This week, air pollution in Sri Lanka worsened, with the Air Quality Index (AQI) ranging from 48 to 94, compared to last week’s range of 58 to 139. None of the stations recorded a good AQI. Akurana and Digana had high air pollution from 28 – 30 March. Last week, Akurana recorded the highest pollution level, with a weekly average AQI of 139, while Puttalam had the least pollution, with a weekly average AQI of 58.

At the beginning of the week, polluted air was coming from areas north of the Bay of Bengal. The wind shifted by the end of the week, bringing polluted air from land to the northeast of the Bay of Bengal.

Summaries for the stations from 24 – 30 March 2025

Air Quality was:

· Unhealthy for sensitive groups (AQI 100 – 150): Akurana, Digana, Battaramulla, Trincomalee, Jaffna, and Dambulla.

· Moderate (AQI 50-100): Nuwara Eliya, Kurunegala, Colombo, Gampaha, Negombo, Ambalantota, and Puttalam.

Weekly Air Quality in Selected Towns of Sri Lanka (24 Mar – 30 Mar 2025)

Akurana recorded the highest weekly average AQI of 139. Puttalam recorded the lowest weekly AQI of 58.

Air Quality impact on human health

 

Fine particulate matter (PM 2.5) are generally 2.5 microns and smaller in size. Such particles are inhalable and easily lodges inside the lungs reducing capacity. PM2.5 is a concern for people’s health when levels in the air are high. The levels of risk are shown in the dial shown against the US EPA air quality standards. AQ has a scale that run from 0-500, that tells you how clean or polluted your air is. Each level on the scale corresponds to a different level of health concern.

 

AIR QUALITY BASICS

Air pollution, a widely- talked and argued topic today has been a primary cause of unforeseen climatic changes, many health problems associated with respiratory diseases and ecosystem damage. Vehicular and industrial emissions, dust, burning of fossil fuels, open burning of garbage waste and natural phenomena such as volcanoes, wildfires and pollen contribute to air pollution. Polluted air consists of both particulate matter of fine dimensions and gaseous matter. The presence of these impurities decreases the pureness of the air we breathe.

 
AQI

United States Environmental Protection Agency (US EPA) has set up a standard to measure the level of air pollution by the following 5 major air pollutants:

  • Ground- level ozone (O3)
  • Particle pollution (PM2.5 and PM10)
  • Carbon monoxide (CO)
  • Sulphur dioxide (SO2)
  • Nitrogen dioxide (NO2)

Particulate matter of diameter less than 2.5 micrometers (PM2.5) and diameter less than 10 micrometers (PM10) and gases, ozone, carbon monoxide, sulphur dioxide and nitrogen dioxide have been identified as major air pollutants.

The AQI standard for ozone and particle pollution according to US EPA comprises of six categories. Each category is assigned a specific colour and corresponds to a different level of health concern. As the scale grows the air quality turns from good to extremely unhealthy.

 
Weekly Air Quality in Selected Towns of Sri Lanka (24 Mar – 30 Mar 2025)

Access to real- time air quality data from laser air quality sensoring instruments operated by FECT is available at www.cleanair.lk