Induced radioactivity is the ability to manipulate the movement of subatomic particles, thus generating and emitting toxic radiation.
- Ted Sprague was the first character in normal continuity to have this ability.
- Peter Petrelli absorbed this ability from Ted, but lost it when his father stole his powers.
- Sylar stole this ability from Ted, but lost it after being infected by the Shanti virus.
- In a possible future, Gabriel Gray has somehow regained this ability.
Ted had limited control over his ability to emit radiation. When agitated, he appeared to emit radiation unintentionally. This radiation was harmful to people in this vicinity. His control did improve with practice, and he appeared to be able to emit radiation on purpose, but he apparently couldn't consistently prevent himself from emitting radiation, especially if angry or injured.
Ted could apparently emit a broad spectrum of electromagnetic radiation, although he had only a limited understanding of the physics involved. He could not choose specifically whether to emit microwaves or gamma rays, but he could choose whether to radiate "hot" energy or "bright" energy. He also appeared to be able to emit neutron radiation, as some objects that have been exposed to him have become radioactive.
At close range, Ted could produce enough radiation to bring a glass of water to a boil or melt a brass door lock in just a few seconds. His uncontrolled emissions set fire to common construction materials from several meters away. He was also capable of emitting an electromagnetic pulse strong enough to disable electronics throughout a large building. An uncontrolled release of radiation can generate a massive explosion similar to that of a nuclear bomb. In an alternate timeline, such an explosion occurred in Kirby Plaza and was powerful enough to destroy most of the skyscrapers in Midtown Manhattan.
Ted appeared to be unharmed by his own radioactive emissions. He caused the deaths of others (reducing people to skeletal remains) during at least two escapes, but never appeared to affect hismelf. Whether this immunity applies to radiation from other sources is unknown. Additionally, the Company believed that clonazepam could act as a tranquilizer for Ted. However, despite being injected with it, he still blew up the Bennets' home in a massive explosion.
When he absorbed this ability from Ted Sprague in The Hard Part after meeting him at Kirby Plaza, he had to intesnely concentrate to get this power under control. In How to Stop an Exploding Man, he even passed out attempting to do so. During his fight with Sylar, he lost control and was on the verge of exploding, but thanks to Nathan, he was flown high enough to explode without causing any significant damage to anyone other than Nathan who suffered severe radiation burns.
Since then, he has shown greater control over this ability. After four months of not using it, he used it to safely incinerate Strain 138 without losing control or exploding.
Later, Peter lost this ability when Arthur Petrelli stole his powers.
After taking this ability from Ted, Sylar stands on the roof of a building, conjuring up radiation on command. Sylar has never been seen emitting radiation unintentionally and conjured plumes of smoke shortly after acquiring the ability, whereas Ted took an extended period of time to do the same.
Gabriel becomes enraged after his son is killed by Knox. He channels this ability through his hands when he punches Knox. He begins to lose control of the ability, however, and soon explodes, destroying Costa Verde.
- Amid Halebi has this ability.
- While Ted, Peter, and Sylar have never been harmed by their own radiation emissions, Amid's hands had visible radiation damage, as seen in the scene in the unaired pilot.