Haze over Metro Manla not Taal Volcano vog, but pollution – Phivolcs

Metro Manila (CNN Philippines, June 29) — The Philippine Institute of Volcanology and Seismology clarified on Tuesday that the haze blanketing Metro Manila is not caused by volcanic smog from Taal Volcano but due to pollution from "human activities," such as vehicle emissions.

"Volcanic smog has no contribution in the haze over Metro Manila. The steam and gas plume over Taal Volcano is towards the northeast and not towards Metro Manila. Hence the haze or smog in Metro Manila is not from Taal," Phivolcs Director Renato Solidum told CNN Philippines.

Philvocs made the clarification after warning on Monday afternoon that the high level of sulfur dioxide gas emission from Taal in Batangas could lead to health problems for nearby residents. It said Taal on Monday emitted 14,326 tons of sulfur dioxide. But the warning was apparently not related to the blurry skies in the national capital region.

Solidum said the smog will become more visible in Metro Manila as more vehicles go out.

"The haze is from the ground and moving up and very evident in major roads. The smog would eventually rise farther up as air temperature would increase during the day," he explained.

In another interview with CNN Philippines, Solidum further explained: "So usually po, kapag sa araw ang hangin ay mas mainit sa baba at habang umaakyat ay lumalamig. Pero dahil po sa tinatawag na temperature na nagbabago ay meron pong dahilan kung bakit hindi umaangat ang usok at meron pong barrier."

[Translation: So usually, the air on the ground is warmer in the day and it gets cooler as it rises. But changing temperatures prevent the haze from rising and there is a barrier.]

"Para itong mga usok galing sa bulkan na nandiyan sa Taal Volcano at usok sa mga sasakyan na hindi makaangat. Na-trap po sila at ito po ay dahil sa isang weather system na pumipigil sa pagtaas ng hangin," he added.

[Translation: So the smog coming from Taal Volcano and from the vehicles are not rising. They were trapped because of a weather system that prevents the air from rising.]

Data from the Department of Environment and Natural Resources website show that as of around 11:00 a.m. Tuesday, air quality in parts of Metro Manila was either at good or moderate level.