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ASSESSMENT
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Assessment Tools
Apart from the use of Gaussian plume models (ISCT2 and
Screen 3) for point source modelling as part of the EIA process, there
are no other large scale dispersion models that are being employed by any
involved agencies. The objective and the need is to develop dispersion
models that could (a) predict air quality in regions, (b) be able to calculate
concentrations using emissions from different groups including the transboundary
sources, and (c) provide input to policy makers and to predict the implications
of the different control strategies proposed in Section 4. With the use
of the monitoring network the model should be "tuned" to increase the accuracy
of the model. In the long-term, models should be integrated with the GIS
based spatial data to form a part of the integrated air quality management
system.
The proposed system for the air quality assessment
in Sri Lanka is as shown in the diagram 2 below.
Action Plan:
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Dispersion Model: CEA should develop a
time-dependent dispersion model such that the model could predict where
the puffs of pollutants are advancing along the wind trajectory and where
diffusion, transformation and deposition take place.
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Integration with GIS: The CEA should integrate
the model with GIS based spatial data and this to be fine-tuned with the
data obtained from the monitoring programme. This would help in making
policy decisions and simulate the impact of the various control and abatement
options proposed.
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Assessing Impact
It is evident from the acid rain monitoring data, that
some of the areas such as the hill country and the northcentral areas have
pH values <5.5 after a drought period is experienced. In the upcountry
areas of Sri Lanka tea is grown extensively, while in the low lying areas
paddy is grown extensively. Also, most of the country’s historical monuments
are located in the northcentral area. The impacts on these crops or the
monuments have not been studied to the depth that is needed to draw any
conclusions. Attempts have been made by medical professionals and academic
institutions to determine the adverse health impacts due to lead emissions
in the City of Colombo by checking blood samples from policemen and school
children. However, these efforts had to be discontinued due to the problem
of obtaining volunteer sample groups.
The objective of this section is to develop and use
models to determine the extent of exposure and damage to human health,
damage to the ecosystem, buildings and materials and finally to the place
an economic value on the negative impacts of air pollution.
Action plan:
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Damage assessment – population & assets:
The damage assessment should be done beginning in Colombo where the concentration
of air pollution is higher compared to the other cities. Also on crops
and monuments especially in the northcentral area due to the transportation
of the air pollutants from the cities and the transboundary movement from
the region. Based on the model to be developed and using monitoring data,
dose-response functions should be developed for Sri Lanka.
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Damage assessment – health: Impact on
health, especially in the urban areas, is a growing concern. In the short
term, it is suggested that epidemiological studies be correlated to the
variations in air pollution levels across spatial areas with incidences
of time series variations in mortality and morbidity in the Colombo City.
The outcome to be linked to monetary values due to health impacts.
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Air pollution exposure Measurement: To
assist the NBRO with the proposed personal sampling programme and expand
it to other cities in the island and also conduct sampling for indoor air
pollution exposure due to fuel wood burning.
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Air Quality Guidelines: Presently only
national ambient air quality standards are available and CEA needs to develop
or adopt a particular (eg. WHO) a guideline for acceptable air quality
for different "receptors" in Sri Lanka.
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Assessing Prevention/Abatement Options
The Clean Air 2000 Action Plan approved by the
cabinet of ministers in 1993 is the only air pollution abatement action
plan that is presently being used by the government. Besides this the EIA
and Environmental Licensing procedure are the other two abatement options
available for the regulatory authorities for control of air pollution from
stationary sources. The action plan was developed on the basis that each
of the actions has a positive impact on the net annual emissions. This
7 year action plan was based on some finite assumptions i.e. the impact
that the action would have on the emission loads by the year 2000 from
an estimated base value in 1990. Reduction in emission loads corresponding
to the pollutant for each of the principles is given in Annex 1. However,
there was no cost benefit or cost effective analysis that was performed
on the actions proposed. As part of Urban Development Authority’s "Environmental
Management Strategy for Colombo Urban Area (1993), a simple cost-benefit
analysis was performed. EIA regulation mandates a cost-benefit analysis
on the environmental mitigation options proposed.
Action Plan:
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Assessment of prevention/abatement options:
Based on the assumptions that are given in Annex 1, and reviewing the actions
already completed the present position should be assessed. The same procedure
to be used for all the future actions that is proposed by the M/F&E
and CEA.
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Cost Benefit Analysis: Cost benefit or
cost effective analysis should be conducted on the abatement and control
measures that are proposed under the section 4 of this report. The present
EIA guidelines to be used for this purpose.
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Reporting
The Ministry of Forestry and Environment (M/F&E),
that chairs the CA2AP Implementation Committee should form the main body
co-ordinating all monitoring and research programmes on air quality management.
As the CEA is the focal point and the National Implementation Agency for
the Malé Declaration, the responsibility of reporting should be
with them. However, the reports should be approved by the CA2AP Implementation
Committee so that there is consensus on the data and methods used for analysis.
Action Plan:
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Reporting: The CEA to develop a reporting format, protocol
and be the focal point for reporting.
Summary of the Action Plan to improve the present monitoring
network ,data dissemination and to standardise emission inventory is outlined
in Table 5 below:
Table 5: Summary of the Proposed Actions
|
Issue
|
Proposed Action
|
Institution Responsible
|
Approximate Cost – US$
|
| Dispersion
Model
|
-
To develop a time based dispersion model
|
CEA |
200,000 |
| Integration
with GIS |
-
To develop and integrate with the GIS
based spatial data
|
CEA |
100,000 |
| Training |
a. Training on dispersion modelling
and GIS
|
CEA |
100,000 |
| Damage Assessment |
-
Development of dose – response functions
for various receptors
|
CEA |
50,000 |
| Personal Exposure
Monitoring |
-
Assist the NBRO with the proposed programme
and expand to other cities
|
NBRO/CEA |
15,000/y |
| Air Quality
Guidelines |
-
Develop or adopt a air quality guidelines
|
CEA |
In house |
| Cost Benefit
Analysis |
-
Perform Cost Benefit analysis
|
M/F&E/CEA |
15,000 |
| Reporting |
-
To develop a reporting format and protocol
needs
|
M/F&E/CEA |
In house |