HAVE you noticed the haze in your surroundings recently?
It is not fog that you’re seeing, but volcanic smog or “vog” coming from Taal Volcano in Batangas, and it has spread to nearby provinces and even Metro Manila.
The volcanic smog has been observed over Taal Lake since Thursday noon, according to the Philippine Institute of Volcanology and Seismology (Phivolcs).
Phivolcs said an average of 3,402 tons per day of sulfur dioxide has been degassed from Taal volcano this month.
But what exactly is this vog that has led to state volcanologists issuing a health advisory and local governments suspending classes in affected areas?
Risks on people, environment
Volcanic smog may look like fog, but there is a huge difference between them.
Fog is a visible aerosol containing tiny water droplets or ice crystals suspended in the air, and is said to be a cloud that touches the ground.
On the other hand, vog is a visible haze that is composed of sulfur dioxide and aerosols or tiny droplets which are primarily sulfuric acid and other sulfate compounds, which make it hazardous, according to the United States Geological Survey (USGS).
Its exact composition will depend on how long the volcanic plume reacted in the atmosphere, it added.
Vog could pose risks to humans and the environment.
Phivolcs said in its advisory that sulfur dioxide from vog can cause irritation of the eyes, throat, and respiratory tract, with severity “depending on the gas concentrations and durations of exposure.”
It said people with asthma, lung disease or heart disease, older adults, pregnant women, and children are sensitive to vog.
Vog may also damage or kill plants once it mixes directly with moisture on their leaves, according to the USGS.
“Sulfur dioxide (SO2) gas can also diffuse through leaves and dissolve to form acidic conditions within plant tissue,” it said.
Netizens alarmed
Netizens have turned to X to share numerous photos and videos of vog seen in their areas.
The republicasia team was among those greeted by vog while driving along Kawit, Cavite on Thursday evening. It has also spread to Noveleta and General Trias.
X user @ArvieSierraa shared a video of him walking through the vog in Indang, Cavite on Thursday.
On Friday morning, netizen @Z_SilentBlink shared on X several photos showing Makati City areas apparently blanketed in volcanic smog.
A video taken by X user @theoddguylol showed the poor visibility of Makati’s skyline due to the vog.
Netizens from towns near Taal Volcano also shared the vog situation in their respective areas.
X user @Ledd_Co showed a video of the volcanic smog surrounding Laurel, Batangas.
Meanwhile, netizen @thewoodenrobot shared that the “usually visible” Laguna De Bay could no longer be spotted from his location as it is covered with vog.
Phivolcs advised Filipinos to limit their exposure to vog by staying home and shutting their doors and windows. But for those who need to travel, they are advised to wear an N95 mask and to drink plenty of water to reduce any throat irritation or constriction.
Those who experience serious effects, especially those who belong in the sensitive group, should seek professional help, the state volcanologists advised.
Alert Level 1
Based on Phivolcs’ 5 a.m. advisory on Friday, Taal Volcano is still under Alert Level 1, meaning it is still in abnormal condition.
Under Alert Level 1, Taal Volcano may have “stream-driven or phreatic or gas driven explosions, volcanic earthquakes, minor ashfall, [and] lethal accumulations or expulsions of volcanic gas.”
Phivolcs no longer recommends entry into the Taal Volcano Island, and prohibits aircraft from flying close to the volcano.
