August 31, 2021 — The health dangers of volcanic eruptions form part of the research thrust of UP Manila College of Arts and Sciences Committee on Planetary Health. The thrust seeks to assess the cost of disasters to humans whether from forced movement of people or the harmful effects to safety and health. Issues in sharing information and collection of samples and measurements to characterize disasters are being studied. Such studies would create and enhance knowledge that would be instrumental in planning for future disasters like volcanic eruptions.

The proximity of the 24 active volcanoes in the Philippines to several cities, towns, and communities exposes their residents and environment to the hazards and risks of volcano eruptions; as in the case of Mt. Mayon and Taal Volcano. 

Two years after and similar to Mt. Mayon’s eruption in 2018, the Taal Volcano eruption in January 2020 spewed ash that put the safety and respiratory health of the surrounding communities at risk. Ashfall was even observed in the National Capital Region and adjacent provinces such as Laguna that jeopardized the health of the residents. 

The ashfall damaged human and animal lives, agriculture, properties, and even affected the fish—mainly tilapia and milkfish—being raised in thousands of aquaculture pens in Taal Lake.

One reason for the massive destruction was the lack of LGU disaster response plan in some areas. This plan should address evacuation planning for the residents, displacement of thousands of residents, issues on information dissemination between Phivolcs and LGUs, and lack of appropriate face masks for the vulnerable population in the affected communities. 

Recently, it was reported in https://cleanairasia.org that as of 1 July 2021, an alert level status 3 was declared around Taal volcano. Evacuation among residents in surrounding towns such as Laurel and Agoncillo has been taking place. In terms of air quality, Clean Air Asia suggests that another inhalable hazardous element, sulfur dioxide, was released from the volcano. Sulfur dioxide would form sulfates that are the precursor of secondary particle formation leading to higher levels of pollution. Collection of particulate matter samples in surrounding areas would allow profiling the sources of air pollution from such a volcanic eruption.

The Committee on Planetary Health would like to present the study conducted by Ms. Jelle Ayz Beo, a UPM-CAS alumna. The study involved the collection of inhalable ash samples during the Mt. Mayon eruption in 2018 and the characterization of the samples based on its mass concentration, size distribution, and elemental composition. The characterization and categorization will help in the conduct of proper respiratory risk assessment.

The study revealed the magnitude of volcanic ash emitted by Mayon Volcano during a series of volcanic events in January 2018 and its impact on health. Volcanic ash (VA) was defined in the study as fragmented pyroclastic material < 2 mm in size. Inhalation of these particles can cause adverse health effects due to potentially toxic components and adsorbed bio-toxic compounds from volcanic fumes. Susceptibility to respiratory diseases increases if an individual is exposed to high concentration of particles that are small enough to penetrate the lungs. Particles < 10 μm in size (PM10) are called the inhalable fraction whereas particles < 2.5 μm in size (PM2.5) are called the respirable fraction. PM10 may enter the bronchioles and can cause lung irritation, inflammation, asthma, and bronchitis. On the other hand, PM2.5 has the ability to enter the alveolar region of the lungs, increasing the risk of acquiring chronic respiratory diseases such as silicosis. 

Based on her collected samples from Guinobatan, Ligao City, and Legazpi City in Albay, the levels of particulate matter PM2.5, were 745.54 μg/m3, 177.04 μg/ m3, and 42.79 μg/m3, respectively; which were all above the cut-off of 25 μg/m3 set by the World Health Organization (WHO). The differences in the levels of particulate matter can be partly attributed to wind patterns during the eruption. The bulk of the collected inhalable samples were also in the 0.5-1.0 μm range in terms of particle size. The collected ash samples were fine enough to pass through the respiratory tract and readily settle at the alveoli, potentially causing adverse effects on the health of the concerned persons. 

The study also showed that the mean silica content was above the limits set by the International Volcanic and Health Hazards Network for the samples collected in Guinobatan and in Legazpi City. A respiratory depositio-n dose was also estimated based on the mass concentration of the collected inhalable ash. 

The high levels of inhalable silica and fine particles measured during the eruption of Mt. Mayon gave an idea of their impact on the respiratory health of the residents in the nearby communities. Collected data combined with wind patterns were also seen to determine the distribution of inhalable ash.

Migel Antonio Catalig
 

*This article is from a series of features created by the UP Manila College of Arts and Sciences Committee on Planetary Health of UP Manila and is a follow-up to an earlier article on Planetary Health published in a previous issue. Representing various fields from the social sciences and the natural and physical sciences, the committee embodies the interdisciplinary nature of planetary health research and is working to raise awareness and interest on planetary health through research, publication, and public forums.

Featured in the UP Manila Healthscape (Special COVID-19 Issue No. 30, August 2021)