Tuesday, July 7, 2009

Air Pollution in Mumbai and people’s perception


Chatrapati Shivaji Terminus, formerly Victoria Terminus, in Mumbai. Photo by thebigdurian on Flickr.

I love Mumbai’s air..though it is very polluted as everyone says. At places, the air brings the smell of sea or wafting smell of lovely roadside food, at other places of leather, ammonia, garbage and stench of human filth. Now, all we seem to breathe in Mumbai is unbearable amounts of toxic gas mix all over Mumbai. Mumbai’s coastal climate is ideal for removal of air pollutants, however, the rate of removal is slower than the rate at which pollutants are generated, hence we end up with a cauldron of toxic gas mix.

Air pollution has a telling effect on the citizens of the city I love. My neighbour’s 5 year old son in Nerul, Navi Mumbai suffers from all sorts of respiratory problems. This is not however an isolated case. Scores of people, especially from the vulnerable group – children, women and old people - are affected. The effect of polluted air on human health is well known. This translates to persondays lost in as people fall sick more often – which in turn – means loss of revenue. The commercial capital of the country must not tolerate this loss. So it should take a cue from how the capital Delhi has dealt with air pollution.

As with everything else that citizens of Mumbai put up with, from terrorism to packed trains, heavily polluted air is also another in their list of things that they have come to accept. Very complacent huh? or are the people of Mumbai sitting ducks?


Sitting ducks, photograph by Purushottam V.Rao

How bad is the pollution on Mumbai? The city authorities are well aware of what it could loose if it fails to address this pressing issue of air pollution. It is engaged in various ameliorative measures to address the issue. What remains to be seen is whether these measures are yielding any positive results.

For the uninitiated, the common air pollutants are :

Carbon Monoxide - CO

Oxides of Nitrogen - NOx

Sulphur Dioxide - SO2

Suspended particular matter - SPM

Respirable suspended particulate matter - RSPM

Hydrocarbons – HC

Deteriorating air quality is the result of rapid economic growth, industrial output, unprecedented rise in vehicles to cater to the city’s burgeoning population.

As per World Bank report 1997 - “In Mumbai (Bombay) the main contributor of air pollution is the transport sector, followed by power plants, industrial units and burning of garbage. Fuel quality and engine conditions significantly influence the level of air pollution To arrest this growing problem, a concerted effort with public involvement is essential. Awareness of the issue, proactive policies, economically affordable standards and technologies and effective enforcement are key elements in any effective air quality management strategy A long- term perspective shows that early adoption of policies for environmentally safer technologies can allow developing countries to resolve some of the most difficult problems of industrialization and growth at lower human and economic cost.”

Ameliorative measures by city admin mainly focus on the vehicular pollution :

1) The bus and rail network in Mumbai is by far the best
public transportation infrastructure in the country in terms
of coverage, carrying capacity, and utilization. Moreover,
Mumbai is implementing an MRTS – metropolitan railway transit system.

2) In the spring of 2002 the High Court issued an order
that all the diesel taxis in the city change to using compressed natural gas [CNG]. They were allowed a few months to do so. Infrastructure was hastily set up to allow for this transition. Now all taxis which ply in Mumbai are either CNG or petrol.

3) The strengthening of the cities arterial roads and introduction of 55 flyovers for smoother flow of traffic in and out of the city.

These results of these measure show a steady decline in SO2 and RSPM concentrations in Mumbai. NOx concentrations are below the NAAQS standards and have remained steady. Monitoring results are available on Maharashtra State Pollution Control Board website.

However, SPM remains above NAAQS in Mumbai. A comprehensive emission inventory was conducted in 1997 for Mumbai as part of the Urban Air Quality Management Strategy (URBAIR). It was found in the study that the total suspended particulates exposure was primarily due to resuspension from roads caused by vehicles(40%), emission from diesel and gasoline vehicles (14%), domestic wood and refuse burning (31%), and others (15%) (World Bank 1997). The aspect of resuspension formed one of the important areas of investigation in the later emission inventory-related studies.

And people’s perception of high air pollution is due to these levels of suspended particulate matter. The World Bank conducted a public perception survey in 2004. One purpose of the survey was to compare the perceptions of stakeholders to the findings of the recent analyses of air quality trends and sources of particulate air pollution in Indian cities. The survey was not designed to yield statistically significant results. It was rather a modest attempt to get a broad picture of the perceptions and understandings of informed observers of urban air pollution in India. “Nearly half of the respondents said
that air quality in their cities was deteriorating. Transport was
considered the most important cause of air pollution.” Country Synthesis report on Urban air Quality,Dec 2006.

I get to hear this from a lot of people who travel from the west to Mumbai and get stuck in the city’s maze of taxi’s and three wheelers – unable to bear the pollution or the heat of the city – they come back and say that ‘Oh my God, Mumbai is so polluted’. One must take a leaf out of the former mayor of London – who decided to take the local train during his stay in Mumbai (just to get a feel of it - I suppose!). Either the monitoring done in the city is at wrong locations – hence showing decreasing trend in pollutant concentrations or the people have wrong perceptions regarding the changing air quality of city of Mumbai!!

People’s perception has a lot to do with air quality battles – rather than depending on the city admin to change the air quality – and avoid being sitting ducks – the citizens of Mumbai must participate actively in the following through proactive groups:

1. Refuse burning – form area active groups to prevent refuse burning

2. Construction activities – ensure builders in your area comply with mitigation measures for air pollution – a construction phase of a project is a temporary phase and hence many builders do not employ any mitigation measures for air pollution reduction. A year of construction activity may result in a year of misery in a child or senior citizens life.

3. Diesel generators generate a lot of SPM and SO2 – many of these generators can be seen at construction sites – it is the duty of the citizen to form an action group – to ensure DG sets comply with current emission norms(Refer CPCB websites on DG set emission norms).

4. Use public transport – leave personal vehicles at home.

5. Service your vehicle and keep your pollution under control certificate up to date.

6. Spot out vehicles using adulterated fuel – and report to state police.

The CPCB website gives a list of dos and donts for the citizens for reducing vehicular pollution.

The latest environmental status report is available at http://mpcb.gov.in/images/pdf/envreportmumbai.pdf.

Taking a cue from the cities of Pune, Delhi and Hyderabad, the citizens of Mumbai - could ask for digital signboards indicating the air pollutant concentrations for each day.

Don’t be sitting ducks – be proactive – breathe cleaner air!


  1. Dear Sunita,

    That's quite an interesting article you have posted there. I find it amusing that you have listed improvement of roads & flyovers in the city as an ameliorating measure. If anything, improved roads will lead to increased private vehicle ownership. We need the State to step-up the execution of BRTS & MRTS, something which it is loath to do. Well written post. I agree with most of the points that you have stated!

  2. Thanks Govind,

    Yes the state seems to think so..a disproportionate amount of money has been siphoned off to improve road infrastructure - and there has been an increase in private vehicle ownership - what a flyover does is to allow smooth traffic flow and hence does have AQ benefit..but this is offset by increasing vehicular traffic. The other measures like encouraging vehicles like Reva and congestion charging must go in tandem with improved infrastructure..also the fact that city development authorities have completely overlooked the needs of the pedestrian - the most environmentally friendly transport system...a separate blog on this pet peeve of mine - that the city is no longer walkable..

  3. Hi Sunita,

    Nice article and a touchy subject you touched upon this time. Mumbai Master plan and a lot of other initiated ongoing infrastructure projects reveal that Mumbai is way behind in the development yet. No wonder, being several years behind your infrastructure targets, the current roads and railways are overburdened with traffic, and hence pollution.

  4. Hi Sunita,

    Well written article. I thought the flyover or by-pass was a good idea for moving vehicles around the city rather than entering the city. There may be a possible increase in vehhicles but is the rate of vehicles not always climbing? This handles the increase already going on.

  5. Thanks for the encouraging comments.

    Right - delay in infrastructure projects intended to handle increasing traffic loads do lead to congestion and air pollution.

    Vehicle ownership rates are rising steadily at a rate of 7 tp 9 % per year in most urban areas in India.

  6. Sunita:
    Interesting post. I just looked up MSPCB's website, and it looks like they just monitor NOx, SO2 and SPM/RSPM. The "standard" for SPM seems different for different locations within the city! There doesn't seem to be any ozone monitoring either.

    I am glad you listed refuse burning and construction activity - one reason I dislike going back to Mumbai (I grew up in Matunga) is because of the constant construction activity. Grinding/cutting all those marble/granite slabs in the open releases a lot of dust that affects everybody in the vicinity (and contributes to the road-dust that is re-suspended by vehicles.)

    One must also keep in mind the size distribution of PM while trying to reduce it. Vehicle emissions tend to be at the small sizes, so they may not contribute much to mass (RSPM could be PM10, while vehicle emissions tend to be PM2.5 and even PM1.) FYI, I just saw a presentation by Suresh Dhaniyala of Clarkson U that showed rural cookstove PM emissions are smaller than 300 nm - so DustTraks and other similar devices tend to underestimate PM mass as the lower size limit of these common instruments is (apparently) about 200 nm. On the other hand, some of the construction debris is likely too big to enter the lungs, though they might affect the nasal passage/respiratory tract...

    A complex issue... Guess that's why they pay us the big bucks to study it! [What big bucks? :-)]

  7. thanks RS for your comments - yes a complex issue no doubt! The different standards for different locations is due to the classification of locations as residential, industrial and commercial - a classification I feel is redundant..as if lives of people working in industrial zones is less valuable than those in residential areas!

  8. I am posting this comment on behalf of Jitu Shah from World Bank.

    Hi: I love your blog for many reasons. I am from Bombay - Mumbai, I love the city and also because you have referenced the World Bank report for which I was responsible so if there is anything wrong, I take the blame. Most of the comments that you and others have are right. But the question is, how come in spite of such extensive train and bus services, the air quality is still so bad. I can list many things that are wrong but only if you can enforcement to reduce the highly polluting trucks, interstate buses, two stroke three wheelers, and other obvious transport and high polluting activities (garbage burning is one),
    you will see a great deal of improvement. These very small numbers of the vehicles contribute to majority of the pollution (an educated guess). Unfortunately, this is not doable by the authorities for many reasons. Make it a political campaign issue and you may see improvement? I don?t live there anymore
    but when I do come for a visit, I am shocked by another BIG issue - lack of footpath for walking. Maybe you will write about that someday. Jitu Shah

  9. Another comment by my Italian friend Guiliano Gianforte
    Very interesting post - makes me feel like wanting to do something to improve the situation e.g. implement an action plan for Mumbai, which takes into account local conditions, but also meaures implemented
    elsewhere, e.g. London and mistakes not to be repeated in Mumbai. It seems though a signficant reduction in emissions (>30%!) would come from effective waste management."

  10. I have heard that Mumbai is a wonderful city where people are very friendly!

  11. Hi Sunita
    very interesting peice I found this peice when I was helping my daugther with her school project on Air Pollution this peice has been very helpful for her school work for that thanks I am a mumbaite living in the Gulf for some time and I agree with you when we do not do anything we are sitting ducks


I would be interested to know your views on this blog.