Context: Recently, Russia intends to raise at the United Nations Security Council its accusation that Ukraine is planning a “dirty bomb” attack.

About Dirty bombs

• Dirty bombs do not create city-flattening atomic explosion but are designed to spread toxic waste.

• The immediate health impact would probably be limited, since most people in an affected area would be able to escape before experiencing lethal doses of radiation.

• But the economic damage could be massive from having to evacuate urban areas or even abandon whole cities.

• A bomb using radioactive caesium from a misplaced or stolen medical device might require the evacuation of an area of several city blocks, making it unsafe for decades.

• A piece of radioactive cobalt from a food irradiation plant could, if blasted apart in a bomb in New York, contaminate a 380 square mile (1,000 square km) area and potentially make the island of Manhattan uninhabitable.

Is a dirty bomb a nuclear weapon?

• No. The blast from a dirty bomb is generated by conventional explosives.

• The blast from a nuclear weapon is generated by a nuclear reaction, such as the atomic bombs the US dropped on Japan in World War II.

• A nuclear bomb creates an explosion that is thousands to millions of times more powerful than any conventional explosive that might be used in a dirty bomb.

• The blast from a nuclear weapon can flatten entire cities.

• For instance, the atomic bomb dropped on Nagasaki in 1945 obliterated 2.6 square miles (6.2 square kilometers) of the city

• The conventional explosives in a dirty bomb may only flatten or damage a few buildings.

Has a dirty bomb ever been used?

• No. In 1995, Chechen rebels planted but failed to detonate one in a Moscow park.

• There have been reports that terrorist organizations such as al Qaeda or ISIS have built or tried to build a dirty bomb, but none has ever been detonated.