DARAGA, Albay - Powerful volcanic mudflows propelling boulders thundered down the slopes of Mayon as the volcano entered its fifth day of relative calm after a week of eruption.
Residents of Barangay Anoling here about six kilometers southwest of Mayon's crater said they came face to face with a secondary threat last Saturday, when heavy rain loosened lava and volcanic debris deposited on the volcano's slopes, unleashing a wall of mud in a nearby channel.
No casualties were reported, but panicked residents reportedly began running and hurriedly boarded waiting buses and tricycles.
Portions of the gully floor had a fresh layer of soft mud all over them last Monday and areas that were once smooth of obstructions now have boulders with a thin covering of mud on them, observers said.
Volcanologists said barangays on Mayon's slopes are still in danger of getting buried if a strong rain occurs and washes down the debris.
But thousands of refugees have started to return home yesterday despite warnings from authorities of mudflows in case of a heavy downpour.
Cedric Daep, head of the Provincial Disaster Management Office (PDMO), said only residents of barangays within the six-kilometer permanent danger zone and the eight-kilometer expanded danger zone in Mayon's southeast quadrant are banned from leaving the evacuation centers.
However, those entering the no-man's land around Mayon are stopped by policemen and Army soldiers and told to immediately leave, he added.
The provincial Social Welfare and Development Office has reported a drop in the number of evacuees from 68,626 to 67,985 as of yesterday.
Residents who returned to Anoling, a barangay beneath Mayon's southwest flank, from packed evacuation centers said they experienced such a mudflow last Saturday and barely escaped with their lives.
Daep said his office had already identified the barangays that will be affected if mudflows loosen the volcanic debris deposited on Mayon's slopes.
Ronaldo Arboleda, a volcanologist from the Philippine Institute of Volcanology and Seismology (Phivolcs), said mudflows did not reach population centers, but that they are closely monitoring the situation as rains continued yesterday.
However, mudflows are also expected to cascade down the Padang channel on Mayon's eastern flank, and could directly hit populated areas and a major road, he added.
Phivolcs said Mayon's activity for the past observation period ending at 7 a.m. yesterday was mainly characterized by quiet and gentle lava outpouring.
A large portion of thick volcanic plume from the crater was caused by Mayon's continuous emission of 8,300 tons of sulfurous gas, the agency added.
Phivolcs said the seismic network monitored short-duration harmonic tremors and low-frequency volcanic quakes because of the continuous ascent of magma and the slight swelling of Mayon at the northwest flank.
Daep said PDMO and Phivolcs are preparing a lahar risk map to forewarn barangay leaders in high-risk areas.
Preliminary studies showed at least six barangays in Daraga and Camalig, four in Sto. Domingo, and two in Guinobatan, Ligao and Tabaco could be threatened by lahar when the rains come, he added.
He said residents of Guinobatan are already being evacuated to the tent city at the Anislag resettlement area, which is some 15.5 kilometers from the town.
Health Secretary Alfredo Romualdez Jr. told reporters yesterday his department has a two-week supply of relief goods and medicine for the evacuation centers in Albay.
He had sought technical and material support from the World Health Organization and that more relief supplies are expected to arrive soon, he added.
Bicol health director Gerardo Bayugo advised local governments affected by Mayon's eruption to observe environmental and water sanitation standards in the various evacuation centers.
The health department epidemiological team and the Albay provincial health department have disinfected a total of 31 evacuation centers as of yesterday, he added.
He said Romualdez has sent the regional health office assorted medicines including antibiotics, compact food and water jugs worth P 2.2 million to be distributed to evacuees.
A team of pulmonologists from the Lung Center of the Philippines has also arrived in Albay to help treat respiratory complications caused by ashfall, he added.
Provincial health officer Veronica Madulid said the number of evacuees suffering from acute respiratory infection have decreased from 147 to 114, cough and colds from 391 to 386, fever from 137 to 99, and diarrhea from 376 to 21.
However, cases of asthma have increased from 51 to 56, and that three new cases of chicken pox and measles have been reported, she added.
Eriberta Nepomuceno, regional director of the Department of Science and Technology (DOST), warned evacuees not to drink water from deepwell No. 3 at Gongon Elementary School and deepwell No. 2 at Bagumbayan Elementary School.
Tests made by the DOST showed that water from these wells are contaminated with rust sediments, she added.
At the labor department, Secretary Bienvenido Laguesma said the Technological Education and Skills Development Authority and the Regional Relief and Rehabilitation Service Committee will train refugees on livelihood programs.
He said 250 evacuees will be taught how to recycle paper and to make paper mache, and that 50 men from Cogon, Bagumbayan and Guinobatan town will be given training in electronics.
Meanwhile, former Rep. Edcel Lagman called on the Air Transportation Office and Phivolcs to work for the immediate resumption of commercial flights to Bicol.
Suspended air transportation in Bicol, particularly Albay, has deprived the region of tourism revenues from local and foreign tourists, he added.
He said the flight suspension has also prevented the transportation of goods to and from Bicol. ---