At that time, PM2.5 data was considered too politically sensitive and so the government was keeping it secret, but citizens were becoming aware of its harmful human health effects, and they were demanding greater transparency on the part of the government.
En ese momento los datos PM 2,5 se  consideraban muy sensibles politicamente y el gobierno los mantenía en secreto. Pero la población se estaba dando cuenta de los efectos dañinos a la salud humana, y demandaban mayor transparencia al gobierno.