Muhammad MahadiEnvironmental 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.
The general principle of law is that all landowners along a watercourse have the same right to the use and enjoyment of its water, provided no one owner substantially climinishes or pollutes the stream, thereby causing hardship to downstream users. A landowner does not own the water in a stream. Nov 12, 2015 Living with unsafe water in Dhaka. Statistics from DWASA – mandated with the task of supplying safe water and disposing of domestic and industrial waste in the fast growing megacity — reveal that there are five water treatment plants with a capacity of 2.42 billion litres water a day against a demand of about 2.5 billion litres.
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. 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.
.Recent Searches. Dhaka ranks highly amongst the world’s major cities in terms of poor urban air quality. Substantially reducing air pollution could save up to 3,500 lives and avoid up to 230 million cases of respiratory diseases annually in Bangladesh. In economic terms, this is equivalent to around US$ 500 million in savings due to reduced health care costs and increased productivity per annum.
The is the first program of its kind to tackle pollution from two of the country’s biggest polluters, brickfields and transport. Through the ‘co-benefit’ approach for the environment and transport sectors, the project aims to strengthen the environmental agency’s capacity and capability to effectively address air pollution issues, as well as to ensure safe mobility for people in the capital.ChallengeBrickfields in expel over 9.8 million tons of greenhouse gases into the air annually due to a combination of old technology, weak environmental legislation and enforcement and lack of corporate responsibility. Meanwhile, growing numbers of motorized vehicles are clogging up roads and contributing further to poor air quality.
Besides the large number of cars, the ever-present conflict between motorized and non-motorized transport such as rickshaws means urban traffic is often brought to a standstill for long periods of times resulting in not only health and environmental damage but huge economic losses dues to lost time. What’s more, very few alternatives exist for pedestrians to walk from one place to another, exacerbating the situation further. Brick kilns and motor vehicles contribute to 60% of fine particulate pollution in Dhaka during dry season.ApproachCASE directly tackles pollution by encouraging the adoption of cleaner brick manufacturing technologies that require less energy such as New Zig Zag Kilns, Improved Zig-Zag Kiln, Vertical Shaft Brick Kiln, Mini Tunnel or Horizontal Shaft Brick Kiln, alternative building material and Tunnel Kiln. The program is launching 20 demonstration projects that will be a catalyst in the widespread adoption of cleaner and efficient technology by entrepreneurs motivated by both the economic and environmental benefits.
The project also encourages research into technology alternatives to bricks such as micro concrete, and helps the Government in strengthening environmental laws to introduce stricter standards and stronger “polluter pays” principles for industrial pollution. CASE also provides support to the newly established Air Quality Cell (AQC) that is responsible for air quality monitoring, data analysis and reporting and public information and administration.In urban transport, CASE is promoting safe pedestrian mobility in Dhaka by actively rehabilitating and improving 70km of sidewalk with surface drainage and constructing 23 foot over bridges. It is also improving traffic management by improving 40 intersections, installing traffic signals and training the police in the enforcement of traffic signalization. Under the CASE project the feasibility study of a 20 km Bus Rapid Transit (or BRT) line from the airport to Keraniganj has been completed, and the detail design is being prepared.
BRT offers a low cost high efficient solution to public transport in the congested city of Dhaka. In order to strengthen the coordination of urban transport projects and policies, the project gives technical assistance and capacity building to Dhaka Transport Coordination Authority (DTCA) to make it a pivotal institution in planning and coordination of urban transport.
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