(CNN)Toxic lead was found in tap water drawn from nearly 70% of 2,797 homes across Chicago within the past two years, according to a Chicago Tribune analysis of results from the tested water.
Tap water in three of every 10 homes included in the analysis had lead concentrations above 5 parts per billion, the Tribune reported.
"Exposure is especially dangerous for young children and for pregnant women because the developing brain of a fetus in the womb or a young baby is very sensitive to lead, and even very low levels of lead exposure can cause brain injury in a child with loss of IQ and disruption of behavior," Landrigan said.
In 2016, the department expanded the free program in which Chicago residents could check water for lead, and testing of the 2,797 lead kits — with three samples each — has been completed, the statement said.
The Tribune reported that even after tap water had been running for five minutes, 9% of the homes tested had lead levels above the FDA’s bottled water standard.
The Department of Water Management’s statement said that "only 5.1% of kits had one or more samples with a lead concentration result greater or equal to the EPA Action Level of 15 parts per billion.
He said that Chicago residents should not be too concerned about lead levels in their home drinking water.
"We’ve done testing in New Orleans and frankly all around the country and honestly the Chicago results look pretty typical for a city with modern corrosion control and lead service lines," said Edwards, who was not involved in the Tribune report.
There are about half a million US children ages 1 to 5 with blood lead levels above 5 micrograms per deciliter, the reference level at which the CDC recommends that public health actions be initiated, according to the CDC.
Landrigan said the city should follow up on these findings, determine where the lead is coming from and test children’s blood for elevated lead levels.