- Manila’s lockdown, a response to the COVID-19 pandemic, is easing the Philippine capital’s notorious air pollution levels.
- Air pollution has been a perennial problem in the region, affecting 98% of the population and responsible for more than 4,000 deaths annually.
- Concentrations of fine particulate matter known as PM2.5 have dropped to a third of their normal levels in some parts of the city as road transport is curbed, businesses shut and personal mobility restricted.
- Experts say air pollution levels are expected to bounce back up once the lockdown lifts after April 30, but add the government should seize on the drastic change in air quality to beef up its emissions reduction strategies.
MANILA — Filipinos living in the country’s capital region have unimpeded views of the Sierra Madre mountain range — a sight not seen in decades through Manila’s notoriously polluted air.
A week after the Philippine government imposed a lockdown on its largest island, Luzon, on March 15 to contain the novel coronavirus pandemic, photos of Manila’s smog-free skyline with its mountain backdrop started circulating on social media.
Just before the lockdown, the Philippines ranked 57th out of 98 countries in IQAir AirVisual’s list of the world’s most polluted countries in 2019. Concentrations of tiny particulate matter, known as PM2.5, averaged 17.6 micrograms per cubic meter (μg/m3) last year, an increase from 14.6 μg/m3 in 2018. They exceeded the World Health Organization’s (WHO) safety limit of 10 μg/m3.
PM2.5 is defined as particulate matter that is 2.5 micrometers or smaller in diameter. These particles, a mix of soot, smoke, metals, chemicals, dust and other elements, can easily be breathed in and are associated with respiratory illnesses.
Manila’s air pollution has been linked to between 11,000 and 27,000 deaths in 2018 alone, according to a recent Greenpeace study, and affects 98% of the capital region’s 12.8 million people. The average pollution level in Metro Manila was 17.6 μg/m3 in 2019 and peaked during this past New Year’s Eve at 117 μg/m3 — a common occurrence as fireworks are lit in celebration. By January, ashfall caused by the eruption of the Taal volcano that month drove PM2.5 levels in Metro Manila to 86 μg/m3, according to the Manila Observatory.
Historically, experts expected less smog during the dry months of April and May. But data from both private organizations and the government show an even more drastic drop in air pollution levels following the imposition of the “enhanced community quarantine,” effectively the lockdown of the capital, to contain the spread of COVID-19 infections. Under the ECQ, as it’s known, public and private transportation has been cancelled, businesses forced to close, and personal mobility limited within the capital since March 15.
“This explains why our sky now is clear and looks clean,” says Benny Antiporda, undersecretary of the Department of Environment and Natural Resources (DENR).
DENR Secretary Roy Cimatu says similar lockdowns imposed in different cities around the world have allowed “the earth to heal from environmental degradation.”
Data from Airtoday.ph and the Institute of Environmental Science & Meteorology (IESM) of the University of the Philippines Diliman show PM2.5 concentrations of 7.1 ug/m3 in the northern part of Metro Manila from March 16-22, the first week of the lockdown. The same region recorded PM2.5 levels of 20 ug/m3 two weeks earlier.
“On ordinary Thursdays, the PM2.5 would peak to 38 ug/m3 during evening rush hours, which can be unhealthy to sensitive groups (such as those with respiratory diseases),” says Mylene Cayetano, head of the IESM and technical adviser of Airtoday.ph.
The PM2.5 measurements were taken at the Lung Center of the Philippines, which started housing COVID-19 patients starting this month. As part of community efforts to contain the virus, roads around hospitals have been cordoned off, bringing “positive feedback” and improving air quality, Cayetano says.
Along a portion of EDSA, the half-ring road that’s one of the most congested and heavily used thoroughfares in Metro Manila, pollution levels were also reduced. On normal days, more than 360,000 vehicles pass through EDSA, which cuts across seven of the municipalities that make up Metro Manila.
Even the southern part of the capital has enjoyed better air quality, with pollution levels dropping by half during the quarantine period, according to DENR data.
“The major cause of climate change, air pollution, due mainly by mass transport energy emissions, is being abated,” DENR’s Cimatu says. Satellite data also show the same trend.
Images from Japan’s Himawari satellite network, used by the Philippine weather bureau for monitoring, show levels of what’s known as aerosol optical depth that corresponds with lower PM2.5 concentrations. AOD is a measure of how much sunlight is absorbed or scattered by aerosols in the atmosphere, including particulate matter, and can thus be used to determine levels of air pollution.
Satellite data from March 16-25 released by the IESM show a clear reduction in atmospheric aerosols compared to the same period in 2018 and 2019. The IESM says this indicates a substantial reduction in air pollution in Metro Manila and southern Luzon. However, aerosol levels remain high in the Central Luzon and Cagayan Valley regions, both north of Metro Manila, because of agricultural burning.
But the respite for the capital region is temporary, groups say. Once Luzon’s lockdown lifts after April 30, air pollution levels are expected to bounce back up.
The bigger challenge is sustaining the air quality, says lawmaker Loren Legarda, adding that the effects of burning fossil fuel on air quality should be addressed. “This health crisis, although truly unfortunate, provided us a glimpse of the quality of the air we and our families could be enjoying if our economy utilizes more of the clean sources of energy and not fossil fuel,” she says.
Around the world, carbon emissions and air pollution have dropped because of the suspension of industrial activity, according to Greenpeace. In China, there has been a two-month pollution drop as seen in nitrogen dioxide levels based on NASA and European Space Agency (ESA) pollution monitoring satellites. The drop is estimated to have saved the lives of 4,000 children 5 years and younger, and 73,000 adults over 70 years old.
Air pollution levels have also been linked to coronavirus deaths. A recent study released by the Harvard T.H. Chan School of Public Health showed that “an increase of only 1 gram per cubic meter in fine particulate matter in the air was associated with a 15% increase in the COVID-19 death rate.”
The Philippines has 6,710 confirmed COVID-19 cases and 446 deaths as of April 23. President Rodrigo Duterte estimates the pandemic will affect the Philippines for the next two years.
Banner image of the viral photo of Metro Manila with the Sierra Madre skyline in the background. Image courtesy of Johair Siscar Addang.
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