Outdoor air pollution causes about 800,000 premature deaths and 6.4 million years of life lost. It occurs predominantly in developing countries with 65 percent being in Asia. About 81 percent of deaths and 49 percent of DALYs in people aged over 60 years are responsible in causing adverse effects of outdoor air pollution. Outdoor air pollutions cause three percent deaths in children under five and 12 percent of DALYs. WHO estimated 1,000 deaths in 2004 due to outdoor air pollution in Sri Lanka.
Power generation and industries also cause outdoor emissions in Sri Lanka. With the mega hydro-electric power plants in Sri Lanka (Upper Kotmale) shortly would increase demand to be about eight to 10 percent per annum in few years and will have to depend on coal, fossil fuels or renewable sources of energy. Emission of unhealthy levels of pollutants very close to high residential areas by industries has to be controlled by establishing pollutant control requirements. Economic cost of adverse health effects of air pollution is immense.
Effective Air Quality Monitoring approaches have discovered that benefits received from emission reductions are usually much higher than cost of implementing emission reduction measures. The findings of a study based on outdoor air quality levels of Colombo suggest that 20 percent of the asthma cases recorded at Lady Ridgway Hospital and two percent of cases reported to the National Hospital, Colombo could be attributed to (particulate matter) PM 10 pollution level in Colombo. The possible economic loss due to outdoor air pollution due to PM 2.5 in Colombo has been estimated to be about USD 7.0 million.
Air pollutants can be primary or secondary. Primary pollutants are emitted into the atmosphere from a source such as a factory chimney or exhaust pipe, or through suspension of contaminated dusts with wind. Secondary air pollutants are formed within the atmosphere itself. Air pollution contributes to considerable disease burden in Sri Lanka based on reported air quality levels in Sri Lanka, according to limited in-country epidemiological studies and evidence from epidemiological studies conducted in other countries in the region.
It is necessary to have a national level action plan to mitigate effects of air pollution and to generate in-country robust evidence to understand the actual scenarios. Exposure to air pollution is a modifiable risk factor that has remedial actions. Multidisciplinary and multi-sectoral efforts are needed from policymakers, government and private sectors, community and individuals to ensure a healthier Sri Lanka.