For years, Multnomah County has been warning people about lead contamination in the home — from paint dust to pottery.

It’s also warned about water, but with the caveat that lead in the water is not a common source of poisoning.

News that 47 Portland School District buildings have shown elevated lead levels in the water in recent years has some experts re-examining that stance.

County lead expert Perry Cabot said of 188 lead investigations done countywide in the last three years, the overwhelming source was lead paint. But almost all test subjects were under 4.

Cabot said school-aged kids simply aren’t routinely checked for lead.

“When we don’t test kids that are older, we can’t really say much about their risk factor,” he said. “So, this is sort of a new situation we’re facing here with school-aged children.”

Cabot hopes to test many school-aged kids next week as Multnomah County provides free screenings at two schools with elevated lead levels.