A piece of construction equipment that contains a radioactive pellet that can be dangerous is missing in Arapahoe County.Health experts said it can be dangerous and there is a $2,500 reward for finding it.The two-foot long rod is missing on Arapahoe Road, somewhere between Havana and Potomac streets. The search has gone on for three days without success.The rod contained Cesium 137 and fell off a truck sometime Friday. It is used in gauges in the construction industry.Health experts said that from a distance of five to 10 feet, it's not much of a danger."But if you are close to it, or handle it, you're getting exposure into your hands or your body," said Steve Tarlton, with the Colorado Health Department. "It's not deadly, but its radiation you don't need and don't want to have in your body."It's thought that someone may have picked it up and thrown it in their truck and is not aware of the danger.If you think you've found the rod, don't pick it up. Call the Arapahoe County Sheriff's Office.