In a city with a rich history like Chicago's, you can often be surprised what lies beneath your feet. Rip up some concrete to redo a curb or fix a pothole and you might find remnant's of Chicago's earlier brick-paved streets or even abandoned streetcar tracks. But if you're not careful where you dig, you might find yourself breathing in a cloud of radioactive thorium. Before people fully understood radioactivity, a company called Lindsay Light Co. churned out unknown tons of thorium-laced sand in the process of making wicks for the city's gas lanterns and that sand was given away to builders who used it to set foundations in the Streeterville and the Near East Side, the Tribune reports.
However, there's no danger as long as there remains several generations' worth of dirt and development between you and the radioactive refuse. But for construction workers digging in those areas, nearly every scoop of ground needs to be scanned for radiation before it can be handled. This has already affected the construction of the Loews Hotel and the residential tower at 455 N. Park Drive. Thanks to a huge financial settlement between the US Justice Department and the company that now owns Lindsay Light Co's liability, the city now has $121 million to use towards the ongoing cleanup.
This post was authored by Curbed Chicago contributor Aaron Dunlap
· Gaslight era left radioactive legacy in Chicago [Tribune]