile screwworms to rain down over the Darién Gap every week. This never-ending battle kept the threat of screwworms far from America.

But in 2022, the barrier was breached. Cases in Panama—mostly in cattle—skyrocketed from dozens a year to 1,000, despite ongoing drops of sterile flies. The parasite then began moving northward, at first slowly and then rapidly by 2024, which is when I began getting alarmed emails from those following the situation in Central America. As of this month, the parasite has advanced 1,600 miles through eight countries to reach Oaxaca and Veracruz in Mexico, with 700 miles left to go until the Texas border. The U.S. subsequently suspended live-cattle imports from Mexico.

Central America is shaped like a funnel with a long, bumpy tail that reaches its skinniest point in Panama. Back in the day, the USDA helped pay for screwworm eradication down to Panama out of not pure altruism but economic pragmatism: Establishing a 100-mile screwworm barrier there is cheaper than creating one at the 2,000-mile U.S.-Mexico border. Even after screwworms began creeping up the tail of the funnel recently, the anti-screwworm campaign had one last good chance of stopping them at a narrow isthmus in southern Mexico—after which the funnel grows dramatically wider. It failed. The latest screwworm detections in Oaxaca and Veracruz are just beyond the isthmus.

Online Angus Reid survey comes as measles cases continue to climb across Canada