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Weekly Air Quality in Selected Towns of Sri Lanka (20 – 26 October 2025)
During this week, overall air quality across regions of Sri Lanka ranged from “Good” to “Unhealthy for Sensitive Groups.” Most locations experienced “Good” to “Moderate” air quality levels, indicating generally healthy conditions with a few areas showing mild fluctuations in particulate matter.
In general, the Colombo District experienced poorer air quality due to low wind speeds and limited atmospheric ventilation. Localized air pollution in Battaramulla further contributed to elevated AQI levels compared to nearby areas. Battaramulla (Pelawatte) and Battaramulla (CEA) recorded the poorest air quality during the week, with daily AQI values reaching 109 and 116, classified as “Unhealthy for Sensitive Groups.” The highest weekly average AQI was also observed in Battaramulla (CEA) (76), while Nuwara Eliya reported the cleanest air with a weekly AQI of 6.
Summary for 20 – 26 October 2025:
Air Quality Index (AQI) levels were as follows:
- Moderate (AQI 51–100): Akurana, Digana, Colombo, Mirihana, Battaramulla(Pelawatte), Battaramulla(CEA), Chilaw, Ambalangoda
- Good (AQI 0-50): Nuwara Eliya, Kurunegala, Ambalanthota, Puttalam, Trincomalee, Jaffna, Anuradhapura
Observed fine particulate measurements by the hour for the last week.
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.
Access to real- time air quality data from laser air quality sensoring instruments operated by FECT is available at www.cleanair.lk
