MANILA, Philippines – Volcanic smog or vog has been observed over Taal Lake due to the continuous release of gas from Taal Volcano in the province of Batangas.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said in an advisory on Friday, September 15, that vog “has been affecting the Taal region since the first week of September 2023” as degassing persists.

On Friday alone, Phivolcs recorded 3,264 tons per day of sulfur dioxide (SO2) emission from Taal’s main crater.

SO2 is a major gas component of magma.

Steam plumes that were 3,000 meters high also rose from the Taal Main Crater Lake on Friday.

The volcano has been under Alert Level 1 or “in abnormal condition” since July 11, 2022, or more than a year.

Around two months ago, in mid-July, Phivolcs had warned of “low-level activity” at Taal, including spikes in SO2 levels.

“As a reminder, vog consists of fine droplets containing volcanic gas such as SO2 which is acidic and can cause irritation of the eyes, throat, and respiratory tract,” the agency reiterated in its Friday advisory.

People with respiratory and heart illnesses, the elderly, pregnant women, and children are most vulnerable to vog.

Phivolcs advised those affected by vog to stay indoors, shut doors and windows, use N95 face masks, and seek medical help if needed.

Entry into Taal Volcano Island should also remain prohibited due to the possibility of “sudden steam-driven or phreatic explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas.” The island is considered a permanent danger zone. – Rappler.com