Abstract
Substantial improvements in air quality can be obtained through the introduction of cleaner fuels and vehicle technology, treated as a system. Regulations on vehicle emissions need to be set in harmony with regulations on fuel standards in light of the prevailing automotive technologies, being set to allow satisfactory operation of vehicles while limiting emissions. The emission levels of two pollutants-lead & so2 are directly related to fuel composition. Eliminating lead from gasoline, which is not naturally found in gasoline but added to enhance octane will eliminate lead emissions associated with fuel combustion from all gasoline-powered vehicles. Compressed Natural Gas [CNG] is free from carcinogenic compositions. The gasoline motor vehicles including two strokes Baby Taxis were contributed about 48% of the PM2.2 mass of both areas in Dhaka, Bangladesh. PMF modeling could resolve about 3% of the total PM2.2 mass as re-suspended / fugitive Pb. Before the banning of two-stroke engine based baby taxies, the ambient air quality of Dhaka City was one of the poorest in the world. For example, the level of suspended particulate matter (SPM) measured by the Department of Environment (DoE) & Bangladesh Atomic Energy Commission varied from 1500 ppm to 1850 ppm during 1995-20001, whereas the allowable limit for SPM is 400 ppm (DoE. 1997). About 35%-40% of the SPM and 25%-30% of the hydrocarbon (HC) emissions were contributed by the two-stroke gasoline baby-taxies.
Eventually, mounting pressure from the civil society, NGOs and the public at large forced the government to ban the two stroke baby taxies. The decision had been implemented in two phases: between September 2002 and December 2002, some 5,500 baby-taxies, which were supposedly in good conditions, were allowed to operate; but a total ban was imposed from December 2002.
Along with this "green" initiative, the government expressed its willingness promote compressed natural gas (CNG) as a cleaner, alternative fuel. The government also wanted to convert all publicly owned transports to CNG by the year 2004. At the same time, the private sector has been encouraged to import more CNG vehicles, and convert the vehicles runned by petrol, diesel and octane to CNG operated ones.
Akhtar Hossain Babu
General Secretary
Society for Urban Environmental Protection
16/13 Modhubagh, Moghbazar, Dhaka-1217.
Phone-880-2-8355764,
E-Mail: suep@hrcworks.com
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