Human spit build-up could cause bridge collapse

The Howrah Bridge in the Indian city of Kolkata is at risk of collapsing because the steel at its base is being corroded by human saliva.

Pedestrians who have been chewing betel leaf, areca nut and slaked lime have been spitting on the bridge’s steel hangers, causing them to weaken.

The red stains left by the paan mixture — a mild stimulant chewed throughout India — are caked around the metal casings of the bridge.

Authorities say the paan-laced spit has reduced the thickness of the bridge’s hangers from six millimetres to three millimetres — via redwolf.newsvine.com