BEIJING (AP) — The smog is so bad even the statues wear masks. Or at least they do in pictures of a campus stunt that circulated online Tuesday as parts of northern China suffered a sixth straight day of severe pollution.

After being cooped inside because of the bad air, a psychology student at Peking University ventured out to place the masks on campus statues of Spanish novelist Miguel de Cervantes, Communist Party co-founder Li Dazhao and a sage practicing tai chi.