Metro air improves as smog, vog subside

MANILA, Philippines — Air quality in Metro Manila and nearby provinces has returned to normal, as the pollution-related smog in the metropolis as well as the volcanic smog or vog from Taal Volcano have cleared, according to the Department of Environment and Natural Resources (DENR).

The Air Quality Index (AQI), monitored on a 24-hour basis, showed particulate matter (PM) – or fine particles that can enter the deeper part of the lungs and blood – at 2.5 or in “good” quality in Caloocan City, Makati City, Parañaque, Pateros and Batangas.

The cities of Mandaluyong, San Juan and Taguig also recorded improving air quality.

The AQI monitors six criteria pollutants to determine how clean or polluted the air is and measures ground level 24-hour particulate matter if it exceeds the guideline value of 35 micrograms per normal cubic meter (µg/Ncm).

The AQI values in Metro Manila ranged between six and 38, which are considered in the good category.

The higher the AQI means that there is a greater level of air pollution in the area, which reached as high as 217 points in Paranaque City on Friday.

The DENR-Environmental Management Bureau (DENR-EMB) noted that the surface wind direction was toward the west and southwest, away from Manila.

Rains and thunderstorms and the low-pressure area have also contributed to the clearing of the smog.

“Further, scattered rainshowers were also observed which may naturally scrub gasses and particles, resulting in lower pollution concentration,” the advisory said.

Only Antipolo City measured at an AQI of 145, which is considered unhealthy especially for sensitive groups, according to DENR-EMB.

The bureau also attributed air pollution in Antipolo to emissions from heavy vehicular traffic, especially