The Wabasha-Kellogg School District in southeast Minnesota is making some changes for the start of the school year after mold was found in some elementary school classrooms late last month. 

According to district officials, an environmental health and safety consulting firm was notified out of concern, and work to clean the rooms began after testing was done. Test results then showed higher levels of common mold spores in "several" classrooms. District officials wrote on social media the higher levels suggested moisture issues that needed to be addressed and are "often linked to humidity or water damage." 

A professional cleaning company was brought in for vacuuming and disinfecting both carpets and all horizontal surfaces. In addition, fans, dehumidifiers and air scrubbers were brought in for treatment. 

Although many people may not have symptoms when exposed to these types of mold, Superintendent Nels Onstad said anyone with asthma, allergies or a weakened immune system may experience coughing, worsening asthma symptoms, as well as throat or eye irritation. 

Onstad wrote that the district couldn't "in good faith begin the school year until we are confident that our classrooms are safe for students and staff." 

According to the district, it was told by its health and safety consulting firm that they're working with five other schools and three county offices, which are having the same issue. The firm said due to the extreme humidity, heat and rain over the summer, conditions were created that allowed mold to develop faster. However, due to the ongoing construction project, there wasn't as much dehumidification happening at the site, which likely caused conditions to deteriorate.

Cleanup continued over the holiday weekend, and Onstad said an open house will now be held next Monday, while the first day of school will be next Tuesday. However, all elementary classrooms are being temporarily moved to other spaces in the building.

Workers are still removing insulation and damaged sheetrock, replacing ceiling tiles, inspecting and cleaning the HVAC system, deep cleaning of classrooms and furniture and doing safety tests. 

In addition, Onstad says upgrades will need to be made to the roof and HVAC, as well as windows and classrooms.