State volcanologists observed volcanic smog, a type of air pollution, over Taal Volcano in the province of Batangas.

The Philippine Institute of Volcanology and Seismology (Phivolcs) issued an advisory at 6 am on Monday, June 28, saying that the volcanic smog or vog is a result of the continued sulfur dioxide (SO2) emission from the main crater.

“For the past two days, high levels of volcanic sulfur dioxide or SO2 gas emissions and steam-rich plumes that rose as much as three kilometers high have been observed from the Taal main crater,” Phivolcs said.

The emission of SO2, a major gas component of magma, averaged at 4,771 tons per day on Sunday, June 27. Phivolcs said this, combined with atmospheric conditions, led to vog “that brought a pronounced haze over the Taal Caldera region.”

Phivolcs advised areas around Taal Lake to “take necessary precautions” if SO2 emission continues at around 4,330 tons per day or vog persists.

The agency explained that the SO2 in vog is “acidic and can cause irritation of the eyes, throat, and respiratory tract in severities depending on the gas concentrations and durations of exposure.”

“People particularly sensitive to such ill effects are those with health conditions such as asthma, lung disease, and heart disease, the elderly, pregnant women, and children,” added Phivolcs.

The agency gave the following tips:

• Avoid outdoor activities, stay indoors, and shut doors and windows.
• Cover nose, ideally with an N95 face mask.
• Drink plenty of water to reduce any throat irritation or constriction.
• If belonging to any of the sensitive groups mentioned, seek help from a doctor or the barangay health unit if needed.

Taal Volcano was raised to Alert Level 2 last March 9 due to “increasing unrest.”

Phivolcs reminded the public on Monday that under Alert Level 2, there could be “sudden steam- or gas-driven explosions” and “lethal accumulations or expulsions of volcanic gas,” which would threaten areas near Taal Volcano Island.

“Venturing into [Taal Volcano Island] must therefore remain strictly prohibited,” the agency said.

In a separate bulletin at 8 am on Monday, Phivolcs also said it recorded two volcanic earthquakes in the past 24 hours. “Low-level background tremor” has been monitored since April 8.

The parameters indicate that “magmatic unrest continues to occur at shallow depths beneath the edifice.”

Taal Volcano’s last eruption was in January 2020. – Rappler.com