Volatile chemical contamination can last in burn areas long after urban wildfires

Air pollution in war-torn Iran unleashes invisible toxic threats

Burning oil depots and bombed buildings are endangering the health of millions of people during the 2026 attacks. Heavy metals from munitions and other damaged materials are going airborne, but the exact health implications depends on dose, wind currents, and other factors including preexisting health conditions.

Los Angeles once suffered some of the worst smog on Earth

From the 1940s through the 1960s, Los Angeles was blanketed by dense, eye-burning smog so severe that drivers sometimes couldn't see traffic lights. The issue led to the nation's first local air pollution controls and inspired the passage of the 1970 Clean Air Act.

Urushiol, the oily toxin in poison ivy, can remain allergenic on clothing for years.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

Tornadoes can cause significant air pollution and diminish air quality

Asbestos, a hazardous material that can cause lung cancer, is commonly found in buildings constructed before 1980. Tornadoes that damage such buildings can release asbestos into the air, along with other toxic pollutants and dust as materials are lifted. Individuals, particularly those with asthma or other chronic lung diseases, are encouraged to wear masks after a tornado.

A third of Americans now live in wildfire risk zones

Climate change and human development into fire-prone regions have extended the wildfire season, with some areas experiencing fire conditions year-round. Extreme conditions, poor compensation, and exposure to carcinogens have complicated firefighter recruitment, further exacerbating wildfire risks.

Explore how close you live to some of the most contaminated places in the US

Known as Superfund sites, these toxic locations undergo long-term cleanup to remove hazardous waste, protect health, and restore land for safe reuse. As of 2025, the EPA lists around 1,300 active Superfund sites on its National Priorities List, with more than 450 cleaned and removed since 1980.

Beyond burns, fireworks can harm respiratory, auditory, and visual health

While mishandling fireworks can cause severe burns and loss of appendages, there are also risks for viewers of displays. Released particulate matter can cause the surrounding air to resemble wildfire smoke, and the explosions can cause hearing loss and damage to the corneas.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

Some faucets in regions near fracking wells run flammable water

A 2011 study found methane contamination as much as 3,000 feet away from wells, although there was no evidence of fracking chemicals in tested wells. Water with low methane concentrations is not harmful to drink, but it becomes flammable when mixed with air.

Urushiol, the oily toxin in poison ivy, can remain allergenic on clothing for years

The substance can still cause rashes even after being on shoelaces, clothing, sleeping bags, boots, or other clothing for multiple years—some reports say five years on surfaces—so they all need to be washed after outdoor adventures with the plants.

'Last Week Tonight' explores the risks of forever chemicals (warning: language)

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals used in a wide range of products due to their unique properties. However, because they can persist in the body and environment for thousands of years, they’ve earned the moniker “forever chemicals”—and have been linked with numerous health risks.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

Volcanic ash is composed of fragments of volcanic rock, minerals, and glass

These abrasive particles are hazardous to aircraft. They can melt within engines and re-solidify on turbine blades, preventing forward propulsion. If inhaled, chemicals within ash can be toxic, and the particles can embed themselves into the lungs' ducts, causing suffocation.

Spontaneous combustion involves an object igniting on its own

Even without matches, sparks, or external flames, exothermic chemical or biological reactions can increase the internal temperature of objects to the point where they reach a threshold temperature that can cause them to catch fire. Running batteries and fermenting bacteria within compressed materials can build this heat and cause combustion.

Where radon comes from and why it may be the most dangerous source of radioactivity

Released from underground bedrock before passing through soil, this radioactive gas is produced from the decay of uranium, thorium, and radium and accounts for about half of all human exposure to radiation. It is the leading cause of lung cancer among nonsmokers and can build up in enclosed spaces such as buildings without proper ventilation to dilute the gas.

The surprising world of coal seam fires

Hundreds of coal seam fires are actively smoldering around the world at any given time, including some that have stayed lit for centuries. These fires have occurred naturally for millions of years, lit atop deposits of coal in the earth. Dive into...

What the research says about the link between lead pollution and crime

The lead-crime hypothesis links childhood lead exposure to impulsivity and aggression as an adult, traits typically associated with higher crime risk. A 2022 meta-analysis found that reducing lead may explain up to 28% of the US homicide decline, but not the broader crime drop.

A flood left 2023 Burning Man attendees stuck in the desert

During Burning Man 2023, unexpected heavy rainfall and road closures in the desert led to thousands of attendees becoming trapped in the mud with limited resources. The parties and rituals prevailed, but burners also suffered serious consequences with injuries, lost and damaged supplies, and one death.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Cigarette smoke exposure boosts MS risk by up to 55%, though smokeless tobacco doesn't

The components of the smoke itself are associated with these significantly increased risks, so it's something beyond nicotine itself that drives that risk. What's more, smoking also increases the risk of developing antibodies to MS-treating drugs.

Tattoo inks are largely unregulated by the FDA

With hundreds of ink manufacturers, all unregulated by the FDA, it’s hard to determine the exact ingredients in tattoo inks. Some pigments may contain carcinogenic chemicals, such as heavy metals and aromatic hydrocarbons, or even bacterial contaminants. Red ink often causes allergic reactions and may even contain lead or mercury.

Is Agent Orange still causing birth defects?

Though the dangerous nature of the chemical is clear, its impact across generations is less so. How far down the bloodline does Agent Orange travel, and what does it leave in its wake, if anything? This Scientific American article examines why there’s debate about Agent Orange’s legacy.

Excluding water vapor, greenhouse gases make up less than 1% of Earth's atmosphere

Although carbon dioxide, methane, nitrous oxide, ozone, and most fluorinated gases account for only a minority of the planet's greenhouse effect due to their lower concentrations, they are more effective at trapping thermal radiation. While water vapor condenses within two weeks, other greenhouse gases linger in the atmosphere for years on average.

Post-treatment Lyme disease syndrome may be caused by bacterial remnants in the liver

PTLDS, which refers to lingering symptoms of Lyme after antibiotic treatment, is an area of active research. Rodent research published in 2025 suggests that these ongoing symptoms may potentially be due to the body's inflammatory response to lingering cellular components from the bacteria that cause Lyme, Borrelia burgdorferi. In rodents, components of the bacteria's cellular wall may remain in the liver after the bacteria were eliminated with antibiotics.

Acrylamide forms naturally during high-heat cooking through the Maillard reaction

While studies have shown it can damage DNA and potentially cause cancer in mice, humans absorb and metabolize acrylamide at different rates, introducing uncertainty in the research's applicability to humans. Some international health agencies have nonetheless recommended avoiding darker roasts when cooking starchy foods.

Marie Curie's work with radioactive materials left traces on her furniture and notes

Some of Marie Curie's family heirlooms were radioactive and destroyed. Marie and Pierre Curie are entombed in lead coffins to block radiation.

Dogs smell a lot of stuff we can't, including bed bugs and chemicals in electronic devices

In addition to identifying medical smells and tiny insects like bed bugs, dogs can also detect electronic storage devices. These tools often contain triphenylphosphine oxide, a chemical used to prevent overheating.

Measles is one of the most contagious preventable diseases

The virus’s ability to persist in the air for up to two hours means an infected person could enter a room, leave, and two hours later infect someone else entering the room. Its location in the body’s upper respiratory tract also makes it easy for viral particles to be sneezed or coughed into the air.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Tattoos remain visible on your skin thanks to immune cells called macrophages

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

Cultural norms about how to handle the bodies of loved ones in communities in West Africa have hampered Ebola responses.

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

In 2009, the nation was gripped by the story of a missing young boy who was believed to be floating over Colorado in a homemade balloon, until it was revealed that he was at home the whole time.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.