How to prevent Air Pollution.

 

 

 

To stop air pollution, there are many things that need to be done. Things like fossil fuels should no longer be used. Also, there are other harmful things like drugs, cigarettes and garbage that cause major air pollution. 

 

We make choices everyday that can help reduce air pollution. Below are a few ideas that you can take to help clean our air.
At Home

• Conserve energy - turn off appliances and lights when you leave the room.
• Recycle paper, plastic, glass bottles, cardboard, and aluminum cans. (This conserves energy and reduces production emissions.)
• Keep woodstoves and fireplaces well maintained. You should also consider replacing old wood stoves with EPA-certified models. Visit www.epa.gov/woodstoves.
• Plant deciduous trees in locations around your home to provide shade in the summer, but to allow light in the winter.
• Buy green electricity-produced by low-or even zero-pollution facilities.
• Connect your outdoor lights to a timer or use solar lighting.
• Wash clothes with warm or cold water instead of hot.
• Lower the thermostat on your water heater to 120F.
• Use low-VOC or water-based paints, stains, finishes, and paint strippers.
• Test your home for radon-a dangerous, radioactive gas that is odorless and tasteless. If the test shows elevated levels of radon, the problem can be fixed cost effectively. Visit www.epa.gov/radon.
• Choose not to smoke in your home, especially if you have children. If you or your visitors must smoke, then smoke outside. Visit www.epa.gov/smokefree.

Buy Smart

• Buy ENERGY STAR products, including energy efficient lighting and appliances. They are environmentally friendly products. For more information, visit www.energystar.gov or call 1-888-STAR-YES.
• Choose efficient, low-polluting models of vehicles. Visit www.epa.gov/greenvehicles.
• Choose products that have less packaging and are reusable.
• Shop with a canvas bag instead of using paper and plastic bags.
• Buy rechargeable batteries for devices used frequently.

Drive Wise
Plan your trips. Save gasoline and reduce air pollution.

• Keep tires properly inflated and aligned.
• In the summertime, fill gas tank during cooler evening hours to cut down on evaporation. Avoid spilling gas and don't "top off" the tank. Replace gas tank cap tightly.
• Avoid waiting in long drive-thru lines, for example, at fast-food restaurants or banks. Park your car and go in.
• When possible, use public transportation, walk, or ride a bike.
• Get regular engine tune ups and car maintenance checks (especially for the spark plugs).
• Use an energy-conserving (EC) grade motor oil.
• Ask your employer to consider flexible work schedules or telecommuting.
• Report smoking vehicles to your local air agency.
• Join a carpool or vanpool to get to work.

For Your Health

• Check daily air quality forecasts, which tell how clean or polluted your air is, and the associated health concerns. Visit www.airnow.gov.
• Remove indoor asthma triggers from your home and avoid outdoor triggers in order to effectively control your asthma. Visit www.epa.gov/asthma to learn more about asthma triggers and ways to avoid them.
• Minimize your sun exposure. Wear sun block and UV protection sunglasses. To find out about current forecasts of UV where you live, go to www.epa.gov/sunwise/uvindex.html.

 

Muhammad Mahadi

Environmental Science Discipline.

Khulna University.

Introduction:

Air pollution is one of a variety of manmade environmental disasters that arecurrently taking place all over the world. Air pollution may be defined as an atmosphericcondition in which various substances are present at concentrations high enough abovetheir normal ambient levels to produce a measurable effect on people, animals,vegetation, or materials. ‘Substances’ refers to any natural or manmade chemicalelements or compounds capable of being airborne. These may exist in the atmosphere asgases, liquid drops, or solid particles. It includes any substance whether noxious or  benign; however, the term ‘measurable effect’ generally restricts attention to thosesubstances that cause undesirable effects. Air quality has deteriorated both due to humanactivities, and natural phenomenon such as wind blown dust particles etc. There are twomajor sources of air pollution in Bangladesh, vehicular emissions and industrialemissions. However, these are mainly concentrated in the cities. Recently, air pollutionhas received priority among environmental issues in Asia, as well as in other parts of theworld. Exposure to air pollution is the main environmental threat to human health inmany towns and cities. Particulate emission is mainly responsible for increased death rateand respiratory problems for the urban population. This problem is acute in Dhaka beingthe capital of the country and also the hub of commercial activity.Dhaka is a major,cultural, and manufacturing center. The common types of industries in and around the periphery of Dhaka are ready-made garment manufacturing, jute, tanneries, textile, tea processing, fertilizer, cement, paper and pulp, chemicals and pesticides, food and sugar, pharmaceuticals, petroleum refinery, distillery, rubber, plastics, and brick manufacturing,assembling buses, trucks, and motorcycles, assembling radios and televisions. Air of Dhaka is being polluted day by day very badly.The other urban areas i.e. Chittagong,Khulna, Bogra and Rajshahi have much lesser health problem related to urban air  pollution. The ambient atmospheric conditions have progressively deteriorated due to theunprecedented growth in numbers of motor vehicles, and continuous housing andindustrial development.

Air Pollution:

 Contamination in the atmosphere caused by the discharge, accidental or deliberates of a wide range of toxic substances. Often the amount of the releasedsubstance is relatively high in a certain locality, so the harmful effects are morenoticeable. The major sources of air pollution are transportation engines, power and heatgeneration, industrial processes and the burning of solid waste. A new source of air  pollution is an increasing 'hole' in the ozone layer in the atmosphere above Antarctica,coupled with growing evidence of global ozone depletion. Air pollution has also long been known to have an adverse effect on human beings, plants, livestock and aquaticecosystem through acid rain.

Description Of The Dhaka City :

Dhaka city is more than 400 years old. Over these years the populationhas increased many folds.Living in Dhaka is not really like living in the crater of anactive volcano but it is like living on a sleeping volcano which may erupt any time andengulf everything. Dhakaites are not fully realizing what crisis is emerging for them. In37 years of independence the capital of Bangladesh, the historic city which bears manysymbols of national pride like Language Martyr monument, Monument for martyredfreedom fighters, Historic relics of Mogul Dynasty unfortunately have become a concreteslum perspiring for fresh air& thirsty for pure drinking water. The dilapidated state of thecity mirrors the poor state of affairs of the entire nation. The water of the rivers aroundthe city is polluted, air is poisonous obnoxious particles, gas, electricity and water aregetting scarce. At last 20%of the population is living in slums in inhuman condition. Costof living has sky rocketed beyond normal peoples reach. This is not what the liberationwar was fought. Our valiant freedom fighters did not make supreme sacrifice for a Dhakacity life like this. Many people talk of realizing the dreams of freedom fighters, many talk about ideals of liberation war. But we should all be ashamed for our failures at our respective positions to serve the nation with commitment.

Fig : Map Of The Dhaka City.

Problems Of  Dhaka City:

Bangladesh capital Historic Dhaka is fast turning into an inhabitable city. Air &water are saturated with poisonous elements, sound pollution reaching unacceptable limits, gas electricity, and water supply crisis looming large, rapid depletion of subsurface water level making the city vulnerable to mild earth quake.

Dhaka city is expanding in all direction east to west, north to south, population is increasing in geometric progression but the civic amenities can no t keep pace with the growing demand. The capacity of various utilities can no longer meet the rapidly increasing demand. Supply of pure drinking water, safe accommodation for the growing population, appropriate sanitation, municipal waste collection, supply of electricity and gas for about 150 Million city dwellers are progressively turning into serious crisis. In this serious situation the news about Dhaka city air reported to containing higher proportion of lead and CO must be considered very alarming. Serious noises, unacceptable sound level is causing hearing problem. In no modern cities these days the automobiles blow horns in the heart of the city. The water of rivers around Dhaka city is nothing but poison. Even WASA Water treatment plant in Salemabad finding it very difficult to treat the poisonous water of Sitalakya. But the helpless shelter less people from villages and rural people are migrating to Dhaka compounding the problem still further. City dwellers are already affected with various contagious water borne disease. Dhaka has already turned into a slum of concrete.

Dhaka has very high air pollution level:

Air pollution has become a matter of great concern for us in recent years. Those who are living in cities in Asian countries including Dhaka have already realized how seriously air pollution has been poisoning life and degrading the environment. People living in major towns of Bangladesh experience the problems of air pollution in varied degrees.

Faulty vehicles, especially diesel run vehicles, brick kilns, and dust from roads and construction sites and toxic fumes from industries contribute to air pollution. Industrialization and mechanized vehicles are two major sources of air pollution in any country. Those are unavoidable accompaniments of increased economic activity of any country. The number of automobiles has been increasing in Dhaka city at the rate of at least 10 per cent annually, which has been contributing to air pollution on the one hand and traffic congestion on the other.

The main pollutants from gasoline powered internal combustion engines are carbon monoxide, hydrocarbons, nitrogen oxides, sulphur dioxide particulates of lead compound and unburned carbon particles. Emissions from diesel engines are smoke, carbon monoxide, unburned carbon, nitrogen oxides and sulphur dioxide.

Air pollution seriously affects the respiratory tract and causes irritation, headache, asthma, high blood pressure, heart ailments and even cancer. If this trend of air pollution continued, those living in major cities including the metropolis will become exposed to these ailments and also other complications. The mental faculty of children will be adversely affected by lead pollution, which can also affect the central nervous system and cause renal damage and hypertension.

In this context, it can be recalled that the average annual deaths from air pollution-related diseases in Delhi increased to 10,000 from the level of 7,500 in early 1990s as was revealed in a World Bank study in late 1990s. The level of small particles -- less than 10micron -- present in the air was very high, which could cause severe lung cancer, according to Delhi based Centre for Science an Environment (CSE).

The air quality of Dhaka city shows that the concentration of suspended particles in the ambient air is many times higher than normal. This air, which the city dwellers and road users regularly breathe, contains lead in concentrations reportedly almost ten times higher than the government safety standard set by the Department of Environment (DOE).

About 50 tons of leads are emitted into Dhaka city's air annually and the emission reaches its highest level in dry season (November-January), revealed a study conducted by scientists of Bangladesh Atomic Energy Commission (BAEC). The density of lead in the air of Dhaka city in dry season reaches 463 monograms, the highest in the world. The lead concentration in the polluted air of Mexico city is 383 monograms and in Mumbai, India it is 360 monograms per cubic meter.

The Environment Conservation Act, 1995 and the Environment Conservation Rules, 1997have been enacted by the Parliament. Under the Rules of 1997, Ambient Air Quality Standards, Vehicular Exhaust Emission Standards, River Transport (Mechanized) Emission Standards and Gaseous Emission for Industries or Projects Standards have been set.

The Environmental Conservation Act, 1995 also contains laws as regards the protection of environmental health and control of environmental pollution. The Supreme Court in two cases held that the “right to life”, which is enshrined as a fundamental right, includes the right to a healthy environment.

What we find is either absence or little effective cooperation of the members of the public and the concerned agencies with the Department of Environment (DOE) in implementation of laws and regulations to help reduce air pollution. DOE gets little cooperation also from the transport owners and their employees including drivers in this regard. DOE's initiatives for daily monitoring of vehicles at certain city points sometimes do not succeed due to non-availability of members of law enforcing agencies.

It may be recalled here that New Delhi in an attempt to reduce air pollution prohibited initially 20 year old vehicles from plying on city streets in late 1990s. They started phasing out 17 year old vehicles from the end of 1998. It was followed by elimination of 15 year old vehicles in 1999.

Besides registration of new auto-rickshaws with front engines was banned from 1996 and registration of old defense service and government auctioned vehicles was banned from1998. All these steps of the New Delhi authorities have created some favorable impacts in reducing air pollution and in the process have been improving the air quality.

The pollutants in the ambient air of Delhi decreased by 4-40 per cent in case of So2, 4-13 per cent in case of NO2, 6-17 per cent in case of particulate matter, 3 per cent in case of Carbon Monoxide and 11-60 per cent in case of lead during 1998, Centre for Science and Environment (CSE), a Delhi based non-government organization estimate showed.

In the past our attempts to prohibit plying of old vehicles in city streets failed either for political reasons or in the face of resistance by transport owners and their employees. But if our neighboring countries can improve air quality of their cities by banning use of old vehicles and also relocating some of their polluting industries, authorities in Bangladesh can also do so.

It is time to phase out old and black smoke emitting vehicles from city roads as our right to live in healthy environment largely depends on it. Good governance helped curb air pollution in cities like Bangkok, Kolkata, Kathmandu and Lahore while weak administration caused the increase of air pollution in Dhaka and Karachi. The problem should be high on the agenda of the government as well as political parties. Let us hope that the issue gets the priority it deserves.

 Air Pollution in Dhaka City:

• Basically, there are two major sources of air pollution in Bangladesh industrial emissions and vehicular emissions. The industrial sources include brick kilns, fertilizer factories, sugar, paper, jute and textile mills, spinning mills, tanneries, garment, bread and biscuit factories, chemical and pharmaceutical industries, cement production and processing factories, metal workshops, wooden dust from saw mills and dusts from ploughed land, and salt particles from ocean waves near the and coastal lands. These sources produce enormous amount of smokes, fumes, gases and dusts, which create the condition for the formation of fog and smog. Certain industries in Bangladesh, such as tanneries at Hazaribag in Dhaka City, emit hydrogen sulphide, ammonia, chlorine, and some other odorous chemicals that are poisonous and cause irritation and public complaints. This may cause headache and other health problems.
• With increased rate of urbanization in the country, the number of vehicles is also increasing rapidly, and contributing to more and more air pollution. The Department of Environment (DOE), and other related organizations, have identified the two-stroke engines used in auto rickshaws (baby-taxies), tempos, mini-trucks, and motorcycles as major polluters. At present, there are about65000 baby-taxies among them more than 296,000 motor vehicles ply in Dhaka City alone. Moreover, overloaded, poorly maintained and very old trucks and mini-buses are also plying the city streets emitting smokes and gases. In fact about 90% of the vehicles that ply Dhaka's streets daily are faulty, and emit smoke far exceeding the prescribed limit. Diesel vehicles emit black smoke, which contain unburned fine carbon particles.

• The air quality standards are different for residential, industrial, commercial, and sensitive areas. The worst affected areas in Dhaka city include: Hatkhola, Manik Mia Avenue, Tejgaon, Farmgate, Motijheel, Lalmatia, and Mohakhali. Surveys conducted between January 1990 and December 1999 showed that the concentration of suspended particles goes up to as high as 3,000 micrograms per cubic meter (Police Box, Farmgate, December 1999), although the allowable limits 400 micrograms per cubic meter. The sulphur dioxide in the air near Farmgatew as found to be 385 micrograms per cubic meter, where as the maximum permissible limit is 100 micrograms per cubic meter. Similarly, in the Tejgaon Industrial Area the maximum concentration of suspended particles was 1,849micrograms per cubic meter (January 1997), as opposed to the allowable limit of 500 micrograms per cubic meter. Usually the maximum concentration of air pollution in Dhaka is during the dry months of December to March.

• Also many Report states that at peak hours Dhaka air at Motijheel Commercial Area has been found to contain 100 ppm of Carbon Monoxide, the sound level reaches 80 decibels. The report also indicates that the water of Buriganga River contains alarming amount of organochloric compound which may cause cancer like DDT or may obstruct Endocrine (causing genetic problems leading to men turning women) .A survey of the Environmental Chemistry Department of the University evidenced that the water of Buriganga at half a kilometer of Hazaribagh Tannery contains about 28ppm chromium which is extremely dangerous. Usually Buriganga water contains 6-10 ppm Chromium. The wastes of Tanneries at Hazaribagh are responsible for this menace. According to the guidelines of World Health Organization (WHO) water must not contain more than 1 ppm of Chromium. This alarming level of Chromium in River water which in many ways used for human consumption is causing serious threat for human life in the city. But unfortunately Rajuk and Dhaka City Corporation are doing nothing to mitigate this menace. We have a Department of Environment (DOE),Air Pollution In Dhaka CityMuhammad MahadiEnvironmental Science Discipline.Khulna University..It is time to phase out old and black smoke emitting vehicles from city roads as our rightto live in healthy environment largely depends on it. Good governance helped curb air  pollution in cities like Bangkok, Kolkata, Kathmandu and Lahore while weak administration caused the increase of air pollution in Dhaka and Karachi. The problemshould be high on the agenda of the government as well as political parties. Let us hopethat the issue gets the priority it deserves.Air Pollution In Dhaka City : we have a very active Civil Society but wonder why this very alarming situation is escaping every ones attention. We understand the tanneries from Hazaribagh will be relocated soon to outskirts of Dhaka but if the wastes are not treated properly and disposed off carefully these will continue to pollute another water stream.

• Contribution of urban transport system to Dhaka's air pollution :

Air pollution in Dhaka is serious due to increasing population and associated motorization. Although existing air quality monitoring data is limited, it has been clearly shown that the average ambient concentrations of suspended particulate matter (SPM) and airborne lead are higher than the Bangladesh national ambient air quality standards and much higher than the WHO guidelines. The city's average SPM levels are about 2 times higher than the Bangladeshi standard of 200 µg/m3 in residential areas and are more than 10 times higher than the WHO guidelines of 120 µg/m3 (24hours) in commercial areas. Lead levels are also high compared to other cities in the world. Although there is a lack of time-series data, the ambient air quality measurements available for 1990 and 1996 onward indicate that the air pollution is worsening.

Diesel vehicles found causing 80pc of air pollution in city

Diesel-run vehicles account for more than 80 per cent of the air pollution in Dhaka as most of them fail to comply with the approved emission standard, said a recently published survey report.

About 60 per cent of the city dwellers consider motor vehicles as the main source of air  pollution, about 55 per cent consider diesel-run buses to be most polluting the air and 22 per cent feel that diesel-run trucks cause the air pollution.

Nearly 60 per cent of the dwellers said they contract diseases because of air pollution and 88 per cent believed smoke and dust are the most important air pollutants. The public perception of air pollution was revealed in the survey, Stakeholders Perception on Air Pollution by Diesel Vehicles in Dhaka City, conducted by the Air Quality Management Project of the Department of Environment and the World Bank. 

The air quality project director, Mohammad Nasiruddin, said in 2004, they conducted a study, Roadside Vehicle Emission Testing Programme in Dhaka, where they surveyed2,140 vehicles of all types to identify the principal contributors to air pollution.’ At the end of the study, we found 90 per cent of human haulers followed by 60 percent diesel-run minibus have failed to comply with the approved emission standard, as their smoke capacity is higher than 80 Hart ridge Smoke Units (HSU),’ he said, The study suggested aset of recommendations that included retirement of old-technology vehicles following a time-bound road map, introduction of low sulphur diesel, imposition of a total ban on the import of all types of old vehicles and switchover to natural gas as the main source of transport fuel.

The visible signs of ambient air quality of Dhaka is indicating an upward trend in gross emissions in recent years. Motor vehicles, especially the two strokes engine vehicles (TSEV) are responsible for the increase in emissions of both local pollutants and green house gases due to the rapid growth in the number and use of motor vehicles. Data shows that number of registered vehicles in Dhaka has grown by 60% from 1990 to 1996.TSEVs have outgrown all other types of vehicles. The following table shows the vehicle population by type, utilization, and fuel economy. 

 Data of these:

Vehicle population, utilization, and fuel economy in Dhaka, 1996 (Source: European Economic Commission; Dhaka Urban Transport Project Working Papers):

Initial estimates reveal that motor vehicles annually emit 3,700 tons of particulate matters(PM10), 8,550 tons of nitrogen oxides, 50,700 tons of carbon dioxide, etc. TSEVs(mainly 3-wheeler baby taxis) are the significant contributors.

Baseline vehicular emissions inventory in Dhaka, 1996; Unit: 1,000 tons

Two strokes engine baby taxis pollute intensively in terms of per vehicle per kilometer driven. A typical baby taxi is driven 100-120 kms per day. Thus, in 360 days of a year,Dhaka's 30,000 strong baby taxis (<17 1995="" 20million="" 25="" 32="" 360="" 62="" agency="" and="" anincreasingly="" are="" bangladesh="" but="" carbon="" compared="" contributor.="" cost="" dioxide="" economic="" emitted="" energy="" for="" gas="" global="" green="" healthrelated="" house="" hydrocarbons="" impact="" improtant="" in="" is="" its="" mono="" more="" nbsp="" nternational="" of="" on="" oxide.="" p="" per="" pm10="" publichealth="" responsible="" sector="" system="" the="" to="" tons="" total="" transport="" us="" vehicle="" vehicles="" vehicular="" warming.="" year.="">

Motorized Vehicles by Type on Road in Greater Dhaka.

 

• Air pollution in the Dhaka city Caused By Lead:

The International Atomic Energy Agency (IAEA) stated in its News Briefs (Bangladesh studies pollution levels. IAEA News briefs. Volume 11, No. 4(73), November/December 1996: 11) that pollution levels of lead in Bangladesh are among the world’s 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

 

Lead dispersion and lead in gasoline in Dhaka

  

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$ 8.33million 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 performs crude distillation.

• Gasoline produced has low octane number.

• Lead based additives are used to increase octane number.

• One of most common additives is TEL (Tetraethyl lead).

• TEL is 100% imported.

• Only old technology 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.

• Suspended Particulate Matters (SPM) in City Air : 

Department of Environment has taken 8 hours measurements at several locations along busy roads of Dhaka city. Results show SMP concentrations of 665-2456ug/m3 at Farmgate. Bangladesh standard for Commercial Area is 400 ug/m3. The SMP trends are highest during the dry season (December-March) due to increase in roadway dust, dust from dust-carrying vehicles, and increased open burning. Figure-1 shows Street side SPM levels at Farmgate, a busy traffic place in Dhaka. and figure-2 showsPM2.5 urban composition.

Figure-2. Urban Composition of Particulate Matter of Size <2 .5="" p="">

Air pollution making Dhaka city inhospitable: 

The volume of poisonous particles in the city air has reached far beyond the permissible level for human body in recent years.

The Dhaka city dwellers are always at a serious health risk due to the highly polluted air, warned health experts.

The increasingly high concentration of toxic elements in the air is causing a foggy blanket in the city sky at present, according to the experts of Air Quality Management Project (AQMP) under the Department of Environment (DoE).

The AQMP, which has been monitoring the air quality of the city since 2002, has recently lunched a website to inform the people about the air quality on daily basis.

The website reveals that the air quality of the city is lethal for human body especially during winter and post winter.

The AQMP advised the city dwellers to stay indoors as much as possible during this time to avoid health hazards from the pollution.

According to the website, poisonous carbon monoxide, sulphur dioxide, nitrogen dioxide, suspended particulate matter (PM-10) and particulate matter (PM-2.5) exist in Dhaka's air beyond permissible level for human body.

Due to increase of PM-10 and PM-2.5, people lose lung function and suffer from chronic respiratory and cardiovascular diseases while nitrogen dioxide increase risks of bronchitis and pneumonia. Nitrogen dioxide causes respiratory infection.

Carbon monoxide reduces delivery of oxygen into the human body, creates severe headache and decreases visual perception and manual dexterity.

Permissible limit of PM-10 is 65 micrograms per cubic metre and for PM-2.5 it is 150micrograms per cubic metre.

The implementation of the ban on two-stroke three-wheelers in 2003 made some temporary progress in reducing toxic elements from the air but has been marred by the functioning of old motorized vehicles and the brick kilns around the city.

Faulty vehicles are the largest source of air pollution. Only the diesel-run vehicles contribute about 60 per cent of such particles in the air, surveys of the AQMP revealed.

At least 70 per cent of the diesel-run vehicles, mainly buses and trucks, are emitting toxic particles beyond the permissible limit. Brick kilns in the northern edge of the city contribute at least 20 per cent to the air pollution.

There are 4,000 brick kilns around the city, which use tyres, wood and low-quality coal, emitting poisonous particles into the air. But no initiative has been taken yet to measure quantity of poisonous particles emitting from brick kilns.

The chimneys of the brick kilns made higher than 120-feet is not a solution to reducing the air pollution, said the AQMP officials. 

The government banned running of buses more than 20 years old in the city but failed to keep those vehicles out of the city.

The height of brick kiln chimneys has been increased to reduce air pollution but the initiative failed as the government failed to ensure quality of fuel used in the kilns.

Mohammad Nasiruddin, Director of the AQMP, said: "Phasing out of the diesel-run old and faulty vehicles could reduce air pollution to half in the city."

Effects Of Air Pollutants On Human Health: 

Carbon di-oxide (CO2): It is a major absorber of infrared radiation emitted towards thespace from the earth surface. Thus, it has crucial role in planetary temperature structure.

Carbon monoxide (CO): If inhaled, it is absorbed from the lung alveoli 300 times faster than oxygen. High concentration of CO in blood makes it difficult for heart to pump blood through arteries.

Hydrocarbons (HC): Unburnt hydrocarbon may form ozone with oxides of nitrogen which is a central nervous system depressant. Other hydrocarbons cause convulsion of CNS.

Oxides of nitrogen (NOx): Causes dilatation of air spaces in lungs. NO2 causes damages to bronchioles and alveolar ducts. NO2 is also suspected to impair the defense mechanism of respiratory system. Infants and children are more susceptible.

Particulate matter: Diesel emits suspended particulate matter (SPM) which contains shoot. Shoot is responsible for reduction of atmospheric visibility and absorb and carry organic compound to lungs.

Lead (Pb): Around 75% of the ingested lead is deposited in bones and tissues causing irreversible brain and kidney damage. Growing nervous system of young children are particularly vulnerable.

(Source: Effect on Dhaka air quality by 2-strokes engines and suggested remedies. Paper presented byUttara Motors Ltd. at a Consultative Meeting on integrated approach to vehicular pollution control held between April 26-27, 1998 in Dhaka.)

Conclusion:

Bangladesh has yet to be implemented a National Air Quality Standard, there are no detail air quality regulations based on which Environmental Impact Assessment could be done. Very few works have been done on air quality measurements and national air  pollutants estimates in Bangladesh. Author is willing to extend his assistance in doing any projects related to road traffic pollution in Bangladesh. Few recommendations are:

• A national steering committee constituting experts is urgently established to cope with the problem.

• Formulate guidelines for policy makers, city planners, traffic engineering practitioners towards mitigating traffic pollution problems and make recommendations for setting National Air Quality Standard.

• Auto-rickshaw (AR) should be restricted in Dhaka city. Consequently, an equivalent and efficient alternative mode of transport should initiate in Dhaka, so that; those who are importing AR, driving AR can do the same for the new mode of transport.

• Current initiative of taxi-cab is appreciating, however, the pre-conditions, NEW and 2000CC car seem to be policy makers ignorance in understanding modal choice in Dhaka. A pre-condition is really necessary that is "not the diesel car". As we are plagued with severe air pollution problem in Dhaka. What we need is to find an alternative equivalent of AR, that is environmentally friendly and is able to provide door-to-door service.

Mainly Motor vehicles, especially two-strokes engine vehicles are an increasingly important source of air pollution emissions in Dhaka. Further understanding of the sources of air pollution, the contribution of vehicles to air pollution emissions, and the characteristics of vehicular emission control measures is necessary to design a cost effective action plan. It is recommended that government will undertake actual measurement of emission factors, complete the emission inventory, and conduct an investigation on emission control measures. A set of cost effective technical measures are already available for controlling pollution emissions by two strokes 3-wheelers.Government should strengthen vehicle emission standards, regulations and enforcement. Measures to reduce fuel demand and improve traffic conditions are also critical to ensuring a net emission reduction and should be used as a complement to technical measures.

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Reference:

 Effect on Dhaka air quality by two strokes engines and suggested remedies. Paper presented by Uttara Motors Ltd. in a Consultative Meeting on Integrated Approach to Vehicular Pollution Control held during April 26-27, 1998 in Dhaka.

 Xie J, Brandon CJ and Shaj JJ. Fighting urban transport air pollution for local and global good : The case of two strokes engine three-wheelers in Dhaka. Paper  presented at the Consultative Meeting on Integrated approach to vehicular air  pollution control in Dhaka held by World Bank and Department of Environment, Government of Bangladesh between April 26-27, 1998.

 Khondkar Abdus Saleque, Shama Ishteak, Dhaka Sitting on a Sleeping Volcano, April 08, 2008,Bangladesh.

United Nations Environment Programme, State of the Environment: Bangladesh, United Nations Environment Programme, 2001.

 John Core, Consultant World Bank in Dhaka. Sources of air pollution and control options. Paper presented in the Consultative Meeting of World Bank and Department of Environment, Government of Bangladesh during April 26-27,1998 in Dhaka.

 BRTA (Bangladesh Road Transport Authority) (developed in Cooperation with DITS and BBS.

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