Iowa Senator Chuck Grassley says he’s having to cancel today’s meetings with everyone from the Budget Committee to the Mason City Chamber of Commerce. The discovery of what may be a killer powder yesterday in the Senate Majority leader’s office has forced the closing of three Senate office buildings. Grassley says everything has to be rescheduled, including meetings today with the presidents of Iowa’s private colleges and the leaders of the Iowa Postmasters League.The Senate -is- in session today. U.S. Capitol police say two of three early tests indicated the substance was ricin (ry’-sin), however, a third test was negative. A fourth, more definitive test was being conducted but the results aren’t expected until later today. Sixteen people who may’ve been exposed were decontaminated and allowed to go home. Grassley says any Iowans who are trying to contact him in writing should use e-mail or wait until the situation’s resolved. He says all of the mail will be taken out of the capitol and people should not expect a response anytime soon. Based on what happened after terrorist attacks in 2001, Grassley says it’s possible the mail from the past few days will -never- be read, so he recommends Iowans -not- write to him while the ricin scare is still being sorted out. Grassley says “If they need something that’s real important, it may just be lost in some big black hole here.” He says most of the mail that arrived between mid-October of 2001 and the end of that year was disposed of by capitol authorities as a precaution against anthrax. Ricin is said to be twice as lethal as cobra venom.