The Philippine Institute of Volcanology and Seismology (Phivolcs) on Tuesday afternoon, June 29, warned residents around Taal Lake against the adverse effects of Taal Volcano's smog or "vog."

It said that Taal Volcano has been producing "high levels of volcanic sulfur dioxide or SO2 gas emissions and tall, steam-rich plumes" since weekend.

In an advisory on Tuesday, Phivolcs said Taal Volcano has recorded its highest SO2 emission on Monday, June 28 at 14,326 tonnes.

"The high SO2 flux, water vapor emitted in plumes, weak air movement, and solar radiation will continue to produce volcanic smog or vog over the Taal Caldera region, particularly towards the northeast and eastern lakeshore communities along the current wind direction," Phivolcs said.

Phivolcs said it has received reports of the vog's adverse effects on some residents in the lakeshores of Tanauan City and Talisay town in Batangas, facing the Taal Volcano Island, and on some aquaculture workers at the Taal Lake.

"In view of continuous and unprecedented high SO2 degassing from Taal main crater, we recommend that health checks be conducted by local government officials on communities affected by vog to assess the severity of SO2 impacts on their constituents and to consider temporary evacuation of severely exposed residents to safer areas," Phivolcs advised.

Local government units (LGUs) were also advised to regularly check the weather and wind forecasts of the Philippine Atmospheric, Geophysical and Astronomical Services Administration to properly assess the potential exposure of their constituents.

The LGUs were also asked to monitor the activities of aquaculture workers to ensure that no one ventures too closely to Taal Volcano Island and gets exposed to lethal concentrations of volcanic SO2.

Phivolcs explained that 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.

People who may be particularly sensitive to vog are those with health conditions such as asthma, lung disease, and heart disease, the elderly, pregnant women, and children.

Phivolcs said that communities that will likely be affected by vog should be mindful of the following:

1. Limit your exposure. Avoid outdoor activities, stay indoors, and shut doors and windows to block out vog.

1. Protect yourself. Cover your nose, ideally with an N95 facemask.

1. Drink plenty of water to reduce any throat irritation or constriction. If belonging to the particularly sensitive group of people above, watch over yourself and seek help from a doctor or the barangay health unit if needed, especially if serious effects are experienced.

Science and Technology Undersecretary and Phivolcs OIC Renato Solidum Jr. on Tuesday morning clarified that the smog in Metro Manila was not from Taal Volcano but from motor vehicle and industries emissions.