Air Pollution and Contribution of Different kinds of diesel Vehicles to the Particulate Matter Emissions in Sri Lanka Sugath Yalegama (AirMAC) and N Senanayake (NRMC)

Air Pollution Sources Power Sector Relatively low rate of per capita energy consumption of 1361kg of oil equivalent The three principal sources of primary energy used in Sri Lanka constitute 57.1% from biomass, 11.4 % from hydropower and 31.5% from petroleum oil products The forecast for annual power consumption during the period indicates a heavy shortfall between demand and supply, which is expected to meet by thermal power. Therefore this sector will be a major source of air pollution in future

A. P. Sources Industrial sector In developed countries Industrial sector is the main source of air pollution. In Sri Lanka it is low but most industries are concentrated in main cities while some are spread sporadically but sparsely in the country and therefore localized The major pollutant in industrial sector is SO 2 and Particulate Matter.

A.P. Sources Domestic Sector In near future the cooking in main cities where 60% of the population is changing to LPG use curtailing the pollutant load to air significantly. Transport sector Main source of air pollution in Sri Lanka is by this sector especially in major cities worst of which is Colombo. This is supported by the fact that pollutant levels increase around 9.00hours and 17.00hours when people open and close workplaces for the day

A.P. Sources Diesel vs Petrol In Sri Lanka diesel powered vehicle are more popular due to tax structure and mostly used by the people They contribute to air pollution though high emissions. Most of these vehicle engines are under compression

Indicators Data from hospital admissions shows a definite increase in respiratory illnesses in the last decade. The number of bronchial asthma cases has increased from 62,574 in 1985 to 149,258 in 1996, which is an increase of 240%

About PM 10 PM10 is a key pollutant that poses a significant threat in urban areas of Sri Lanka which cause premature death, aggravation of respiratory and cardiovascular diseases etc Most of the urban areas of Sri Lanka are affected adversely by the emissions of diesel vehicles. The color of filter papers used to collect PM10 provides evidence for the level of particulate pollution caused by the vehicles. The filter papers are carbon black.

Sri Lanka Situation

Dose-Response Relationships

Contribution from Vehicles

Vehicle Population Increase and Fuel Use ,522 12,853 13,952 15,454 15,715 14,947 15,267 17,805 21,568 18,267 Millions DieselPetrol Fuel Consumption by the Road Transport ( )

Research and Methodology Research : Percentage Contributions of PM10 from different types of diesel vehicles – major three types Methodology: The emission levels of a randomly selected sample of each vehicle type (minimum 30 vehicles from each vehicle category) were measured using the Opaci-meter. Mean k factors were calculated for each category and relative emission loads from each category were calculated multiplying the mean k factors by total number of vehicles in each category and number of kilometers traveled by those vehicle types. The methodology adopted in the study assumes that the k factor of diesel vehicles measured using the snap acceleration technique is directly proportional to the emission load of PM10 from that particular vehicle. The differences in emission load due to different traffic conditions were considered similar in case of all types of vehicles. Contributions from more polluting vehicles were assumed to be compensated by less polluting vehicles so that making the average pollution level the same.

K factor patterns

Calculations Mean k factor of light duty vehicles = Mean k factor of lorries = 5.72 Mean k factor of buses = 5.89 Pollution loads from each vehicle types (Calculated by multiplying mean k factor * number of vehicle * number of kilometers traveled per annum) For light duty vehicles= (63.24%) For buses= (9.94%) For lorries= (26.81%)

Discussion It shows around two-third contribution to particulate matter pollution from light duty vehicles. It should have the attention of the government on giving subsidies to diesel to facilitate passenger and goods transportation. Who are really benefited and threatened by the government subsidy should be seriously considered and required fiscal policy measures should be taken.