Mount Bulusan in Sorsogon threw up a phreatic eruption on Monday morning raining ashfall on nearby towns.

The Philippine Institute of Volcanology and Seismology (Phivolcs) said the volcanic activity started at 4:36 a.m. and lasted until 5 a.m., sending a bent plume up to 4.5 kilometers which drifted in a west-southwest direction.

With that, the state seismologists placed Bulusan under Alert Level 1, which means there was an observed “slight increase in volcanic earthquake and steam activity,” and there was a slight inflation within the volcano’s edifice.

An inflation of the volcano’s edifice signals the continuous accumulation of pressurized magma within the volcano’s surface.

Phivolcs is currently monitoring four active volcanoes — Bulusan, Mayon and Taal which are under Alert Level 1, and Kanlaon which is under Alert Level 3.

Ashfall was recorded in the towns of Irosin, Magallanes and Juban.

On 21 April, seismologists reported a rise in Bulusan’s activity, citing the increase in weak and shallow tectonic earthquakes within the volcano’s edifice.

The public is barred within the four-kilometer radius of the permanent danger zone, in addition to the two-km extended danger zone within the volcano’s southeastern section due to the possible effects of pyroclastic density currents (PDCs).

The Sorsogon Provincial Information Office said the provincial government has pre-positioned 240 food packs for the municipality of Juban and 400 food packs for the municipality of Irosin.

Officials of the Bureau of Fire Protection, Philippine National Police, and Sorsogon Provincial Disaster Risk Reduction and Management Council (SPDRRMC) are conducting clearing operations on the city’s main roads after the volcano’s morning eruption.

Meanwhile, the Department of Health (DoH) on Monday warned residents living near Mt. Bulusan to stay clear of the volcano and advised the public to avoid the four-km permanent danger zone, emphasizing the dangers of ashfall.

The state seismologists placed Bulusan under Alert Level 1, which means there was an observed ‘slight increase in volcanic earthquake and steam activity.’

Ashfall from the volcano could pose serious health risks, particularly to the lungs.

Residents are advised to wear face masks, eye protection, long sleeves, and pants to minimize exposure.

In case of medical emergencies, they may call the DoH hotline at 1555 and the Bicol DoH hotline at (052) 742-5555.

The DoH also reminded the public on Sunday about the vulnerability of senior citizens to flu-related illnesses. Older adults are at higher risk due to their weakened immune systems.

The DoH stressed the importance of getting a flu vaccination, which has been proven safe and effective in providing protection against the virus.