Nitrogen dioxide in Metro Manila down to pre-Navotas landfill fire levels

The Philippine Space Agency (PhilSA) reported Thursday that nitrogen dioxide (NO₂) in Metro Manila has returned to previous levels before the fire at the Navotas Sanitary Landfill broke out.

In a statement, PhilSA said it has been two consecutive days since NO₂ numbers have dropped below the baseline of 4 10¹⁵ molecules per square cm, based on April 6 data.

NO₂ levels on April 28 had dropped to 4, while levels on April 29 were at the baseline of 5.

"Nitrogen dioxide is a pollutant produced from burning and is a component of smoke, and lower NO₂ concentrations indicate a reduction in the volume of smoke emitted from the landfill fire," read the statement.

PhilSA noted that the NO₂ levels aligned with reports that particulate matter over Metro Manila has dropped on both days.

Meanwhile, PhilSA said an estimated 31.95 hectares, or about 319,500 square meters, of land had been burnt by the fire as of April 26.

"Comparing with the burnt area estimate from 16 April, there was an estimated 0.89 hectares decrease in burnt area in the southern part of the landfill while an increase of around 3.10 hectares was detected in the eastern part," PhilSA said.

The National Disaster Risk Reduction Management Council (NDRRMC) has been furnished with a copy of the burnt areas for response plans.

"PhilSA's support through the analysis of satellite data provides wide-area coverage that assists the NDRRMC in monitoring the situation and prioritizing areas for response. By making space data accessible to stakeholders, PhilSA enables informed decision-making and strengthens disaster response,” said PhilSA.

The space agency will continue daily monitoring of satellite data until the situation normalizes.

According to the United States Environmental Protection Agency, breathing air with high levels of NO2 may irritate the airways of the human respiratory system.

In terms of environmental impact, NO2 may contribute to the formation of acid rain. — VDV, GMA News