The culprit is a molecule called gliadin, which is found in certain gluten-containing grains and causes symptoms in gluten-sensitive people. The grains that cause the greatest problems are wheat, rye, barley, spelt, and kamut; whereas corn, rice, millet, and buckwheat are generally considered safe.
The Forth Bridge's piers are constructed from 120,000 cubic yards of concrete and masonry, faced with 2 ft thick granite. 200 trains use the bridge every day, carrying 3 million passengers each year. The total painted area of the Forth Bridge is 230,000 sq metres, requiring 240,000 litres of paint.
The Forth Bridge is a cantilever railway bridge across the Firth of Forth in the east of Scotland, 9 miles (14 kilometres) west of Edinburgh City Centre. It is considered an iconic structure and a symbol of Scotland (having been voted Scotland's greatest man-made wonder in 2016), and is a UNESCO World Heritage Site.