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 Sydney Harbour Bridge, also affectionately known as the 'Coathanger', was opened on March 19th 1932 by Premier Jack Lang, after six years of construction. Made of steel the bridge contains 6 million hand driven rivets. The surface area that requires painting is equal to about the surface area of 60 sports fields.