Symptoms of extreme radiation exposure may take hours to manifest

Exposure to ionizing radiation from nuclear accidents can damage DNA

The damage can increase the risks of cancer, cataracts, heart disease, and other illnesses based on exposure times and intensities. Contaminated food, water, air, or soil from near nuclear accidents can further prolong one's exposure.

Learn about ionizing radiation and see the most radioactive places on Earth

The average person is exposed to radiation every day, though most of it is either harmless non-ionizing radiation or ionizing radiation at doses too small to significantly affect an individual. The highest doses of ionizing radiation are received by smokers due to the radioactive polonium and radioactive lead in tobacco products.

Misleading measurements and fear-based reporting often exaggerate radiation risks

Daily exposure to radioactivity is common but occurs in low doses outside of locations near nuclear accidents like Chernobyl and Fukushima. Researchers have detected radiation in tuna, bananas, and the human body due to increasing instrumental sensitivity, not rising concentrations.

About 10% of the radiation people are exposed to each year comes from outer space, with higher percentages for those living at higher elevations or who fly often.

Symptoms of DNA loss may mimic those seen in mushroom poisoning or chemotherapy

Although no organism has ever lost all its DNA, the destroying angel mushroom contains amatoxin, which disrupts DNA transcription and is known to cause death via liver and kidney failure in three days. Doxorubicin, which tangles DNA to disrupt cellular replication, compromises a person's immune system.

Heatstroke can reprogram your DNA, putting survivors at risk of future health problems.

The Chernobyl disaster released more radioactive material than the Hiroshima bomb.

The toxic dust from 9/11 sites still claims lives decades later

In the years after 9/11, nearly 17,000 first responders enrolled in health programs have reported cancers and respiratory diseases linked to Ground Zero exposure. More have died from related illnesses than were killed on the day itself.

The Curies were buried in lead-lined coffins to contain their radioactive bodies

Their discoveries of polonium and radium involved ongoing exposure to radioactive materials before shielding technology was developed. Their notebooks, furniture, and other belongings remain radioactive today, requiring researchers to sign a waiver and wear protective clothing to access.

Items in the Curie Museum do not produce significant radioactivity today

Ionizing radiation produced by elements such as uranium, polonium, and radium can damage living things, but the trace amounts found in the museum objects that Marie Curie once touched have been largely decontaminated, with more dangerous items stored in protective, lead-lined containers.

Food poisoning can sometimes cause serious long-term health issues

Although foodborne illness can be relatively mild and cause short-term discomfort, more rarely it can also cause long-term severe health consequences, depending on your individual risk factors, the severity of your sickness, and the care you receive. Kidney failure is one serious complication associated with certain types of food poisoning. Meningitis, hepatitis, arthritis, and pancreatitis are also rare and serious foodborne illness complications. If a pregnant person gets food poisoning, it can cause health issues for the fetus.

The average cell's DNA is damaged thousands of times daily

In the case of radiation-induced distortions in a DNA strand, specialized proteins can cut out entire segments and rebuild them using the second strand as a complementary template. If both DNA strands are completely severed, proteins interlace undamaged DNA with the severed DNA and rebuild both using complementary base pairing.

Calculate your estimated yearly dose of ionizing radiation

This calculator from the EPA provides a value in millirems—the US unit for effective dose—based on a variety of exposure parameters, including the state a user lives in and travel-related sources of ionizing radiation, such as passing through screening machines.

Protecting astronauts against space radiation

Outside the protective atmosphere of Earth, astronauts are constantly bombarded by radiation, which, among other dangers, increases the risk cancer. While those of us on Earth can mitigate the effects of similar radiation by limiting exposure,...

Heatstroke—from overexertion or extreme heat—drives core body temperature to 104 degrees Fahrenheit or higher, setting off a cascade of problems in the body.

Prolonged space travel significantly impacts multiple human body systems

Astronauts can lose 20% of their muscle mass after two weeks and 10% of their bone mass after six months in space. Decreased sharpness of eyesight and changes in neural connectivity, brain structure and gut bacteria have also been observed.

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.

Lengthy incubation periods are why it's tough to link foodborne illness to specific foods.

The highly contaminated Chernobyl region suffers from reduced biodiversity

Although isolation and radiation have driven adaptations in some organisms, decades of radiation have caused ongoing harm to wildlife and vegetation, including population declines in birds and insects. Higher rates of deformities and tumors have also been seen compared with animals in surrounding regions.

Watch an American news report of the Chernobyl disaster

Americans first heard about the Chernobyl nuclear disaster two days after the event, once abnormal radiation was detected in nearby countries. This forced Soviet officials to acknowledge the catastrophe publicly for the first time a few days after it occurred.

A 36-year-old Russian physicist survived a particle accelerator beam to the head

Several safety mechanisms failed during Anatoli Bugorski's inspection of malfunctioning equipment at the U-70 synchrotron, the Soviet Union's largest particle accelerator. Despite receiving as much as 600 times the lethal dose of radiation to the brain, he has shown no intellectual damage and worked until the age of 77.

New evidence suggests the eruption's victims died as their blood boiled

While most Pompeii victims suffocated or were crushed, spectroscopic analysis of bones from a nearby town indicates something more extreme: exposure to superheated gas that instantly boiled blood and caused deadly internal trauma.

Watch what the Ebola virus does inside the body in order to spread and survive.

Why taking potassium iodide to protect against radioactivity is unlikely to be effective

Since the thyroid gland cannot distinguish between radioactive and non-radioactive iodine, taking potassium iodide pills causes the thyroid to absorb the medication, leaving it unable to take up radioactive iodine from the environment. However, while this protects the sensitive gland against the most prominent radioisotope produced in nuclear accidents, it does not protect other body parts or shield against other radioactive substances.

Chronic inflammation can cause cellular damage and could lead to cancer

Over time, this cellular defense system can inadvertently damage cells and tissues when it's in this heightened alarm mode over a prolonged period. This occurs because, when immune cells are sent somewhere without a true target, they may attack healthy cells and tissues.

Because the retina lacks pain receptors, during a solar eclipse, those watching without protective eyewear may suffer from permanent damage without realizing it.

See the incubation periods for certain food poisoning-causing organisms

Read this chart that lists common food sources of different foodborne illness-causing pathogens and typical times between exposure and symptom onset.

How spoiled meat helped uncover a bacterium that can survive the vacuum of space

When a can of ground beef and pork spoiled despite attempts to sterilize it with gamma radiation, researcher Arthur Anderson isolated the bacteria in the food and discovered Deinococcus radiodurans. The polyextremophile has since been found on the walls of nuclear reactors and overcomes radiation damage through highly optimized DNA repair mechanisms.

Transplanted organs can be rejected by the body immediately, months after transplant, or slowly over years

Organ rejection remains a huge challenge for organ transplant recipients. Rejection occurs when a recipient's immune system identifies a transplanted organ as foreign and attacks it. Recipient-donor screening processes try to match antigens to help reduce this risk.

View summaries of the most common types of radioactive decay and their associated particles

The alpha particle has the strongest ability to ionize other atoms it strikes, but it also does not travel very far before colliding with something and being absorbed. Gamma particles—high-energy photons—do not interact with matter as easily and therefore possess the greatest penetrating power, though this also makes their ionizing potential the smallest.

Between 10 million and 50 million people in the US develop rashes from poison ivy, poison sumac, and poison oak annually.

Chernobyl pushed the world to create rapid-alert systems for nuclear accidents

In the aftermath of the disaster, nations adopted new agreements requiring immediate international notification of nuclear accidents. They coordinated emergency assistance—efforts led by the International Atomic Energy Agency to prevent future disasters from being concealed when radiation emergencies occur.

View a timeline of the Chernobyl disaster

The 1986 Chernobyl meltdown, caused by a combination of poor safety design and human error, is the worst nuclear accident in history. At least three dozen people died in the direct aftermath, and experts believe thousands suffered premature cancer deaths from radiation exposure.

9/11 first responders still deal with significant mental and physical impairments.

Being struck by lightning has a mortality rate of about 10%

Near-immediate deaths are the result of electrical disruptions in the heart and nervous system, causing cardiac arrest, but severe skin burns, temporary paralysis, and blown eardrums are more common. About 74% of survivors are left with a long-term disability, which includes brain damage and changes in memory and mood.

Although they rely on radioactive elements to operate, everyday technologies such as electronic exit signs, some wristwatches, and smoke detectors are not dangerous, unless they are damaged and their radioactive material is inhaled or swallowed.

Dsup protects DNA from radiation up to 3,000 times the tolerable human dose

A key component of a tardigrade’s biochemical toolkit, the damage suppressor protein is produced and binds to DNA molecules when the animal enters its dormant tun state. Dsup has provided a 50% reduction in double-strand DNA breaks in mice after exposure to X-rays.

More extreme heat days are putting human health at risk in both the short and long term

America is generally experiencing more frequent extreme heat days, over a longer period, in certain parts of the country. The heat-related death toll is rising, and beyond those direct deaths, extreme heat can also have troubling ripple effects including elevated violence and decreased productivity.

The story of the Radium Girls, who exposed the dangers of radioactive paint

After radium was discovered in 1898, companies began using radium-based paints on watch and clock dials to create a glow-in-the-dark effect. Women who worked to apply the paint were encouraged to use their lips and tongues to help create the fine point needed to draw small numbers, unknowingly poisoning themselves.

Ebola virus, with an average fatality rate of around 50%, has been responsible for more than 2,000 confirmed deaths during the 2026 outbreak in the Democratic Republic of the Congo and Uganda.

More than 500,000 people worked to contain Chernobyl's fallout, many with very little radiation protection.

Study pinpoints where to hide during a nuclear blast

There’s no surviving the fireball of a nuclear bomb, but beyond that, there are certain spots indoors where you can try avoid the destructive shockwave.

Schizophrenia symptoms often appear suddenly

Schizophrenia is a particularly shocking mental illness because its symptoms may appear seemingly without any prior signs of illness after a person has had no symptoms for the first couple of decades of their life. Among teens, symptoms may look like typical adolescent behaviors—withdrawal, being irritable, and having trouble sleeping.

Key symptoms of burnout can be both mental and physical

Burnout can be accompanied by several symptoms, including low energy and chronic fatigue, trouble concentrating, difficulty sleeping, and depression. It may even manifest physically as musculoskeletal pain, headaches, stomach and intestinal pain, and more. More intense cases have been linked to cardiovascular and mental health disorders.

About 20% of people infected with cholera have severe symptoms

That's according to studies from outbreaks in Bangladesh. Most people who contract the disease have mild or moderate symptoms, or none at all. Yet anyone infected with the disease-causing bacteria can shed the pathogens in their feces for a few days, or even up to around 10, seeding the environment with bacteria.

The Chernobyl exclusion zone has become a unique wildlife refuge

Within the area—roughly the size of Yosemite National Park—animals such as wolves, bears, and feral dogs descended from the pets left behind have gradually adapted to low-level radiation. Eastern tree frogs in the area have darker skin than usual, which may have helped protect them from ionizing radiation.

Measles infection can cause long-term immune system “amnesia”

The measles virus attacks the body's immune system, including preying on T and B cells in the lymphatic system. These cells hold memories of past infections, which can be degraded as the virus destroys them. This leaves patients susceptible to other infections for a year or longer.

Learn how cholera bacteria sicken humans

Once a person has ingested large amounts of the bacteria, typically through contaminated water, cholera bacteria begin producing and releasing a toxin inside their host. It attacks the mucosal lining of the intestine, making it hard to absorb liquids. This process leads to cholera's characteristic symptoms, like voluminous, watery diarrhea.

Explore illustrative depictions of Chernobyl in comic books

Pieces related to the location since the nuclear disaster have told stories about radioactive vampires and monsters, accounts of bureaucratic corruption and creed, and visual retellings of experiences those in the region lived through before and after the event.

Measles attacks the body's immune system, leaving it vulnerable to secondary complications.