Lead pollution in Dhaka

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Dhaka Air Pollution :

Lead pollution in the city

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The International Atomic Energy Agency (IAEA) stated in its NewsBriefs (Bangladesh studies pollution levels. IAEA Newsbriefs. Volume 11, No. 4(73), November/December 1996: 11) that pollution levels of lead in Bangladesh are among the worl'd highest during dry season, according Dr. M. Khaliquzzaman, a chief scientific officer of Bangladesh Atomic Energy Commission (BAEC), with levels falling during periods of medium and heavy rainfall. Dr. Khaliquzzaman attributed the high lead levels to the use of leaded fuel in vehicles. He said that lead poses a public health danger, especially to children, by penetrating the lungs and entering the blood stream, and can lead to impaired intelligence.

Lead concentration in air of Dhaka in ng/m³

Season	PM 0-2.5 (Fine)	PM 2.5-10 (Coarse)	PM 0-10 (Total)
Low rainfall	463	444	907
Medium rainfall	253	239	492
Heavy rainfall	160	108	268
Near busy roads, the values may be ~10 times higher
Note: PM 0-2.5 (particle size <2.5 µ); PM 2.5-10 (particle size between 2.5-10 µ); PM stands for particulate matter

Lead dispresion and lead in gasoline in Dhaka

Year	Pb in Gasoline	Total lead dispersion
1994	0.4 ng/l	50 tons
1998	0.1 g/l	50 tons
Comment: Situation has not possibly worsened in Dhaka since 1994

Cost of lead pollution

1 µg/m³ of air Pb corresponds to 1 point decrease in IQ.
Current level of blood Pb concentration in adults in Dhaka is ~50 µg/dl.
Cost involvement for 1 µg/dl increment of blood lead in Dhaka is ~US$ 8.33 million per year (Method of calculation is linear scaling by population and per capita GDP). Component costs for children includes medical cost, infant mortality, neonatal cost and supplementary cost, and for adults include medical cost, earning loss and mortality.

Why there is Pb in Bangladesh gasoline?

Eastern Refinery processes Arabian Light Crude which lacks branch chain or cyclic hydrocarbon.
It is a small skimming refinery which perform crude distillation.
Gasoline produced has low octane number.
Lead based additiives are used to increase octane number.
One of most common additives is TEL (Tetraethyl lead).
TEL is 100% imported.
Only old rechnology automobiles (typically pre 1980 models) with soft valve seats need some Pb for lubrication in order to avoid valve recession. A lead level of ~0.02-0.05 g/l is sufficient for this. This also can be replaced by adding lubricants to unleaded gasoline. Cost of lubricant additives is ~0.3 cents.

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References

Bangladesh Studies Pollution Levels. IAEA (International Atomic Energy Agency) Newsbriefs. Vol. 11, No. 4 (73); Nov-Dec 1996: 11.
Khaliquzzaman M. Objectives, structures and expected follow-up. Paper preseneted at the Consultative Meeting on Integrated approach to vehicular air pollution control in Dhaka held between April 26-27, 1998 jointly by World Bank and Department of Environment, Government of Bangladesh.

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November 22, 1998 10:21 PM