The public is advised to take extra precaution from the volcanic smog (vog) and high emission of sulfur dioxide (S02) from Taal Volcano, the Philippine Institute of Volcanology and Seismology (Phivolcs) said Monday.
Vog is a type of air pollution caused by volcanoes. It consists of fine droplets containing volcanic gas such as SO2, which is acidic and can cause irritation of the eyes, throat, and respiratory tract in severities depending on the gas concentrations and durations of exposure.
Phivolcs earlier said that people particularly those near and in outlying areas of Taal with health conditions such as asthma, lung disease, and heart disease, as well as the elderly, pregnant women and children are sensitive to the ill effects of vog.
The S02 gas could irritate the skin, eyes, nose, throat. The aerosol particles in vog could also penetrate the lungs and could induce the symptoms of asthma.
S02 emission averaged 5,675 tonnes on August 15, and vog was observed over Taal Volcano and its vicinity, Phivolcs said.
Meanwhile, 74 volcanic earthquakes caused by movement or eruptions of magma from the volcano were recorded in the Taal Volcano for the past 24 hours. These lasted for 1 to 20 minutes.
Activity at the Main Crater was dominated by upwelling of hot volcanic fluids in its lake which generated plumes 1,800 meters tall that drifted south-southwest and northeast, Phivolcs said.
Taal Volcano has been on Alert Level 2 (decreased unrest) since July 23. Under this level, sudden steam or gas-driven explosions, volcanic earthquakes, minor ashfall, and lethal accumulations or expulsions of volcanic gas can occur and threaten areas within and around the Taal Volcano Island (TVI).
Phivolcs has advised that entry into TVI must be strictly prohibited.
It also advised local government officials to assess and strengthen the preparedness of previously evacuated barangays around Taal Lake in case of renewed unrest.