Schools’ defense against COVID-19 could boost air pollution

摘要

As students head back to school amid a surge in coronavirus cases — even among children — indoor air quality experts fear school districts could be buying unproven technology in hopes of combating the virus, and possibly emitting harmful pollutants instead. At issue are devices such as needlepoint bipolar ionizers, which send positive and negative ions through air ducts. The ions act like magnets, attracting airborne particles and clumping them together so that they either fall to the ground or are easier for filters to catch. Companies that market the devices claim they achieve 99% viral reduction, but independent experts who have studied the technology have found it doesn’t have nearly that same success rate in real-world classrooms.