Lead testing is used to determine the amount of lead in the bloodstream. It can also be used to determine if treatment of lead poisoning is working and that lead levels are decreasing. Over the past 45 years, the acceptable levels of lead in the blood have changed significantly. As more information concerning lead and its effects on the body are learned, the number that is acceptable continues to down. In 1997 the level of lead that was considered dangerous was dropped to 10 micrograms per deciliter. Lead poison test guidelines for testing children were established in 1997 and the guidelines for managing those who had elevated lead in 2002. These guidelines recommend that all children who are part of an assistance program be tested for lead along with all children known to live in apartments or housing built before 1950. Lead poisoning tests in children are initially done with a finger prick. However, if the test shows elevated lead levels, another test is ordered using venous blood. This is to make sure the original test was not contaminated during the original finger prick. If the lead poison tests are accurate, appropriate measures should be taken to counteract the lead poisoning.