The World Environment Day takes place on June 5. The celebration of the day provides us with an opportunity to broaden the basis for an enlightened opinion and responsible conduct by individuals, enterprises and communities in preserving and enhancing the environment.The theme for 2019 is ‘Beat Air Pollution.’
This year’s topic invites us all to consider how we can change our everyday lives to reduce the amount of air pollution we produce, and prevent its contribution to global warming and its effects on our own health.
The environmental problems such as biodiversity loss, ecosystem degradation, landscape destruction, environmental pollution, climate change and urban heat islands are already exist in Indian cities and have a great stress upon the natural and built environment.
Over exploitation of open spaces, ever-increasing number of automobiles and demographic pressure have further aggravated the problem. The cities have failed to maintain the air-quality standards set by the Central Pollution Control Board (CPCB).
To manage the urban areas in a sustainable manner the Indian Government created the Smart City Mission and plans to create 100 new smart cities to support the country’s rapidly growing urban population. When announcing its plans in 2015, the Indian Government supposed that this type of development would be sustainable, environmentally friendly and smart.
The concept of smart cities is deemed to be one such solution for the sustainable urban development of future cities.
Six cities of Odisha (Cuttack, Bhubaneswar, Baleswar, Angul, Talcher and Rourkela), have failed to maintain the national ambient air quality standards fixed by the Central Pollution Control Board.
The different sources of air pollution in Bhubaneswar are small-scale industries, motor vehicles, etc. Vehicles account for 40 per cent of air pollution in Bhubaneswar. Besides, the level of pollution in the city has increased due to the increasing traffic and decrease in green cover.
A report by the Odisha State Pollution Control Board (OSPCB) revealed that pollutants in the ambient air were found to be far above the permissible limit at all the six pollution monitoring stations in Bhubaneswar, such as at Patrapada, IRC Village, the OSPCB office, the Capital police station, Rasulgarh and at the OSPCB laboratory in Chandrasekharpur.
Besides, air-pollution display board has been installed by the PCB at Power House Square. The board displays the air quality index of selected areas of the city. The board collates weekly data on air pollution from monitoring stations to determine the pollution levels.
The level of Particulate Matter (PM-10) in the air is between 120 to 213 microgram per metre cube in the city while the permissible limit is 100 micro gram per metre cube.
Air quality monitoring requires proper selection of pollutants, selection of locations, frequency and duration of sampling, sampling techniques, infrastructural facilities. The locations selected for monitoring are based on high traffic density, industrial growth, human population and its distribution etc. Increased number of vehicles in the city results in more vehicular emission leading to high air pollution.
A variety of pollutants are emitted by petrol and diesel driven-engine motor vehicles. These include carbon monoxide, oxides of nitrogen, volatile organic compounds (VOCs) and particulate matters (PM10 and PM2.5).
Large construction activities in urban areas are rapidly destroying green areas in the city. Extensive green cover helps to maintain pollutant concentrations within permissible limits. The recent Smart City initiative by the Indian Government promoting development of urban green spaces can be coupled with strategic landscaping to optimise benefits of greening programmes. Presence of greenbelts around islands of pollution such as industrial zones reduces spread of pollutants.
There is a need to study optimum green space to be provided per capita in a city from different standards and codes. This may be applied for smart city planning process.
There are various ways and means to mitigate the urban environmental pollution. Planting of trees and shrubs for abatement of pollution and improvement of environment is an effective way and well recognized.
Roads are the important sites of the urban areas which contribute significantly in generating pollution. By planting trees on both sides of the road pollution can be mitigated. However, during tree plantation in an urban environment little or no attention has been paid to evaluate the effect of trees on filtering pollutants.
With an aspiration to become an environmentally smart and sustainable city, the Bhubaneswar Municipal Corporation (BMC), proposed a pan-city “Smart Solution” project that includes environmental monitoring systems comprising various sensors and communication technologies for comprehensive monitoring.
The Bhubaneswar Smart City Limited has started implementing the air action plan to curb air pollution in the city. Some of the green field developments have also been conceptualized for smart city planning.
Under the green field development new areas (greenfield) will be developed around cities in order to accommodate the expanding population in urban areas. Greenfield development will introduce most of the smart solutions in a previously vacant area (more than 250 acres) using innovative planning.
Greenfield developments are required around cities in order to address the needs of the expanding population. Unlike retrofitting and redevelopment, greenfield developments could be located either within the limits of the ULB or within the limits of the local urban development authority.
It has been scientifically proven through research that trees absorb pollutants. Therefore, there is a need to prepare plantation details with list of the trees which can be planted to absorb specific pollutants present at various locations in the city. In Smart City Bhubaneswar, air pollution can be reduced effectively by using more green space in the city planning process.
Besides, urban green space is important in providing several ecosystem services. Green cover helps in climate change mitigation and pollution abatement besides helping in conservation of ecosystem and biodiversity.
Urban vegetation can directly and indirectly affect local and regional air quality by altering the urban atmospheric environment. There are a number of native trees which can trap pollutants in the city. Their leaf structures help to trap more dust and other pollutants.
Besides, the ways in which trees affect air quality are temperature reduction and other microclimatic effects.
While selecting the species for pollution control, the important characteristics of the plants should be considered for pollution control and prevention.
There is a need to study the native plant species with high absorption of pollutants. Air pollution tolerance index (APTI) may be used to select plant species tolerant to air pollution. Besides, the pollution from motor vehicles can be minimised by using new as well as innovative technology and alternate fuels.
The presence of air pollutants above the prescribed limit in the ambient air adversely affects the environment including health of the human being. In order to prevent and control air pollution, the Union Govt. enacted the Air (Prevention and Control of Pollution) Act in 1981.
Environment (Protection) Act, 1986, necessitate to address the pollution problem through air quality survey/monitoring programs. Various environmental standards, specifications and guidelines of Central Pollution Control Board may also be applicable in the smart city planning process to prevent air pollution.
(Dr Praharaj teaches at Department of Architecture, College of Engineering and Technology, Bhubaneswar)