In Japanese schools, much of the cleaning is done by the pupils themselves: every day, during 'o-soji', they sweep, mop floors and clean corridors, sometimes even the toilets. At lunchtime, they also serve the meal to their classmates, wearing smocks and caps. Built into school life from primary school onwards, these chores are meant to teach respect for shared spaces, cooperation and responsibility.
That's the estimate from a WHO-led study published in The Lancet in 2024, covering the half-century since the Expanded Programme on Immunization was launched in 1974. It works out to about six lives saved every minute, mostly infants. The measles vaccine alone accounts for around 60% of those lives.
According to the World Gold Council, about 216,000 tonnes of gold have been mined in all of human history. Because gold is so dense (19.3 tonnes per cubic metre), it would fit in a cube about 22 metres on each side, roughly the height of a seven-storey building. Strikingly, about two-thirds of it has been mined since 1950.