An extensive investigation by the Reuters news agency has found that many children living on U.S. military bases may be exposed to hazardous levels of lead in decaying family housing. The investigation included tests done at Columbia University’s Lamont-Doherty Earth Observatory on samples of water, soil, and paint, from homes on seven bases. As a result of the report, a bipartisan group of four U.S. senators, in part citing the tests, has asked the Army for its own report on the problem, and immediate strategies to address it.