NEW YORK (CBSNewYork) — A study by Columbia University has found potentially harmful levels of lead in the soil of some Brooklyn neighborhoods, causing a higher risk of children having elevated lead levels in their blood.

A post published Monday on the university’s Earth Institute blog warned preliminary results showed more than 9 in 10 samples from backyards in Greenpoint showed levels above the EPA safe limit for lead.

“Some yards contain seven or eight times more lead than they should – higher than the levels found in some polluted Peruvian mining communities,” according to the report.

The report also found children in Greenpoint are about four times more likely to have lead poisoning than children in other New York City neighborhoods, and 1 in 20 children had lead levels at which the Centers for Disesae Control and Prevention recommended immediate action.

The soil samples were collected by the university from 264 volunteer donations collected from 52 private backyards throughout all five boroughs since spring 2017.

Concerns about lead exposure to children peaked last year when Flint, Michigan, discovered high lead levels in the city’s public water supply.

“Even low levels of lead – especially if exposure to low levels continues over many months – is going to cause some degree of brain damage to at least some of the children who have been exposed,” said Dr. Philip Landrigan, Dean of Global Health at Mount Sinai School of Medicine.

Exposed children are at risk for a number of problems, including lower IQ scores, developmental delays and behavioral issues such as Attention Deficit Hyperactivity Disorder. Even after lead exposure stops, the effects can last for years or even be permanent.

In an unrelated study, reports of elevated lead levels in some New York City schools’ drinking water prompted a call to action last March. P.S. 11 in Manhattan and P.S. 124 in Brooklyn were among the schools where water fountains were made off-limits at the time.

There are no known drugs to effectively reverse the developmental damage caused by lead.

Something called “chelation therapy” can remove lead from the body. But so far, it has not been helpful in treating the behavioral or neurological problems caused by lead exposure.

The ongoing study’s researchers continue to offer free soil testing for backyards in north Brooklyn.

Interested participants can apply here for more information.