by Matt Rocheleau, originally published on March 24, 2016

Boston school officials are promising to step up testing for hazardous lead contamination at the system’s 38 buildings that still use tap water for drinking, including about two dozen where the water hasn’t been tested for at least six years.

The need for the enhanced testing has been highlighted by tests in recent years that found excessive lead in samples from three school buildings that were using tap water, including one where water flowing from a drinking fountain had seven times more lead than the state standard.

Children are particularly vulnerable when it comes to lead. Exposure has been linked to IQ deficits, shortened attention spans, behavioral problems, hearing damage, stunted growth, and lowered birth weight.

Less than a third of city school buildings still use tap water. The rest, 91, are using bottled water because of concerns about lead.

The school system’s testing program has complied with legal requirements, but some critics say those rules are lax. Now, school officials are promising to test more often than is required, starting at the end of this school year.

“The Boston Public Schools considers the health and well-being of its students a top priority,” spokesman Richard Weir said in a statement. “The district is committed to ensuring that students have access to clean, potable water in all of our schools.”

The 38 school buildings that use tap water for drinking do so because earlier testing showed those facilities to have acceptable lead levels in water drawn from fountains, officials said.

Concern over lead contamination has risen in the wake of the crisis in Flint, Mich., where the city’s water was recently found to be contaminated with high concentrations of the toxic chemical. The news has prompted water systems and schools around the country to look into the issue, sometimes unearthing serious problems.

City Councilor Tito Jackson, who chairs the council’s education committee, said the school system “should urgently test all of their buildings to determine whether or not the water is safe.”

Fellow councilor and education committee vice chairwoman Annissa Essaibi-George echoed his concerns and said she was pleased that the district plans to step up testing.

“My priority is that all children have access to good, safe drinking water,” she said.

The US Environmental Protection Agency recommends that schools do not use water when lead concentration exceeds 20 parts per billion. The Massachusetts Department of Environmental Protection says it holds water in schools to a stricter standard: 15 parts per billion.

The three school buildings where elevated levels were found in recent years were:

■ The Haley Elementary School in Roslindale, where a sample from a kitchen faucet in September 2015 measured at 27.1 parts per billion.

■ The Lee Academy Pilot School in Dorchester, where a sample from a kitchen faucet in October 2013 measured at 22.8 parts per billion, and another from a kitchen faucet in September 2012, when the building housed the Early Childhood Center, measured at 53.4 parts per billion.

■ The Chittick Elementary School in Mattapan, where a sample from a kitchen faucet in September 2011 measured at 46.1 parts per billion and another sample from a drinking fountain measured at 115 parts per billion.

School officials said that at all three schools, the kitchen faucets are used only for handwashing. The schools serve food that is prepared elsewhere.

As for the Chittick fountain sample containing 115 parts per billion — more than seven times the state standard — school officials said that several weeks after learning about the test result they conducted another round of testing that confirmed the high levels, and they immediately turned off the fountains at the school and switched to bottled water.

The other two school buildings still use tap water and will be included in the new testing program.

School officials said the district has a longstanding policy of notifying families of health and safety issues, including if high lead levels are found in water.

(By comparison, testing in recent months at 16 different school buildings in Flint found that every building tested had at least one sample test above 15 parts per billion. Numerous samples registered lead levels in the hundreds of parts per billion, and a few measured in the thousands, including one that measured at 2,856 parts per billion.)

Dramatic progress has been made overall in reducing lead levels in US water supplies in recent decades, but the latest research has found that no level is completely safe, particularly for children.

At 12 other Boston school buildings tested since 2010, lead levels measured below the state standard. But at five of the buildings, the results of at least one sample were still higher than the US Food and Drug Administration limit for bottled water, 5 parts per billion.

The school department said it is considering holding its buildings’ water to an even stricter standard than the state’s 15 parts per billion standard. But Weir said the new standard hasn’t been set yet.

The department said it had been planning since the spring of 2014 — before the Flint crisis made headlines — to increase testing. The department said it planned to develop a timetable for when each school would be tested and would hire an outside firm to conduct the testing. Results will be posted online.

The federal government recommends, but does not require, testing of water in schools, except for cases in which a school is considered to be its own public water system, meaning it uses its own water source, such as a well. This requirement does not apply to Boston.

Yanna Lambrinidou, an affiliate faculty member in the science and technology in society program at Virginia Tech who has researched the topic of lead in schools, said the lack of a requirement for all schools nationally to do regular testing is a serious problem.

“It’s a regulatory black hole that shouldn’t exist and should not have existed in the first place,” she said. “There’s evidence, just from the schools that are required to test, that there are problems in many schools.”

State and local governments can establish their own rules.

Massachusetts law requires each public water system (each town and city typically has its own system) to periodically collect samples from at least two water sources inside at least two different schools or early education facilities, selected on a rotating basis. The testing periods vary from every six months to every three years. Boston is required to test annually.

Lambrinidou said Massachusetts’ requirements also aren’t tough enough: “Sampling a couple of taps per school is going to give you quite a limited and a potentially misleading estimate of the amount of lead that children at the school are ingesting on a daily basis.”