More than 1,500 New York City public school classrooms still need work to make their ventilation safe enough for students to return amid the ongoing COVID-19 pandemic, according to data analyzed by WNYC/Gothamist. Another 104 classrooms have been indefinitely taken out of commission.

The city’s Department of Education (DOE) has pledged to complete these repairs before school starts, and hundreds of classrooms have been upgraded over the past year. Nevertheless, the size of the task is daunting, as 1 million students prepare to return to the nation’s largest public school system, which has also refused to offer a broad remote option this term.

WNYC/Gothamist has compiled the individual ventilation surveys collected by the DOE for its school buildings. Based on this data—now available below as an interactive map—the city is reporting 97% of its classrooms’ ventilation systems are working as designed, thanks to a speedy audit, two summers of repairs and the acquisition of air filters.

Morning Edition host Kerry Nolan speaks with health and science data reporter Jaclyn Jeffrey-Wilensky about the data and what you can do to check your child’s school.

Click listen in the player, and for an interactive map of ventilation in New York City schools, head to Gothamist.