CHICAGO - JULY 28: A crane is working on a new condo under construction, amongst other residential and commercial buildings July 28, 2006 in the new "Eastside" area of Chicago, Illinois. The Chicago area, especially in the downtown and near-downtown area is booming of late with new condominium construction. According to some developers, Chicago has upwards of 12,500 condominium units either under construction or in the design/proposal stage. Reportedly in 2005 the city had condo sales of just over 8,100 and the year previous just under 6,300. (Photo by Tim Boyle/Getty Images)
Construction sites in Cook County are about to get greener.
County Board President Todd Stroger signed an ordinance Thursday that will cut diesel pollution from construction equipment.
Contractors must immediately begin using ultra low-sulphur fuel. Then they must install filters to cut emissions 50 percent by 2011 and 90 percent by 2014.
Diesel emissions include tiny particles that can lodge deep in the lungs and cause respiratory and heart problems. It's also suspected of causing cancer.
The Respiratory Health Association of Metropolitan Chicago says diesel soot causes about 755 deaths, 1,000 heart attacks 17,000 asthma attacks in the area annually. State data show construction equipment is one of the biggest sources of diesel soot.