Impact of banning of two-stroke engines on airborne particulate matter concentrations in Dhaka, Bangladesh.
Vehicular air pollution is common in growing metropolitan areas throughout the world. Vehicular emissions of fine particles are particularly harmful because they occur near ground level, close to where people live and work. Two-stroke engines represented an important contribution to the motor vehicle emissions where they constitute approximately half of the total vehicle fleet in Dhaka city. Two-stroke engines have lower fuel efficiency than four-stroke engines, and they emit as much of an order of magnitude and more particulate matter (PM) than four-stroke engines of similar size. To eliminate their impact on air quality, the government of Bangladesh promulgated an order banning all two-stroke engines from the roads in Dhaka starting on December 31, 2002. The effect of the banning of two-stroke engines on airborne PM was studied at the Farm Gate air quality-monitoring station in Dhaka (capital of Bangladesh), a hot spot with very high-pollutant concentrations because of its proximity to major roadways. The samples were collected using a "Gent" stacked filter unit in two fractions of 0-2.2 microm and 2.2-10 microm sizes. Samples of fine and coarse fractions of airborne PM collected from 2000 to 2004 were studied. It has been found that the fine PM and black carbon concentrations decreased from the previous years because of the banning of two-stroke engine baby taxies.
Begum
Bilkis A
BA
Chemistry Division, Atomic Energy Centre, Dhaka, Bangladesh.
Biswas
Swapan K
SK
Hopke
Philip K
PK
D000393:Air Pollutants / Q000032:analysis* / Q000592:standards; D000397:Air Pollution / Q000331:legislation & jurisprudence / Q000517:prevention & control*; D001459:Bangladesh; D002244:Carbon / Q000032:analysis; D002947:Cities; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring; D033161:Government Regulation; D018986:Motor Vehicles / Q000145:classification / Q000331:legislation & jurisprudence*; D001335:Vehicle Emissions
D000393:Air Pollutants; D004391:Dust; D001335:Vehicle Emissions; D002244:Carbon