The Department of Environment and Natural Resources (DENR) said that the rain in Metro Manila helped wash out air pollutants causing smog.

In an interview with DZRH, DENR Undersecretary Mitch Cuna said that the thermal inversion happened on Friday.

“Aside from thermal inversion, mas nagma-manifest siya dahil natatrap ang pollutants dahil sa phenomenon na iyon,” he said.

Cuna explained that the smog was caused by the extreme heat of the weather throughout the day, and at night, the pollutants are trapped from rising into the upper atmosphere until they manifest through smog.

“Ang nangyayari, because of the heat, napipigilan ang pag-akyat ng pollutants, which would be the natural course na aakyat ang pollutants. Nata-trap siya for a time, lalo na kung lumalamig,” he said.

He clarified that the Taal Volcano’s eruption was not resulting from the smog experienced in Metro Manila on Friday, as the wind direction was different.

According to him, DENR’s Air Quality Index also recorded smog in Metro Manila on September 7, 9, and 21, but it was not much noticed until Friday when it was connected to the Taal Volcano.