Albay air quality: From ‘emergency’ to ‘good’ in 24 hours

By Ernie Delgado

LEGAZPI CITY --- The air quality in Guinobatan town in Albay reached a critically dangerous level shortly after heavy ashfall from Mayon Volcano occurred on Saturday (May 2) afternoon.

Monitoring conducted by the Environmental Management Bureau (EMB) in areas surrounding Mount Mayon indicated that the air quality index measured 1,106 per cubic volume of air of inhalable particulate matter, or particulate pollution (PM), from May 2 to 3 (Saturday and Sunday).

This level was significantly higher than the normal range of 0 to 150 PM per cubic meter of air volume.

According to EMB in Bicol (EMB V), the ambient air quality reached the “emergency” level due to elevated particulate matter from the ashfall, indicating potential short-term health risks.

The good news was that about 24 hours later, the air quality dramatically improved and returned to the “good” category by 10 p.m. on Sunday (May 3), according to EMB V’s latest advisory.

EMB V reported that levels of sulfur dioxide, particulate matter, and carbon monoxide in the air inhaled in Guinobatan decreased due to the natural settling of ash and reduced volcanic activity.

This improvement was further supported by rainfall data from the weather bureau and the episodic nature of volcanic emissions, which can lead to rapid changes in air quality, as noted by EMB V.

A strombolian eruption occurred at Mayon late Saturday afternoon, followed by continuous pyroclastic density currents and heavy ash clouds. Guinobatan was the hardest hit among the areas affected by the thick ashfall.

In response to the heavy ashfall, officials advised the public to stay indoors, keep windows and doors closed, and refrain from motor vehicle and industrial activities.

EMB V monitoring during the same period in Legazpi City indicated that air quality was “good,” meaning there was little to no risk from air pollution for the residents.

EMB V also reported the absence of sulfur dioxide and particulate matter readings in other areas surrounding Mayon, including the neighboring cities of Tabaco and Ligao, due to equipment malfunction.

Although air quality has returned to satisfactory levels, EMB V reminds the public to remain vigilant and follow advisories, especially given Mayon’s ongoing effusive eruption.

The EMB V, under the Department of Environment and Natural Resources, began daily monitoring of particulate matter and sulfur dioxide on June 6, shortly after the Philippine Institute of Volcanology and Seismology raised Mayon’s alert level to 3.

These monitoring activities are aimed at assessing current environmental conditions, particularly air and water quality, which may be impacted by volcanic activities such as lava flows, sulfur gas emissions, ashfall, and other potentially hazardous substances, according to EMB Bicol. (PIA Bicol)

Heavy ashfall in Camalig, Albay (Image from Camalig, Albay Mayor Carlos Irwin Baldo Jr.)