Muntinlupa Mayor Ruffy Biazon suspended classes on Sept. 22 in all levels in public and private schools in the city due to volcanic smog from Taal Volcano. 

Biazon made the announcement on Sept. 21 as Muntinlupa’s air quality recorded an unhealthy level. 

Taal volcano on Sept. 14 (Screenshot from PHIVOLCS video) 

“Due to the Unhealthy Level of Air Quality recorded by our air quality sensors in Muntinlupa apparently caused by volcanic smog (Vog) from Taal Volcano, classes are suspended at all levels, public and private schools in Muntinlupa City, Friday, Sept. 22, 2023,” Biazon said. 

He added, “Everyone is advised to avoid going out unless it is absolutely necessary. If you need to go out, please wear your facemask and if possible, protective eyewear.”

According to the Muntinlupa City Department of Disaster Resilience and Management, the city’s PM 2.5 readings in barangays ranged from 79.63 to 87.81 as of 10:30 p.m. on Sept. 21, equivalent to an “unhealthy” air quality index level. 

The “good” air quality index has a PM2.5 level of 0 to 12 μg/ μg/m3 (micrograms per cubic meter of air). 

PM means particulate matter, “the term for a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope,” according to the website of the United States Environmental Protection Agency (EPA). 

PM2.5 refers  to  “fine inhalable particles, with diameters that are generally 2.5 micrometers and smaller.”

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) issued a Taal Volcano advisory on Sept. 21 about the volcanic smog. 

“Since 12:30 PM today, volcanic smog or vog has been observed over Taal Lake by the Taal Volcano Network and has lingered over the region until present. Vog has been affecting the Taal Region since the first week of September 2023 as an average of 3,402 tonnes/day SO2 has been degassed from Taal Volcano for the month,” according to PHIVOLCS. 

It said “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 with severities depending on the gas concentrations and durations of exposure. 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.” 

“DOST-PHIVOLCS reminds the public that Alert Level 1 prevails over Taal Volcano, which means that it is still in abnormal condition and should not be interpreted to have ceased unrest nor ceased the threat of eruptive activity,” it said.