Children drinking tap water from the Flint River in Michigan had high levels of lead in their blood, and those levels dropped as soon as the water source was changed back to the Detroit water system, a newly published Centers for Disease Control and Prevention investigation has found. 

"This crisis was entirely preventable, and a startling reminder of the critical need to eliminate all sources of lead from our children’s environment," Patrick Breysse, director of the CDC’s National Center for Environmental Health, said in a statement Friday reporting the findings. "CDC is committed to continued support for the people of Flint through our Childhood Lead Poisoning Prevention program and efforts to raise awareness and promote action to address the critical public health issue in communities across the country."

Elevated lead levels in children are particularly dangerous and can result in a variety of symptoms like headaches, stomach pains, behavioral problems and anemia. The city of Flint, facing a financial emergency, switched to the Flint River in 2014 as a source for their water in order to save millions of dollars. Residents complained about the water’s color, taste and odor and, although the city asserted at the time that the water was safe, chlorine byproducts connected to cancer were later found. The water also tested in 2015 for high levels of lead, leading to public outrage and national media attention, calls for Michigan Gov. Rick Snyder’s resignation for his handling of the crisis and a visit from President Barack Obama and presidential candidates.

Facing mounting pressure and public distress following the lead discoveries, the city of Flint reconnected to Detroit water last October. Officials at the time expected it to take three weeks for the water to clear through all of the pipes in the city. Citizens relied on bottled water shipped in from around the country to drink and bathe during the crisis.

The likelihood that children would have toxic levels of lead in their blood during the time that Flint River water was being used was 50 percent higher than before the switch from Detroit water. The CDC is still recommending that children who drank the water get checked by a doctor.