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Clean Air Scorecard Air Quality Management Assessment

Clean Air Asia developed a comprehensive analysis tool for understanding the air quality management status in cities – the Clean Air Scorecard tool (CAST). CAST is an excel-based tool which incorporates three indices: (i) Air Pollution and Health, (ii) Clean Air Management Capacity, and (iii) Clean Air Policies and Actions, which taken together give the AQM status of a city.


  • Air Pollution and Health Index: Critical
  • City Air Management Capacity: Limited
  • Clean Air Policies and actions: Moderate
  • Overall Score: Developing

Stakeholder Consultation for Guwahati Air Action Plan (April 2017)

A  multi-stakeholder consultation was conducted in April to bring comprehensive knowledge, expertise and technical solutions to relevant stakeholders to tackle air pollution in the city of Guwahti. The consultation was attended by the Commissioner of Transport, Government of Assam, members of the Assam Pollution Control Board (APCB), Guwahati Municipal Corporation (GMC), Guwahati Metropolitan Development Authority (GMDA), IIT Guwahati, Assam Science Technology and Environment Council (ASTEC), Guwahti University, members of the media, health practitioners and others. The consultation was divided into three panels:

(i) Panel 1: Air Quality Issues in Guwahati: Vehicles, roadside dust, hill cutting and waste management.

(ii) Panel 2: Air Quality Management in Guwahati: Current Scenario and Future Steps

(iii) Panel 3: Air Pollution and Quality of Life in Guwahati.

Capacity Building Workshop for Air Action Plan for Guwahati City (January 2018)

A two day workshop was jointly organized by Clean Air Asia and Guwahati Municipal Corporation on 9th & 10th January 2018. The workshop was attended by 40 city officials to deliberate on the needs of the city and steps to be taken to draft a clean air action plan for the city. The workshop consisted of technical sessions and brainstorming exercises through a deliberation process with city officials. The technical sessions in the workshop were, Air Quality in Guwahati – aspects and issues; air quality monitoring, management and data dissemination; trends of air quality in Guwahati city based on city specific studies; air quality and health effects and communicating impacts and the process of drafting an air action plan for the city.

Guidance Framework

Is a Framework prepared through a series of consultations by the United Nations Environment Programme (UNEP) and Clean Air Asia was developed to provide guidance in implementing the long-term vision for urban air quality in Asia.

A. Air Action Plan

  • Assam Pollution Control Board submitted its Clean Air Action Plan to the Central Pollution Control Board.

Air Action Plan are set of measures and initiatives that the State Governments and Departments along with the inclusion of NGOs and CSOs undertake to provide a clean and healthy environment to the citizens as envisaged in the Constitution of India.

Action Plan has laid down short- term and long-term plans for tackling pollution in the city. Under various had such as tackling vehicle emission, industrial pollution there mix of short – term and long – term plans. They are plans to mitigate resuspension of dust, road design improvement, burning of open waste, construction, and demolition activities etc.


B. Monitoring Network of the city

  • Guwahati city has one monitor under the National Air Monitoring maintained by Central Pollution Control Board which has been established at Bamunimaidam. A few numbers of monitoring stations under this program has been proposed to be established.


C. Government Policies, Acts, Laws, Press Release – Central Act and Policies, State Acts and Policies. Press Release on steps which will have impact on Air Pollution.


1.Central Acts

  • Air (Prevention and Control of Pollution) Act, 1981, amended 1987,

It is the Principal Act enacted in pursuance of the Stockholm Declaration, 1972 for prevention, control, and abatement of Air Pollution. They were amended in 1987 giving the Pollution Control Boards more authority and power.


  • Air (Prevention and Control of Pollution) Rules, 1982

Rules were enacted to support the Principal Act in better management and control of Air Pollution


2. State Act

  • The Air (Prevention and Control of Pollution) Assam Rules, 1991

Most states formulated Air (Prevention and Control of Pollution) Rules which deal with meetings of the Board and its committees, power and duties of the Member-Secretary and appointment of employees, power and functions of the Board, the State Air Laboratory, the procedure to deal with appeals and the budget.


D.State and National Set Standards

  • National Ambient Air Quality Standards, 2009.

Ambient air quality refers to the condition or quality of air surrounding us in the outdoors. National Ambient Air Quality Standards are the standards for ambient air quality set by Central Pollution Control board (CPCB) that is applicable nationwide. The CPCB has been conferred this power by the Air (Prevention and Control of Pollution) Act, 1981.

A. Source Apportionment Study 

Scholar Researches

  • Assessment of PM5 and PM10 over Guwahati in Brahmaputra River Valley: Temporal evolution, source apportionment and meteorological dependence, Atmospheric Pollution Research, Volume 8, Issue 1, January 2017 – S.Tiwari, U.C.Dumka, A.S.Gautam, D.G. Kaskaoutis, A.K. Srivastava, D.S. Bisht, R.K. Chakrabarty, B.J.Sumlin and F. Solomon

Temporal evolution, source apportionment and transport pathways of particulate matter (PM2.5 and PM10) are analysed over Guwahati, located in the Brahmaputra River Valley (BRV), as a function of meteorological dynamics. Analysis reveals that the local emissions, transported aerosols, along with seasonally-changed air masses, meteorology and boundary-layer dynamics control the concentrations, evolution, and fractions of PM over BRV. The turbid air masses transported over Guwahati mostly from western and southwestern directions contribute to higher PM concentrations, either carrying anthropogenic pollution from Indo-Gangetic Plains or locally and LRT dust from BRV and western India, respectively.



  • Urban Emission under its Air Pollution Knowledge and Assessment Program, conducted source apportionment study of Guwahati City. According to the study the major contributor to air pollution in the city is the Transport emission contributing to 35%, followed by dust emission 32%.


B.Pervious Year Trend

  • Assam Pollution Control Board has uploaded there monthly air quality index from July 2015 to February 2020.

A. City-specific studies

  • Influence of anthropogenic emissions on wet deposition of pollutants and rainwater acidity in Guwahati, a UNSECO heritage city in Northeast India, Atmospheric Research, Volume 232, February 2020 – Rajyalakshmi Garaga, Supriyo Chakraborty, Hongliang Zhang, Sharad Gokhale, Qiao Xue, Sri Harsha Kota.

Guwahati, the largest urban corridor of Northeast India, is one of the United Nations Educational, Scientific and Cultural Organization (UNESCO) world heritage sites and one of the 200 eco-regions in the world. The present study investigates the characterization of chemical components and sources of precipitation samples collected in Guwahati during June 2016–June 2017. he Positive Matrix Factorization (PMF) along with isotope analysis identified marine (40%) as the major source in monsoon and industrial emissions (28%) in non-monsoon, indicating rainwater evaporation is more of ocean and continental origin during monsoon and non-monsoons, respectively. This study suggests the need of further studies and implementation of stringent anthropogenic regulations not only in local but also at regional and global scale, in this acid rain prone region.


  • An Assessment of air pollution tolerance indices of some plant species grown in and around an industrial area in Guwahati, Assam, India, Journal of Engineering Research and Application, October 2018 – Manipuspak Hazarika, Dr. S. Sureshkumar Singh, Dr. Ajay Bharti

Air pollution tolerance index (APTI) of 24 plant species growing in a waste metal recycling industrial estate at Boragaon, Guwahati, Assam were determined for a period of 6 months by evaluating the relative water content, leaf extracts pH, total chlorophyll content and ascorbic acid content. The result indicates that different plants exhibit varying levels of tolerance and sensitivity to three major air pollutants (PM10, SO2 and NOx). In the study, it was observed that highest values of APTI and ascorbic acid contents were recorded only in two plant species, Catharanthus roseus and Melia azedarach revealing the tolerant capacities of these plants to sustain their growth and survival in polluted environment as compared to other plant species.

Click here read complete Report.


  • Seasonal Variation of airborne allergenic fungal spores in ambient PM10 – a study in Guwahati, the largest city of north-east India, Air Quality, Atmosphere and Health, September 2018 – Rajyalakshmi Garga, C.K.R. Avinash and Sri Harsha Kota

Fungal spores in ambient particulate matter (PM) is one of the major constituents which can adversely affect human health. For the first time, an investigation was conducted for 1 year at a residential region in north-east India to study the seasonal variation of PM10-associated fungal spore concentration and their diversity. Seven individual genera of fungal spores, namely Aspergillus, Penicillium, Cladosporium, Fusarium, Curvularia, Rhizopus, and Non-sporing isolates, were identified. Strong correlations between the Cladosporium and Penicillium and Cladosporium and Aspergillus were observed, which are well-known asthma allergens. Fungal spore concentrations peaked during summer and were least during monsoon.


  • Street Dust bound PAHs, carbon, and heavy metals in Guwahati city – Seasonality, toxicity and sources, Sustainable Cities and Society, Volume 19, December 2015 – Karishma Hussain, Mirzanur Rahman, Amit Prakash and Raza Rafiqul Hoque

Street dust is an indicator of pollution status of a city area. We present comprehensive assessment of USEPA’s priority 16 Polycyclic Aromatic Hydrocarbons (PAHs), carbon and heavy metals in street dust of Guwahati, a fast growing city of the Brahmaputra Valley. On assessment of different representative landuse classes, the concentrations of PAHs were found to decrease spatially in the order of industrial, commercial, institutional, residential and forest site. The profile of PAHs was dominated by 2- and 4-ring compounds and the carcinogenic PAHs (CPAHs) were found to be in the range of 16–55% of ∑PAHs. The mean toxicity in terms of Benzo(a)pyrene equivalent (BaPq) concentrations varied seasonally, which was found to be maximum during pre-monsoon. Principal Component Analysis, diagnostic ratios and correlations of PAHs with heavy metal implied that the PAHs originated mainly from coal and wood burning, and vehicular emission. Seasonality in sources of PAHs with respect to the diagnostic ratios was discovered and signatory influence of local sources was found during the pre-monsoon. The correlations of black carbon (BC) and organic carbon (OC) with PAHs were found to show seasonality.


  • Assessment of urban air quality in Guwahati City, India using air quality index, International Journal of Multidisciplinary Research, October 2014 – Bhuyan Bhuyan and Rupali Gupta

Pollution of the air is one of the primary problems in Indian cities. Various studies in recent time have put Guwahati among the most polluted city not only in India but in the world. The analysis of the ambient air quality data from 2004 till 2010 shows that the Respirable Suspended Particulate Matter (RSPM) and Suspended Particulate Matter (SPM) in almost all the monitoring stations in Guwahati is alarmingly high, beyond the prescribed standards set by the National Ambient Air Quality Monitoring Program in India. The Air Quality Index for Guwahati falls under the very unhealthy category wherein, the general public is at greater risk and the groups are at greatest risk. An increase in vehicular pollution is the primary causes of air pollution in Guwahati along with dust pollution and exhaust from the brick kiln industries.


News articles


  • Dusty winds, Forest blooming responsible for Guwahati’s Poor air quality during lockdown, 6th April 2020, Guwahati Plus


  • 88 cities continue to record minimal air pollution with lockdown in place, 31st March, 2020, Outlook


  • Covid – 19: Lockdown purifies cities of noxious city air, 27th March, 2020, Business Line


  • Assam to lead way in countering air pollution countrywide, 9th November, 2019, Guwahati Plus


  • Post Diwali, air quality degrades in Guwahati; SC Order on cracker bursting violated, 2nd November 2019, Guwahati Plus


  • Two days after Diwali, air quality turns ‘hazardous’ in Guwahati, 30th October, 2019, The Times of India


  • Guwahati rainwater being affected by natural and man-made air pollutants, new study reveals, 27th October, 2019, Firstpost


  • Natural, man-made air pollutants tinkering with Guwahati’s rainwater, 22nd October, 2019


  • Here is why it’s high time for Guwahatians to celebrate ‘Green Diwali’, 19th October, 2019, Guwahati Plus


  • IIT Guwahati to offer technical assistance to curb pollution in Assam,5th October, 2019, The Times of India


  • IIT Guwahati & pollution control board to tackle air pollution in Assam, 4th October, 2019, The Economic Times


  • Guwahati breathes better as air quality improves, says PCBA, 20th June, 2019, Guwahati Plus


  • Air pollution wreaking havoc in Northeast states: Study, 6th June, 2019, Times of India


  • PCBA monitors show Guwahati air as most polluted between 6PM to 8PM, 9th December, 2018, Guwahati Plus


  • Air Pollution all-time high in Guwahati City, 8th December, 2018, The Sentinel


  • Air Quality in Guwahati within ‘satisfactory’ limits: Pollution board, 26th November, 2017


A. Communication Portal for local government

  • Grievance Redressal Portal – The Pollution Control Board Assam has designated a Public Grievance Officer and provided the details on their website.

A. CAST Study 

Clean Air Asia has developed a Clean Air Scorecard Tool, which is an Excel-based tool understanding the Air Quality Management of the cities. There are three indices

  1. Air Pollution and Health
  2. Clean Air Management Capacity
  • Clean Air Policies and Action

Clean Air Asia, India has done CAST Study for 30 cities till now and counting. Guwahati was one of the first cities for which CAST Study was undertaken.

According to the Scorecard Tool the Over All Clean Air Score for Guwahati stands at 32.1 which comes under the category of Developing. One of the main areas which needs immediate attention is the Health Index and Air Quality.

B.Technical Knowledge Sharing

A. Way Forward 

B. Tool Kit