Air quality this week was poor across Sri Lanka compared to the previous. The western province recorded AQI exceeding 158 in Battaramulla (CEA). None of the stations recorded Good AQI during this week. Polluted air was transported from the Industrialized Kolkata region at the beginning of the week. Air pollution decreased across Sri Lanka by the end of the week except for Western Province. The reason for this is that the wind pattern changed towards arriving from North-East India. Likely wind circulation did not flush residual pollution air as much in the Western Province and Galle.

Summaries for the stations from 17- 23 February 2025

Air Quality was,

  • Unhealthy for sensitive groups (AQI 100-150): Colombo (Gregory Road), Colombo (US Embassy), Battaramulla (Pelawatte), Battaramulla (CEA), Gampaha, Negombo, Trincomalee, and Jaffna.
  • Moderate (AQI 50-100): Digana, Nuwara Eliya, Kurunegala, Ambalantota, and Puttalam.
Weekly Air Quality in Selected Towns of Sri Lanka (17 Feb – 23 Feb 2025)

Pelawatte and Battaramulla (CEA) recorded the highest weekly average AQI of 135. Puttalam recorded the lowest weekly AQI of 58.

 

Observed fine particulate measurements by the minute for last week

 

Weekly Air Quality in Selected Towns of Sri Lanka (17 Feb – 23 Feb 2025)

The AQ variation at a fine temporal scale is shown in Colombo and Pelawatte for last three days. The peak value in Colombo was about 155 and Pelawatte was about 170.

 

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 (17 Feb – 23 Feb 2025)

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