Incorrect claim. In fact, WHO and experts say there is no negative impact from using masks as claimed.
More @ https://bit.ly/3jH7OVp / https://bit.ly/2EgiLwR (backup archive).
(Translated version of “[SALAH] Beberapa Dampak Negatif dari Menggunakan Masker” https://bit.ly/3hCg72T).