So a dirty bomb just went off in your fair 
city and contaminated a few blocks with radioactivity. Do you just put up a barrier and keep people out for a few decades until radiation fades away? Or maybe tear the whole neighborhood down.
Maybe not. In an AAAS seminar about dirty bombs, a researcher said scientists are developing a cleaning agent called a "superabsorbing gel" to remove radioactivity from materials like concrete.
Workers could spray the agent on buildings and then remove it -- along with the radioactive material -- with only a wet vacuum.
More details are here.
