The public is urged to stay indoors to reduce the impact of volcanic ash.

PETALING JAYA: The public has been urged to stay home due to poor air quality resulting from another eruption from Mount Ruang in Indonesia on Tuesday.

The Meteorological Department (METMalaysia) has also issued a Significant Meteorological Information (Sigmet) warning to aviation operators due to the entry of volcanic ash into Malaysian airspace.

Its director general, Muhammad Helmi Abdullah, said volcanic ash poses a risk to aircraft safety and potentially disrupts flight operations within the Kota Kinabalu Flight Information Region.

“Based on National Oceanic and Atmospheric Administration trajectory models, volcanic ash is expected to enter the country’s airspace and have a significant impact throughout the forecast period through May 5.”

He said METMalaysia, responsible for monitoring the movement of volcanic ash, will issue updated Sigmet advisories as necessary.

READ ALSO: Mount Ruang eruption: Malaysia Airlines resumes some flights with new schedules to Sabah and Labuan

“The public is advised to stay informed through notices published by METMalaysia through the myCuaca app and social media channels.”

University Kebangsaan Malaysia Department of Public Health Medicine Associate Professor Dr Mohd Hasni Ja’afar said those in Sabah and Sarawak, which are in the vicinity of North Sulawesi, must ensure adequate ventilation, wear protective equipment outdoors and maintain personal hygiene.

“Special attention should be paid to vulnerable groups such as children and the elderly, with immediate medical attention for any respiratory or dermatological symptoms.”

Mount Ruang spewed a vertical column of ash up to 5 kilometers high on Tuesday, and its eruptions were observed up to 20 kilometers away. The incident forced Indonesian authorities to evacuate 12,000 residents.

The eruptions also accelerated health alerts in Sabah and Sarawak due to health and environmental concerns. Coordinated efforts were also undertaken to mitigate risks and safeguard affected communities and ecosystems.

Mohd Hasni said volcanic activity could also cause earthquakes, forest fires, landslides, contaminate water sources and pose health risks to nearby communities.

“Scattered ash from eruptions contains high levels of particles, silica, sulfur and various minerals, which pose respiratory and dermatological risks.

“Unlike haze from wildfires, volcanic ash is finer and can penetrate deep into the lungs, which can lead to respiratory diseases such as asthma and silicosis.”

He said breathing ash could irritate the throat and lungs, causing coughing and difficulty breathing. It could cause long-term lung problems.

Professor Datuk Azizan Abu Samah, senior researcher at the Universiti Malaya Institute of Ocean and Earth Sciences, said the eruption could affect marine ecosystems.

“While ocean currents are generally unaffected by volcanic eruptions, the transport of volcanic dust into the ocean could alter marine habitats and trigger ecological changes, particularly along coasts.

“Currently, the main effects are expected to be felt in the area around Sulawesi, particularly in northern Sabah.

“One of the main concerns is the possibility of more nutrients entering the sea, which could increase its content and cause excessive algae growth leading to algae blooms.”

Azizan said algae blooms consume oxygen and block sunlight from entering underwater, making it difficult for coral reefs and aquatic plants to survive.

“Sensitive marine ecosystems can suffer when thick layers of volcanic dust suffocate corals and damage calcium carbonate-based organisms, such as shellfish.”

Azizan highlighted that the frequency and duration of the eruptions will determine the recovery time of the affected marine ecosystems and that it could take weeks.

“Northern Sabah may experience an increase in nutrient levels and an alteration in pH levels, while winds could transport ash to other areas.”