Some Montgomery County parents, worried about mold and other air pollutants, are angry over the school system’s recent $3.1 million request regarding “portable” classrooms, prefabricated buildings used to ease overcrowding and accommodate long-term construction.

At least four elementary schools with portables deemed unsatisfactory by a recent district air quality assessment are not slated for replacements by the start of next school year: Laytonsville, DuFeif, Burning Tree and Bradley Hills, according to information from parents and the schools’ facilities director, Joe Lavorgna.