As per the World Health Organization, all but 1% of the world's population is exposed to unhealthy air and also exceeds the WHO limits for pollutants. However, there are some parts of the world where aur quality has improved through policies that limits pollution, while in other parts, it has not reached the desired results.

For US, more than 25% of the population is exposed to "unhealthy" air as per the Environmental Protection Agency (EPA), this is according to the report by the climate non-profit First Street Foundation. By 2050, the number of people exposed to "unhealthy" air will increase by more than half. The worst days of air pollution, reports BBC, "hazardous" or maroon under the EPA's system will rise by 27%.

Why are we talking about this today? It is because of the recent wildfire in California, which started on January 7. This is also one of the factors that is spiking the PM2.5 levels. It has increased by up to five micrograms per cubic metre in the western US in the past decade.

What is PM2.5?

It is a type of air pollution which is made of particulate matter and measures 2.5 micrometres across or less. It is roughly 30 times smaller than the width of a human hair. These particles are made with a mixture of solid and liquid substances, which varies in their chemical composition, including carbon, metals, and organic compounds.

These specks of airborne soot, dust and other substances can also trigger inflammation, which could also damage your brain.

As per a 2021 study titled The Changing risk and burden of wildfire in the United States, a quarter of US's PM2.5 pollution was caused by wildfire smoke. In 2023, US also witnessed a significant dip in air quality and visibility as smoke from wildfires north of the Canadian border entered across the continent. In May 2024, Canada also saw a start to its wildfire season, and one town was evacuated in British Colombia.

Wildfire smoke and its effects

Wildfires do not only affect those who live near forests, peatlands, and grasslands, but also to the cities and environment in general. It can send plumes up to 14 miles or 23km into the stratosphere, and from there, it can spread all over the globe. For instance, in 2023, the Siberian wildfires released smoke that travelled across the Pacific Oceans to reach Alaska and Seattle.

Other than PM2.5, wildfire smoke is also harmful to immune cells in lungs, and the toxicity could be four times greater than particulates from other types of pollution.

Another 2019 study titled Effects of Atmosphere Processing on the Oxidative Potential of Biomass Burning Organic Aerosols found the toxicity of smoke doubled in the hours after it was first emitted and reached four times greater toxicity at its peak.

Health Impact

There have been research that shows how pollution affects your brain. It can lead to impaired judgment, poorer performance in school and even higher levels of crime, as per the 2018 study by the London School of Economics.

Other health concerns include weight gain. There have been researches that links airborne pollution such as PM2.5 to obesity. The studies have found that children who live in most polluted areas are twice as more likely to have obesity. Some studies also find the link of air pollution harming our sense of smell. As per an Italian study from 2022, titled Association between environmental air pollution and olfactory functioning among Italian adolescents and young adults in Northern Italy, noses of teenagers and young adults became less sensitive to odors after being exposed to nitrogen dioxide, which is a component in traffic fumes.

A two-year-old boy from Bristol, UK has died from a rare heart disease, known to mostly affect children with only flu-like symptoms, on January 8.

Hudson Martin had been diagnosed with Kawasaki disease when he was seven months old and was placed on lifelong medication including aspirin and blood thinners to reduce the risk of clots. Since then, he had been living a normal and happy life, according to father Damien Martin.

He told Bristol Live: "You’d never know anything was wrong from pictures or videos. He bounced off everything. He loved climbing, dancing, music, he was a proper daredevil."

But days before his third birthday, he suddenly collapsed while playing at home. Despite being given CPR by paramedics for an hour, his heart did not restart and he passed away.

“They did absolutely everything they could,” Damien said. "His heart just wouldn't come back."

What Is Kawasaki Disease?

Also known as mucocutaneous lymph node syndrome, Kawasaki disease causes inflammation in the walls of small to medium-sized blood vessels that carry blood throughout the body which can damage to the heart and blood vessels, mostly in children younger than five years old.

When this happens, the heart doesn't work as well to pump blood to the body and could burst (coronary artery dilation and aneurysms). It also causes swelling in the lymph nodes and mucous membranes inside the mouth, nose, eyes and throat.

Apart from a 102.2 degrees Fahrenheit (39 degrees Celsius) fever that can last for five days, children with Kawasaki may also experience some or all of the following symptoms:

• Rash on the main part of the body or in the genital area
• Swelling and redness of their hands and feet
• Irritation and redness of the whites of their eyes
• Swollen lymph glands in the neck
• Irritation and inflammation of the mouth, lips, and throat

It remains unknown what causes Kawasaki disease in children and if it affects adults.

Diagnosis involves ruling out other diseases that cause the same symptoms which include:

• Scarlet fever
• Juvenile rheumatoid arthritis
• Stevens-Johnson syndrome (a disorder of the mucous membranes)
• Toxic shock syndrome
• Measles
• Some illnesses caused by ticks, such as Rocky Mountain spotted fever

Is It Curable?

While this non-contagious disease can be treated with a mixture of antibodies given through the veins (intravenous immunoglobulin) and aspirin, it remains uncurable. Doctors may also advice steroids if intravenous immunoglobulin is not effective.

After receiving treatment for Kawasaki disease, most children recover fully and long-term follow-up care remains unnecessary. However, children who have suffered through aneurysms or other complications related to the disease will need lifelong monitoring with a cardiologist.

Cases of scabies, a highly contagious skin condition caused by microscopic mites, continue to remain higher than normal across England this winter, according to the latest surveillance data. Recent findings from the Royal College of General Practitioners’ Research and Surveillance Centre indicate that scabies has been spreading more widely than expected over the past few months, with infections steadily increasing through autumn and winter.

Overall, reported cases have stayed above the usual five-year average, with the sharpest rise recorded during the final four months of last year, particularly across northern regions of the country. With scabies infections continuing to climb, concerns are growing around which treatments are safe to use, especially when it comes to children.

What Is Scabies?

Scabies is caused by a microscopic parasite known as Sarcoptes scabiei. This mite burrows into the top layer of the skin to lay its eggs, triggering severe itching and a red, spotty rash that often becomes more intense at night. Although the mites are too small to be seen easily, measuring less than half a millimetre, the body reacts to their saliva, eggs, and waste, leading to an allergic response.

Scabies spreads through prolonged skin-to-skin contact and can affect people of all ages. According to the NHS, it is most commonly transmitted through close household contact, including between partners, family members, people living together, and during sexual activity.

How Is Scabies Spreading In The UK?

UK Health Security Agency surveillance data shows that scabies cases reported through sexual health services remained relatively stable before the COVID-19 pandemic, but numbers began rising sharply from 2022 onwards. Diagnoses increased from 3,393 cases in 2023 to 4,872 cases in 2024, marking a 44 per cent rise.

• London accounted for roughly one-third of all cases recorded in 2024.
• The steepest percentage increase was seen in the North East, where reported cases nearly doubled.
• Young adults aged 20 to 24 made up 41 per cent of diagnoses, while those aged 25 to 34 accounted for 31 per cent.

Scabies UK: What's Behind The Surge In Cases?

Both the UKHSA and the British Association for Sexual Health and HIV (BASHH) suggest several reasons could be driving the surge:

• Increased social interaction and physical contact following the pandemic, after years of reduced mixing.
• Greater awareness of scabies and more testing taking place at sexual health clinics.
• Overcrowded housing and the ongoing cost of living crisis, which may delay access to prompt treatment.

Experts also caution that the actual number of cases is likely much higher, as the available data only reflects diagnoses made in sexual health settings.

Scabies UK: Can Ivermectin Treat Scabies In Children Safely?

Ivermectin is an oral antiparasitic medicine used to treat scabies by paralysing the mites. It offers a systemic alternative to topical creams and is often considered in cases that are widespread, severe, or involve institutional outbreaks. Because the drug does not kill scabies eggs, a second dose is usually required after seven to fourteen days to target newly hatched mites.

According to the Centres for Disease Control and Prevention, ivermectin is generally well tolerated, improves treatment compliance compared to creams, and has been widely used in mass drug administration programmes, though repeat dosing is important due to its limited effect on mite eggs.

Despite its broad use in programmes targeting conditions such as river blindness, intestinal worms, and scabies, ivermectin has traditionally not been recommended for children weighing under 15 kilograms, largely due to limited safety data. However, researchers revisited this concern following a systematic review and meta-analysis that suggested the drug could be safe even in children weighing as little as 11 pounds.

In a double-blind clinical trial, researchers assessed the safety, effectiveness, and pharmacokinetics of ivermectin in young children with scabies. A total of 240 children weighing between 11 pounds and under 33 pounds in The Gambia, Kenya, and Brazil were randomly assigned to receive ivermectin at doses of 200, 400, or 800 micrograms per kilogram alongside a placebo cream, or placebo tablets alongside permethrin cream. Blood samples were collected on days 0, 3, 7, 10, and 14 to monitor biochemical markers, drug levels, and blood health.

Ivermectin: Only One Serious Adverse Event

The findings showed that ivermectin was effective in treating scabies, with just one serious adverse event reported. This involved a temporary increase in liver enzymes, which returned to normal levels within 32 days. All other side effects possibly linked to the treatment were mild, resolved on their own, and were similar to those seen in children weighing more than 33 pounds.

“Outcomes from the Ivermectin Safety in Small Children trial will hopefully provide greater reassurance that ivermectin can be safely used in children weighing less than 15 kilograms,” said lead study author Kevin Kobylinski, PhD, an honorary visiting research fellow at the University of Oxford with the Mahidol Oxford Tropical Medicine Research Unit in Bangkok, in an ASTMH press release.

What Is TB And What Makes It Unique From Other Diseases?

Historically too, TB was one of the deadliest diseases, which killed 1 in 7 people in the US and in Europe in the late 1800s. However, with the development of antibiotics and strong public health efforts, cases have declined significantly over the 20th century. However this is for the second year in a row that TB cases have increased in the US. The number has reached their highest levels in over a decade.

According to preliminary data from the Centers for Disease Control and Prevention (CDC), more than 10,300 cases were reported in 2023—an 8% increase from the previous year. This marks the highest number of TB cases since 2011.

Both the total number of cases and the infection rate have gone up, with 34 states reporting an increase. The rise has been observed across all age groups.

Tuberculosis (TB) is a bacterial infection that primarily affects the lungs but can spread to other parts of the body. It is transmitted through the air when an infected person coughs or sneezes. Without proper treatment, TB can be fatal.

Unique Symptoms Of TB

While TB symptoms depend on the affected area, the most unique symptom is a persistent cough, which lasts more than 3 weeks. This could also be mixed with mucus and or blood, along with chest pain, night sweats, unexplained weight loss, fever, fatigue and even appetite loss.

Extrapulmonary TB could also lead to swollen glands like neck, severe back pain in the spine, and headaches, confusion, or even blood in urine. A person with active TB may experience symptoms including: a severe cough that lasts 3 or more weeks.

John Green On Tuberculosis

What makes TB unique is how it has shaped civilization, as noted The Fault in Our Stars writer John Green. His book, Everything is Tuberculosis: The History And Persistence of Our Deadliest Infection.

The book is also inspired by a young person's battle with disease, who Green had met in Sierra Leone.

He shares, "I met Henry [Reider] at a tuberculosis hospital in Sierra Leone, a boy who had been living with multidrug-resistant tuberculosis. I thought he was 9 years old, the same age as my son, Henry.”

Read: John Green’s ‘Everything Is Tuberculosis’ Explores The Disease’s Stigma And Strange Romanticization

However it turned out that the boy was not 9. He was 17. "He'd just been so stunted by malnutrition and by tuberculosis that he looked much younger.”

Reider took Green around the hospital, and as he charmed him with his way, Green could not help but notice that the disease is eating him alive. "He was already on the last line of available antibiotics," said Green. "As one doctor put it, that is the point where you put the stethoscope down here - there was very little that was believed could be done for Henry."

However, over the years, he gained access to treatments common in wealthy countries and Green stayed in touch. He slowly got invested with the diseases and the injustices that had happened. He in fact explored origin stories and found that TB led to mass migrations to Western states, underpinned the creation of Stetson hat and spurred the assassins that kicked off the World War I.

Green also mentioned that there is such an extent of the inequity that it almost gets really hard to imagine. " But since tuberculosis became curable in the mid-1950s, we have allowed over 150 million people to die of the disease. It's one of the great marks of shame in human history, I think. I had no idea about that. I had no idea that tuberculosis was even still a thing. I thought of it very much as that disease of British romantic poets. But then I met Henry at a tuberculosis hospital in Sierra Leone, a boy who had been living with multidrug-resistant tuberculosis," he said.

He also highlighted how TB patients were treated as "special souls". This disease soon became a sign of creativity and sensitivity. However, he rightly wrote that "romanticization is not a kind or generous way of treating the ill".