Misleading measurements and fear-based reporting often exaggerate radiation risks

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.

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.

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 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.

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.

Limited transparency soon after Chernobyl made it a source of conspiracy theories

Some rumors about the event became perceived as more reliable than the Soviet mass media, which had omitted key information during the early days of uncertainty. The resulting theories included CIA involvement in the disaster, three-headed birds, aliens, and a weaponized earthquake.

Distinguishing between natural and artificial, or induced, radioactivity

Naturally occurring radioactivity comes from radioactive elements underground, cosmic radiation from the sun and other objects in space, and radioactive atoms that make up the molecules we breathe, eat, and drink. Artificial radioactivity is predominantly generated for medical applications and industrial activities.

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.

Over a lifetime, the average American's nuclear power usage creates a hockey puck of nuclear waste

Spent nuclear fuel remains hot and highly radioactive for long periods, requiring submersion in cooling pools before being stored in dry casks and deep underground repositories. The potential recycling of nuclear waste is impeded by security concerns and dangerous reprocessing methods, particularly when obtaining fresh uranium is often easier.

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.

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,...

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.

Why bananas are in trouble

The average American eats over 25 pounds of bananas every year, but we won't for long if a deadly soil fungus continues to spread. Learn what scientists are doing to save the popular fruit.

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.

Cold War nuclear tests exposed thousands to atomic blasts

After World War II, nuclear powers conducted thousands of weapons tests. This video pairs archival footage with interviews of veterans who witnessed Pacific test explosions, capturing the scale, shock, and human experience of being near a nuclear detonation.

The Curies developed a way to measure radioactivity in an old medical dissecting room

Despite lacking proper laboratory conditions, Marie and Pierre built an ionization chamber and a piezoelectric quartz electrometer to measure the amount of charged particles released by radiation, with a sensitivity of ten-trillionth of an ampere. Substances with different emission rates indicated different elements.

Mining of rare earth elements risks leaking radioactive wastewater

The extraction and processing of REEs requires significant amounts of water, and poorly regulated projects can contaminate groundwater with acids and heavy metals. Toxic waste spills have paused work in several US mines since the 1980s, despite growing REE demand.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

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.

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.

Natural toxins produced on plants or consumed by animals may cause food poisoning

When humans eat plants with certain natural toxins on them—including a family of toxins called aflatoxins that fungi produce on crops like peanuts and corn— they can become ill with food poisoning. Toxins can still harm humans even if animals or plants appear fine to the human eye. The World Health Organization advises that we should throw away moldy or discolored foods, refrain from eating wild plants or mushrooms that aren’t definitively nonpoisonous, and remember that just because something is “natural” it’s not always safe to eat.

Microplastics are infiltrating the human body with unclear but concerning effects

Scientists have linked microplastics to immune system damage, hormone disruption, inflammatory diseases, and even cancer—yet most of their health impacts remain unknown due to limited research. Studies suggest we ingest about a credit card's worth of plastic weekly.

Supplements often have issues with impurities, toxins, and inaccurate labels

Consumer Reports' tests of more than 20 supplement powders and shakes in 2025 found that more than two-thirds of them contain unsafe levels of lead. Some contained 10 times the amount of lead that's considered acceptable to ingest in a day. The levels they found, in some cases, were even higher than when they tested the products 15 years earlier.

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.

Watch an expert's take on the rare disease hantavirus—and why it's not of great concern to the general population

This rare zoonotic disease, transmitted to humans primarily through infected rodent droppings, urine, or saliva, is rarely spread between people. The disease was of particular concern in spring 2026, when an outbreak occurred on a 150-person cruise ship, prompting a flurry of action, including contact tracing for passengers in their home countries. The disease can be fatal. But early care—primarily oxygen support—can help patients survive.

Explore the decommissioning work at the Fukushima Daiichi Nuclear Power Station

This virtual tour explores the nuclear disaster site, which resulted from a magnitude 9.1 earthquake and tsunami on March 11, 2011, and the various processes underway to remove debris, fuel, and contaminated water.

Most penicillin allergy diagnoses are wrong

A Freakonomics Radio episode investigates why so many people mistakenly believe they’re allergic to penicillin. This widespread misdiagnosis leads to costlier, less effective treatments and contributes to the growing problem of antibiotic resistance.

About 40% of cancer cases are linked to preventable risk factors

Maintaining a healthy weight, engaging in regular physical activity, and consuming a balanced diet can lower cancer risk. Research indicates that about 40% of US cancer cases are linked to preventable factors, including poor diet and inactivity. Understanding these mechanisms empowers individuals to adopt healthier lifestyles for cancer prevention.

The WHO’s guidance on 5G, radiation, and health

5G is the latest wireless mobile phone technology, first widely deployed in 2019. 5G is expected to increase performance and a wide range of new applications, including strengthening e-Health (telemedicine, remote surveillance, and telesurgery).

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

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

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.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

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

How the most famous Ebola book, The Hot Zone, which sold 3.5 million copies and was translated into 30 languages, got aspects of the disease so wrong.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

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.

Poison ivy is in the same family as mangoes, cashews, and pistachios—and they all produce oily urushiol in their raw, unprocessed state—but they are typically prepared in ways to avoid causing human discomfort.

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.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.