Metro Manila residents must wear face masks outdoors as air quality across the capital deteriorated to hazardous levels, the Office of Civil Defense (OCD) said Tuesday, April 14.

In an advisory, the OCD–National Capital Region said monitoring stations recorded pollutants reaching “unhealthy” to “very unhealthy” concentrations.

“The Office of Civil Defense – National Capital Region advises all residents in Metro Manila to wear face masks when going outdoors due to deteriorating air quality in several areas,” the agency stated.

Earlier, the Department of Environment and Natural Resources (DENR) advised the public to take precautions against harmful air pollutants after a fire broke out at the Navotas City Sanitary Landfill over the weekend.

Those who must go outside were advised to wear an N95 mask or equivalent respirator, especially vulnerable groups such as children, the elderly, pregnant women, and people with heart or lung conditions including asthma and chronic obstructive pulmonary disease (COPD).

The OCD-NCR strongly encouraged vulnerable groups to “remain indoors as much as possible.”

Regional disaster risk reduction councils have been placed on alert to monitor the surge in smog.

Similar episodes in the past led to increased hospital admissions for asthma and bronchitis. The current haze has visibly reduced visibility along major thoroughfares like EDSA and C5.

For those who cannot avoid leaving their homes, the OCD-NCR said they should limit prolonged exposure to polluted air.

Local government units are expected to monitor air sensors in their respective districts.

Residents were also encouraged to keep windows closed when air quality is poor, stay hydrated, and seek medical attention if experiencing symptoms such as coughing, difficulty breathing, or throat irritation.