World War I ended nearly 100 years ago, but in some places along what used to be the Western Front, in France and Belgium and near the Swiss border, the shadow of death and danger cast by that war lives on. It's estimated that for every square meter in the vast battlefields around Verdun, France, a ton of explosive shells were dropped. One in four failed to go off. Many of those are still in the ground today, despite decades of work by bomb removal workers -- more than 600 of whom have died trying to clear the fields in France alone since 1945 -- and they are still dangerous. Some are live, and even more potentially deadly than when first dropped, and many others are poisonous, leaching toxic yellow sludge into the ground and posing health hazards to any who might touch them -- as hapless tourists on old battlefields sometimes do. (Not to mention vast caches of dumped mustard gas, in forests and in the ocean not far from public beaches, five grams of which can kill an adult via skin contact.)
The Iron Harvest is what Belgian and French farmers reap when they plow their fields along what used to be the Western Front. Every year, they find tons of unexploded ordnance, barbed wire, shrapnel, bullets, and trench supports. And because this was trench warfare, often fought in swampy conditions, much of the unexploded bombs worked their way down deep into the muck and were encased there, meaning no matter how hard the bomb removal crews work, sometimes the only things that can unearth the bombs are time and a farmer's plow. When they recover these objects, farmers simply leave them on the edges of their fields to be collected and disposed of by the authorities. Above: the iron harvest of a French farmer in the Somme (picture by Battlefields.co.uk).
A particularly productive "harvest" can yield stacks of bombs or mustard gas canisters as tall as a house. This iron harvest photo by flickr user Salfordian gives you a sense of how much one field can turn up -- and how unimaginably hellish these now verdant and peaceful-looking fields must once have been.
Of course, there are "iron harvests" in former battlefields all over the world, not just France and Belgium. Southeast Asia is littered with unexploded ordnance -- the US dropped more bombs on Vietnam than were dropped during all of WWII. The citizens of Okinawa -- known by some military folk as "Bomb Island" -- are routinely evacuated so newly-discovered bombs can be cleared from urban areas and beaches. A German highway worker was recently killed when he hit a bomb while making repairs to a section of the Autobahn. More than 100 Afghan civilians -- most of them children and farmers -- are killed or wounded every month from mines and unexploded bombs, many dating back to the 80s.
Even in the United States, according to the EPA, there are unexploded bombs "at 16,000 domestic inactive military ranges within the United States that pose an 'imminent and substantial' public health risk and could require the largest environmental cleanup ever, at a cost of at least US$14 billion. Some individual ranges cover 500 square miles (1,300 km2), and, taken together, the ranges comprise an area the size of Florida." Which is to say, one of these days we may have our own iron harvest.