Tasha Julius, production manager for the nonprofit Sustainable Resource Center, measured windows in a home after it was found to have lead paint, September 11, 2017, in Minneapolis. (Renee Jones Schneider, Star Tribune 2017/The Minnesota Star Tribune)

As winter-weary Minneapolis residents anticipate that special moment when they open their windows this spring, the city's Health Department wants them to use caution because of a toxic hazard — dust from lead paint.

The number of children in Minneapolis testing positive for unsafe levels of lead in their bloodstream rose for the second year in a row and is now the highest it's been in four years, according to data from the Minneapolis Health Department

Last year, 127 children had a blood lead level of 0.5 micrograms per deciliter or higher. While some of that exposure in immigrant children may have happened overseas, old windows are one of the most common places kids are exposed to lead.

"If you have kids, particularly kids who are 1 and 2 years old who are becoming more independent, they're crawling, they're walking, and a windowsill is the perfect height for a 2-year-old child," said Alex Vollmer, who supervises lead safety inspections for the city. "They just incidentally contact those surfaces. And that's how a lot of exposure happens."

Where is the biggest risk?

The most common cause of lead exposure is from dust in homes built before 1978, the year the federal government banned consumer use of lead-based paint. When high-friction surfaces like windows are disturbed, microscopic lead paint particles can easily fly up into the air we breathe, especially if the surfaces are not cleaned properly.

The city has identified clusters of childhood lead poisoning in the Central, Powderhorn Park, Phillips, Jordan and Hawthorne neighborhoods. About 75% of lead poisoning cases come from rental properties and tend to skew towards low-income populations and communities of color, according to the Health Department.

Why are we seeing this rise?

Vollmer said this increase may be attributed to children staying at home for longer periods of time due to the pandemic.

"The more time you spend at home, the more time you have [to be] exposed to these potential hazards," he said.

From 10% to 15% of recent lead poisoning cases are coming from lead-contact abroad, including among recent immigrants from countries including Syria and Afghanistan, who arrived at the end of 2021 and beginning of 2022.

How can I properly clean my windows?

The Minneapolis Health Department recommends a "working wet" method for cleaning lead paint dust out of windows. Instead of a broom or a vacuum, opt for a single-use material, like a wet paper towel, and pat down the area in order to soak up most of the lead-paint dust.

The city has a video on proper window cleaning methods.

What are common lead poisoning symptoms?

In severe cases of lead poisoning, children may exhibit flu-like symptoms such as nausea, vomiting, fever and mood swings. Less severe cases often manifest in an unassuming way, with symptoms as generic as an upset stomach.

"Really, the only way that you can tell at a lower exposures is by getting that blood lead test," Vollmer said.

The Sustainability Resource Center offers free lead level testing for kids 5 and younger, pregnant and nursing women, and contractors who work in lead-heavy industries. These are available at a variety of community events throughout the year.

I think my child might have lead poisoning. What should I do?

All children should have a blood lead test as a routine part of their annual check-ups. Physicians are required to report blood lead test results to the Minnesota Department of Health.

Following your child's visit, the Minneapolis Health Department will get in contact with you to set up a home visit with a lead inspector. If lead is found in the home, property owners must complete correction orders on their own or apply for one of the city's three grant programs that provide funds for lead-based home renovations.

Property owners are legally required to disclose that lead paint was found on their property.

How can I see if my property is safe?

Check if a previous property owner has reported lead paint in your home on the city's address portal.

A lead safe designation doesn't necessarily mean lead free, only that at the time of testing lead paint was intact and not considered a hazard. Signs that lead paint hazards have returned include chipping or peeling paint, excessive dust or paint chips in windows, or bare soil.