A number of U.S. troops with unexplained symptoms such as impaired concentration, anger, irritability and impulsivity, as well as physical problems such as high blood pressure, peripheral neuropathy and low sex drive, have chronic lead poisoning, according to a report Wednesday in The New York Times Magazine's At War Blog. Thirty-eight troops — mostly from Special Forces units — have gone to Mount Sinai Medical Center in New York for a special test that measures the level of lead in one's tibia bone. Of those, a dozen registered bone lead levels higher than normal, with four having roughly twice the expected amount. Dozens of other service members sought treatment at the Cleveland Clinic's Center for Functional Medicine for lead and other metal poisoning, including those tested at Mount Sinai. Troops can inhale lead or ingest it by firing weapons or eating, drinking, smoking or chewing tobacco on ranges. If lead is absorbed, it is present in the bloodstream for up to a month, where it can be detected by a blood test, and it remains in soft tissue for up to 90 days. It is then absorbed into the bones, where levels can increase with additional exposure. Read more on Military.com.