The Department of Environment and Natural Resources (DENR) has reported that, due to the Metro Manila and subsequently Luzon-wide lockdown, the air quality in the National Capital Region (NCR) has significantly improved. Various air quality monitoring stations in Metro Manila registered pollution at their lowest levels.

The Air Quality Information System of the DENR-Environment Management Bureau (EMB) showed a significant drop in the concentration of Particulate Matter (PM) in Metro Manila’s air quality, based on the results gathered from air monitoring stations in the cities of Las Pinas, Marikina, Muntinlupa, and Paranaque.

On March 22, 2020, the 24-hour average level for PM10 in Las Piñas and Marikina went down to 31.67 and 27.21 micrograms per normal cubic meter (ug/Ncm) from a high of 57.81 and 31.28 ug/Ncm, respectively, on March 9, 2020. The acceptable threshold standard level of PM 10 is 60 ug/Ncm.

In Muntinlupa and Paranaque, PM 2.5 levels on March 22, 2020, were recorded at 10.78 and 14.29 ug/Ncm, respectively — much lower when they were recorded at 28.75 and 27.23 ug/Ncm, respectively, on March 10, 2020. Based on DENR Administrative Order No. 2013-13, the acceptable limit for PM 2.5 is 50 ug/Ncm for the short term 24-hour average level, and 35 µg/Ncm for the long term one-year average level.

“We can see the drastic drop in numbers of PM 2.5 in Muntinlupa and Paranaque, and the drop in numbers of PM 10 in Las Pinas and Marikina. This explains why our sky now is clear and looks clean,” said DENR Undersecretary, Benny Antiporda.

 “The sudden stop of activities in many countries allows the earth to heal from environmental degradation," said DENR Secretary, Roy A. Cimatu, on the bright side of the COVID-19 crisis. "The major cause of climate change — air pollution, due mainly to mass transport energy emissions, is being abated. In the same way, there is less trash in public places because people are in strict home quarantine and restaurants are closed.”

The number 2.5 in PM 2.5 refers to the diameter in micrometers or micron of the fine mixture of minute solid particles and liquid droplets present in the atmosphere. When inhaled, these can affect the heart and lungs. PM 2.5 particles come from emissions of motor vehicles, fossil fuel power plants, and wood burnings, among others. PM 10 are typically from emissions of crushing and grinding machines and dust from cemented and dirt roads.

Do you think that the temporary suspension of smoke-belching PUVs is largely responsible for the cleaner Metro Manila air we now have?