1. ASSESSMENT


    2. Air quality assessment includes an initial identification of pollution sources through monitoring and observation. This is followed by quantification of sources and monitoring of the most important pollutants. The aim of assessment is to provide relevant data in terms of spatial and temporal resolution.

    In Bangladesh wind flow changes its directions with seasons. The wind flow from different direction makes the country susceptible to transboundary air pollution. It is clearly stated earlier that country does not have any monitoring station in the boundary, not even operate existing divisional level monitoring station in a regular basis. Moreover, studies on effect of air pollution on human health and other ecosystem are very few. The following sections of the national action plan will give emphasis on developing of country and regional level assessment tools for integrated modeling of air pollution and its likely impact on human health and ecosystem. It is also be noted here that the assessment tools will be based on existing monitoring data and policy practices and will generate policy relevant information on various prevention and control options. From the baseline study, it is become clear that country needs a good baseline database on pollution concentration and emission at different point particularly urban and industrial zone as well as in the international boundary line. A rapid assessment can be done through integrating country and regional level experiences and knowledge on air pollution activities. The framework of the entire integrated air quality assessment and management tools is illustrated in Figure-3.1.

     

    1. ASSESSMENT TOOLS
DoE has developed several methodologies for assessing the impacts of developing activities on the environment. These are as follows:
    1. Ad-hoc
    2. Checklists
    3. Matrices
    4. Networks
    5. Overlays
    6. Environmental index using factor analysis
    7. Cost/benefit analysis and
    8. Simulation modeling workshop
Though need for more sophisticated method is felt by the authority, two of the above methods, viz. (ii) Checklist and (iii) Matrix are being practiced by DoE at present.

Note:

Checklists: Checklists are normative considerations evolved out of the examination of activity component relationships of the impact framework. Where qualitative or quantitative evaluations are attempted each impact area is associated with a list of environmental parameters, and the parameter data are measured to reflect the degree of impact.

Matrix: A matrix is a development of basic checklists, into a form of activity- component interaction. The matrix consists of a horizontal list of development activities displayed against a vertical list of environmental factors. The matrix is used to identify impacts by systematically checking each development activity against each environmental parameter.

Air quality assessment and management in terms of pollutant concentration and it likely impacts on human health and ecosystem is an emerging issue in the developing country. Future emission scenario, concentration and potential prevention/control options are also become imminent for managing quality of air. Like any other developing countries, Bangladesh does not have any integrated computer-based country or regional level air quality assessment and management tools which can be used for assessing impact and generate policy relevant information. A computer based integrated model is required to addressed the following issues.

 The air quality information will not only comprise sensitive and critical air pollutant data but will also address other information with respect to transboundary contribution and its distribution over the country and region. The assessment tools should have capabilities to incorporate various inputs as follows: The computer-based model can be developed combining the strength of Geographic Information System (GIS) for assessing impact of air pollution and its management in spatial context. GIS integration will allow the system not only to visualize the spatial distribution of pollutants and impacts but will also allow with some spatial analytical capabilities. Development and management tools require multidisciplinary expert inputs from different country of the South Asian region. A country and regional level team of expert can be formed in this regard incorporating experts from national focal point and collaborating center as well as expert from other government and non-government research organization. A tentative framework of the assessment tools can be presented schematically as of Figure-3.2.

Dispersion Models At the moment, there is no facility in Bangladesh to measure the dispersion of air pollutants. A dispersion modeling centre is needed to be set up in Dhaka to locate the transport of air pollutants to and from Bangladesh. Without dispersion model it will be difficult to assess the transboundary effects of air pollution. Air quality modeling will also provide the idea pollutant source strengths (i.e. emitted quantities per unit time) with meteorological data to estimate concentrations at the receptor point. So further study is needed to set up a dispersion modeling centre in Bangladesh.

Data required for dispersion models include the following:

Emission and source data:
 

 Wind and dispersion data: The proposed system for the dispersion module in Bangladesh is given in Figure 3.3. The input data required for emission dispersion calculations include data on meteorology, topography, emission characteristics of the sources, and data from the emissions module. Basic meteorological data are wind speed and direction presented as time series (hourly averages) or as climatological statistics (wind roses, annual or seasonal). Air temperature and its variation at different altitudes is also an important parameter. Topography and the presence of water bodies, land, or vegetation, influence wind and dispersion conditions and, in turn, pollution concentrations. Results from the dispersion calculations can be as detailed as the relevant input data,

Source: Jitendra J. Shah et al. (1997)
    1. ASSESSING IMPACTS
Areas of rapid urbanization and industrialization in the South Asian region are now starting experience of unacceptable air quality and projecting of rapid growth of vehicle populations. An average man inhales around 16 m3 of air per day and its quality is bound to be concern to him as well as all animals and vegetation that are not only inhale air but also totally immersed into it. Ambient air quality is also be of concern for prevention of structure and historical monuments that may be corroded or otherwise affected by the pollutants present in air. The environmental impact of air pollution is equally grave particularly impacts of acid rain on forests, crops and aquatic ecosystem.

This section will briefly describe the adverse impacts of air pollution on aquatic ecosystem, soil, groundwater and vegetation, historical places, human health, livestock and visibility with possible transboundary effects. It is also to be noted here that the impacts of air pollution on ecosystem are derived from various sources and develop an outline for future research requirement for this region.

Impact on Human Health

According to the world health organization health is a "state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. The air we breathe has not only life-supporting properties but also life damaging properties particularly when the balance among the air components is disturbed or otherwise become polluted. However, all the impurities in the inhaled air do not necessarily cause harm. The prime factors affecting human health are
    1. Nature of Pollutants
    2. Concentration of the Pollutants
    3. Duration of Exposure
    4. State of Health of receptor
    5. Age group of the receptor
The effect of air pollution on human health generally occurs as a result of contact between the pollutants and the body. Different pollutant has different effect on human health such as irritation occurs due to inhalation of sulphur dioxide which affects the mucous membrane, liver and kidney damage due to inorganic lead pollution. Based on the above mentioned factor impact of different pollutants on human health needed to assess against different development and abatement scenario.

Impacts on Livestock

Interest in the effects of air pollution on animals has generally developed as a corollary to the concern about its influence on human health. The process by which the livestock get poisoned is two steep process i) accumulation of the air borne contaminants in the vegetation and forage and ii) subsequent poisoning of the animals when they eat the contaminated vegetation and forage. The three main pollutants responsible for the most damages of livestock are fluorine, arsenic and lead

Impacts on Vegetation

Air pollution has long been known to have an adverse effect on plants. Number of air pollutants affect plants of which sulphur dioxide, nitrogen oxides and ammonia are common. Absorption of gas by the plants is primary depends on opening of stomata which again depends on light intensity, humidity, moisture supply to root and temperature. Therefore, pollution concentration and transboundary migration of pollutants is not enough for assessing the impacts. Moreover it requires an integrated approach combining seasonal variability of the weather.
 
 

 Impacts on Soil, Surface Water and Aquatic Ecosystem Condition of soil, surface water and aquatic ecosystem is interrelated. The health of aquatic ecosystem can be determined through assessing the richness of the aquatic biodiversity or assessing the physical parameters such as water quality. Deterioration of the health aquatic ecosystem occurs mainly due to industrial and agricultural waste. However, part of exhaust and tire ware, corroded building materials and local and long-range atmospheric deposition are finally accumulated in the land and aquatic ecosystem through surface water flow. There is also direct impact of air pollution on aquatic ecosystem through acid rain. Transportation of air pollutants occurs not only through wind movement but also by water flow. Therefore, regional level integrated assessment is required which can be accomplished through this regional initiative.

Development Stages and Future Research Required

Monitoring of urban air pollution is conducting by the Department of Environment, which will be strengthened through "Air Quality Management Programme". This will emphasis on monitoring of air quality and will introduce some abatement measures for reducing emission of pollutants. But basic research is required to create coefficients for assessing impact of air pollution on different aspects, which also help standardizing and thresholds limit of pollutants.

Guidelines of DoE to Assess Air Pollution

To assess the impacts of air pollution, DoE has some set guidelines, such as:

Impact Identification: compiling the list of impacts and identifying the sources.

Impact prediction: Prediction scientifically characterizes the cause and effects of impact and its secondary and synergistic consequence for the environment and local community. It is also important to consider the socio-cultural impact which the local community will feel most acutly in their everyday lives.

Evaluation: It determines whether the impacts are significant enough to warrant mitigation.

Mitigation Measures: A wide range of measures are available to prevent, reduce, remedy or compensate fro each of the adverse impacts evaluated as significant.

 3.3 ASSESSING PREVENTION/ABATEMENT OPTIONS Measures to prevent or control air pollution are straightforward because the major causes of air pollution are commonly known particularly for urban areas. Measures to prevent pollution from wood and other biomass burning for cooking and brick burning are relatively difficult due to its disperse nature. But whatever policy measures are to be recommended should be cost effective and socially acceptable. All pollution control and prevention measures should be evaluated under the following broad heading.
  1. Effectiveness both in terms of emission reduction and reduced impacts. Such as certain amount pollution reduction will reduce mortality, respiratory symptom, total health cost etc.,
  2. Costs of both technology and implementation,
  3. Financial Benefit both short term and long term,
  4. Policy instrument that might be used to implement measures.
Suggestions for some abatement options are as follows: Public awareness and education Preparing and implementing an effective air pollution control strategy requires awareness at all levels of society, including policymakers, implementing agencies, manufacturing and service industries, and the public. Education of policymakers is fundamental in developing an integrated air pollution control strategy that includes cost-effective measures to control vehicular and industrial emissions.

If measures to reduce air pollution are to be effective, the public must support them. Public participation through roundtables, seminars, and meetings enhances formulation of a sound package of measures and eases resistance to environmental protection by special interest group.

The following measures may be taken to reduce vehicular emission:

 Vehicle-Targeted Measures
    1. Setting emission standards and related measures for new vehicles,
    2. Engine modifications
    3. Introducing catalytic converters
    4. Roadside inspection programs
    5. Impose emission restriction on imported vehicles
    6. Introduce vehicle emission fees
Fuel-Targeted Measure
    1. Setting gasoline standard
    2. Encourage to use alternative fuel such as CNG
Transport Management Measures
    1. Road pricing and area licensing
    2. Encourage High Occupancy Vehicle (HOV)
    3. Setting staggered work hours
    1. REPORTING
The country should prepare an annual report with seasonal variation of the different pollutant’s concentration with their spatial distribution and impacts. As the DoE is the focal point and National Implementing Agency for the Male Declaration, the responsibility of reporting should be with them.

The report will provide information on:
    1. Model based pollution inventories with their spatial distribution. It will also address concentration and transboundary contribution
    2. Abatement potential of different measures and their benefit
    3. Impact analysis on human health, plants and animals, soil, surface water, aquatic ecosystem etc. with different control measures
    4. Limitation and future requirement
    5. Conclusion and recommendation