#14.1 - Priyanka Kulshreshtha: On the Frontlines of India's Indoor Air Quality Revolution

Part 1

Priyanka Kulshreshtha -  is a founding member and Secretary of the Society of Indoor Environment (SIE), a policy think tank for issues related to indoor environmental quality in India.  She is an Assistant Professor at the University of Delhi.

She has been on the editorial board of prominent international journals, including the  Journal of Health and Pollution, Sustainability in Environment, Air Quality, Atmosphere and Health, Environmental Research, to name just a few.

She has been the Editor of SIE's quarterly newsletter, “THE INDOORS “, since 2019.

She has experience working on the European Union Project “HEALTH EVENT” and has, to her credit, more than 30 publications in international journals, articles, and conference papers.

A visiting faculty at the International Centre for Environmental Audit and Sustainable
Development and has also worked with policymakers in India regarding
formulation and scoping of IAQ guidelines.

With two decades in the field of indoor air quality management. Her core domain of work is research on Indoor Air Quality and its exposure assessment. Priyanka is a fascinating window into the field of air quality in India right now, where it has come from and where it may be heading.

She is at the heart of an exciting yet challenging environment, with so much at stake and potential. You really get the sense talking to Priyanka that things are on the move in India, and there is a generation of bright and committed researchers, policymakers, and industry professionals making waves.

We had a great conversation about the particular challenges of air quality in Dehli and other parts of the country, her work around homes, schools, the workplace, standards and where all this might be going.

Priyanka Kulshreshtha - LinkedIn

Society of Indoor Environment (SIE)

Indian Insititute of Sustainable Development 

Transcript

Simon: 0:14

Welcome to Air Quality Matters, and this is a conversation with Priyanka Kultretha. She is the founding member and secretary of the Society of Indoor Environment, a policy think tank for issues relating to indoor environmental quality in India, and she is an assistant professor at the University of Delhi. She has been on the editorial board of prominent international journals, including the Journal of Health and Pollution, sustainability in Environment, air Quality, atmosphere and Health and Environmental Research, to name just a few. She has been the editor for the Society of Indoor Environment's quarterly newsletter, the Indoors, since 2019, and she has the experience of working in the European Union Project Health Vent and has, to her credit, more than 30 publications in international journals, articles and conference papers, a visiting faculty at the International Centre for Environmental Audit and Sustainable Development, and has also worked with policy makers in India regarding formulation and scoping of indoor air quality guidelines.

Simon: 1:31

With two decades in the field of indoor air quality management, with her core domain of work in research on indoor air quality and its exposure assessment, priyanka is a fascinating window into the field of air quality in India right now, where it has come from and where it may be heading.

Simon: 1:50

She is at the heart of an exciting yet challenging environment with so much at stake and so much potential. You really get the sense, talking to Priyanka, that things are on the move in India and there is a generation of bright and committed researchers, policy makers and industry professionals making waves. We had a really great conversation about the particular challenges of air quality in Delhi and other parts of the country, her work in the area around schools and the workplace standards and where this all might be going. As always, thanks for listening. This is a conversation with Priyanka Kral Shretha and I am very conscious when I say India is a huge continent and can be vastly different from one area to the other. So we should touch on that as well, that we are being quite generic when we are talking about India, but obviously it is a bit like saying America. There is a huge difference.

Priyanka: 2:54

That plays a very important role when we talk about research on air pollution. I think that is where we struggle to understand the dynamics. It is like in India we talk about Indo-Gangetic plane, so that is an area in the north wherein the pollution levels are supposedly the most during October to January, the reason being the wind condition, the temperature drop, the low mixing height of pollutants inside, and we are in that belt when I am talking about Indo-Gangetic plane. So it starts from Punjab, delhi goes to Banaras, so these are places which the cities which are there in this Indo-Gangetic planes. They have the maximum pollution levels during the winters, specifically supported by the meteorological conditions and some activities like stubble burning. Now this happens in Punjab. Punjab is first to the top of the northern area of India and the westerly winds blow and they bring that stubble smoke to Delhi and the nearby areas. That is one of the reasons that we are seeing lot of pollution levels increase during the October-November month. So it is a concoctious mixture. I would say it is a cocktail. That happens and sadly, because it deteriorates the quality of air in and around Delhi and also in the Indo-Gangetic plane. So it is just that Delhi is the capital of India, so it is highlighted more. But, as we know, in air does not have any boundaries, whether in Delhi or in the suburbs or nearby cities. But, having said that, where Delhi loses control is that it is a landlocked city, so anything which comes inside in Delhi stays there for longer in terms of pollutants. So if smoke stubble burning smoke is coming in, it will be there for a while. We have our own sources, vehicular sources, the industries, everything is there. But with the temperature drop that happens during October-November time, the cold air settles down, bringing it with it the pollutants closer to the earth surface and thereby very zero velocity wind that stagnates the whole condition. That is why, when I say Delhi is a landlocked city, I mean that it is landlocked. Something which comes there stays there, so that, combined with the meteorological factors, plays all the game.

Priyanka: 6:03

That is happening for like, if not more than, 8 to 10 years, and it came into being in 2016 because it is not that pollution was not there. It was not readily visible. We don't agree to things which we don't see. Even as researchers, we don't agree to that. So it was in November 2016 that, in Delhi, we realized that when we opened our windows, there was a huge dense haze, and that is when we realized that this is not fog, this is smoke. So the levels had risen much more, but now the concentrations were visible to us by an akedai. So that is when we started talking about it. The newspapers were covering.

Priyanka: 6:52

Government agencies have always been working on this, but then the pressure was more to find out the solutions to it. Why is it happening? So it is, I think I will say, last 8 to 10 years that this subject of air pollution has gained momentum and the problem persisted before that also. It's just that now the public is involved. The policy makers were already involved. Now the researchers are working. The academy we have a lot of dissertation projects which are happening on air pollution.

Priyanka: 7:29

Earlier I remember when I started my PhD, and that is 2002. So I used to carry these monitors with me. These are research grades instruments for monitoring air. I remember taking it to some houses the lower income houses and they felt that I am here to check the water quality in their houses. So it was very new to them then that why do you need to test air? So I am from there to now we are in an era of low cost sensors, air pollution, trying to find out what is the intervention that will help us mitigate this problem, outdoors as well as indoors. Now the purifier also. Suddenly, the market of purifiers, air purifiers has also grown since 2016. Because that is when you see, that is when you realise that, yes, if I am having more problems or symptoms of cold and cough, probably I am allergic to certain pollutants which I am present in the air. So now there is a lot of buzz around the terminology of air quality and, specifically in last four to five years, we are talking about indoor air quality as well.

Simon: 8:54

Yeah, really interesting and there is loads to unpack there. But one of the questions I had for you was really trying to paint a picture of where India was as a continent with air quality and ventilation right now. And from what you are saying, it is probably a mistake we make when we talk about a lot of big land masses, that our focus tends to draw towards cities or particular events. But from what you are saying, there is a real mix in India of both geography and topography coming into play, seasons having a really big impact, the difference between herbal and rural divides that generate areas of industrial pollution and rural pollution. So it is a real mix and seasonal yeah, seasonal. Just like North America have learnt over the last few years that air pollution does not know boundaries either, so pollution from one area can find itself in another area.

Simon: 9:57

You were talking about stubble burning. North America has been dealing with wildfires, particularly over the last couple of years, so it is a really complex jigsaw puzzle. I guess that you are trying to unpack. It is not just specific events or specific areas. There is a whole lot to play, a lot to play when it comes to air quality.

Priyanka: 10:19

We are on the second block of a thousand block puzzle, so we are trying to just move into how to put everything together, but it is too early, too nascent. Specifically, if I talk about ventilation in India, the perspectives are such that the houses were earlier designed in a manner where the residences all had courtyards. It was a norm to have a courtyard in houses earlier, so that process helped in good ventilation in the houses, the government offices or the offices. Earlier and I am talking 20, 30 years back, they also were. They used to have open verandas, open spaces and so ventilation.

Priyanka: 11:10

Well, india, if I even say now, we are a naturally ventilated, dependent country. So we prefer being in an environment which is naturally ventilated and also the accessibility and affordability in terms of the resources, for not everybody would have air conditioners, not everyone would prefer air coolers. It is very hot at times and I remember during my childhood, also during the peak of the summers, we used to just go to our terrace and have a good night's sleep there. So it was a pleasant environment. It was not that it was. The heat has been so much that we cannot sleep, but now it is.

Priyanka: 11:55

Suddenly we have moved from outdoors to indoors and that has complicated the problem more.

Priyanka: 12:03

Our movement from outdoors to indoors means that our comforts are not totally dependent on the meteorology, on the nature, and it is also related to the developments which are happening around us.

Priyanka: 12:18

So, not now, but 15, 20 years back, regular felling of trees, cutting of trees in the name of urbanization, was normal. We did not realize what problems we are causing for the future generations to be with. Now this cutting of trees and lot of concrete, lot of roads as a result of development and if I talk about Delhi and nearby areas, that is what I have seen in last 20 years. There has been tremendous development new highways, new roads, new places, residences, high rise buildings, they all have come up. But eventually that has contributed to the urban heat island effect which is very common in cities. Now, as we go outside Delhi, or NCR as we call as National Capital Region, the things are much cooler. The temperature is like at least 2 degrees less than what it is in Delhi. So the perceptive feeling of 20 degrees and the perceptive feeling of 24 degrees, 23 degrees, is different. People feel more hot in urban built environment, I would say.

Simon: 13:42

Isn't that the global story though? This move indoors, this indoor generation that we have created, and traditional buildings have been built for centuries to deal with the environment that they sat in, whatever region that was, and, like you say, it is the same in the Mediterranean and the tropics courtyards, outdoor spaces, lots of solar shading environments that were designed to manage thermal comfort, and you build up resilience to hot times and cooler times, and people were very good at that, but the buildings were generally outdoor spaces. So what you are saying is it is like a double effect. In India, you have got this urbanization and an increase in pollution and at the same time, we are moving people into boxes and shutting them and closing them down In the boxes, which are probably a condition, and they throw out the warm air.

Priyanka: 14:43

We are already in an urban heat island kind of effect and that is increasing the problem. So the natural tendency to stay in normal or resilience to bear that much of heat has also gone down amongst the younger generation and the people of my generation also. So the moment we are in a heat we want to get into a car. The car needs to be air conditioned. The moment we get out of the car we need to get into the office, which is air conditioned On the office. When we come back we need to be in the home and switch on the AC.

Priyanka: 15:21

So I am not saying it is wrong in a way, but the uncomfort levels have also, I would say, deteriorated because we used to have more resilience when we were younger, when we were children, we used to sleep outdoors and we used to sleep, sit below the trees and play around the trees. And now you don't see, that is affecting the next generation in that sense they are not able to bear a lot of heat, lot of cold, lot of any extremes of temperature. So the exposure again that makes a lot of difference Now, since they are not able to bear that much of heat or cold, they stay indoors. That is when we are indoors the problem starts, because we feel somehow everyone I have talked about it a lot the general tendency is that we are outside, oh, it is very polluted, let's go inside, we will be better off. So I don't understand that. How can being inside be better off if you are moving into an office which is fully carpeted? If you are into an office which has probably air conditioned, but with the filters or pre filters which have not been cleaned regularly and these are certain where the differential pressure has not been maintained or there is no mixing, there is not a good air exchange rate that has been maintained.

Simon: 16:56

I was going to say that, actually, priyanka, both in the non-residential, the office space and the home environment, the perception of a lot of people is an air conditioned space is a fresh air space, because it feels that the association of cool with fresh is quite strong, I think, for humans. So we feel that when we move into an air conditioned space that somehow the air quality is better than that muggy, warm feeling we have outside, when it can be the complete opposite, in fact, can't it?

Priyanka: 17:31

It is more or less. It is complete opposite. Believe me on that, because when we move inside, we tend to confuse ourselves between comfort parameter in terms of temperature, and the freshness of air. Fresh air, even if, in present scenario, the moment the sun comes out, the air outside is much fresher because the pollutant levels dissipate in the presence of sunlight and the winds. Once the winds pick up, we are in a better state, but the tendency of not opening the doors and windows, suddenly pooping yourself in the realms of the room or the.

Priyanka: 18:15

You see, india, we don't have a lot of heating systems. We are mostly dependent on the cooling conditioned air. Now, the conditioned air during winters. What happens is we have these oil heaters. People use oil heaters and that keeps them warm. Not everyone is able to use that. They use radiators, they use the people who cannot afford it. They burn wood and sit around it. So eventually we don't realize that probably we are not solving the problem, we are adding to it. So, winters, the best way to keep yourself warm is close all the doors and windows and sit in a room without realizing that CO2 could be an issue If you have a lot of occupancy, like I remember in my classes when I go, suddenly during winters because they close all the doors and windows and during winters there are 50 students in that particular room feels like that.

Priyanka: 19:17

You are not able to breathe. And that same room during summers, the doors and windows are open, it's very comfortable. So the practices, the behavioral patterns also have an impact in terms of seasons, like in Mumbai. Mumbai, they have seen. So I am assuming I assumed that you know things would be better. But this year Mumbai has also joined the list of the most polluted cities. So even when we have one intervention or mitigating option, solution in terms of sea waves or sea breeze, which tends to take away the pollutant load from the city towards the sea, then also the levels are so high. So we tend to. You know, we really need to look into how we can actually make sure, first and foremost before moving into the indoor part to it. The outdoor has to be better, it has to be better.

Simon: 20:22

So is your sense that in general? You just said Mumbai has just recently joined the list of polluted cities. Is your sense that air quality is still deteriorating? Outdoor air quality is still deteriorating in India or, with this increased awareness, are you starting to see that leveling off or improving in some cities? What's your general sense of the trend overall?

Priyanka: 20:49

I think things are improving in terms of we are looking at the innovative solutions for improvement. We are trying to mitigate options, but that is happening at a local level. That is not. You know, if I am in the suburb of Delhi and things are taking care of well here, that does not mean that Delhi will be better off or worse, because air anyways, it's very, it's a very dynamic composition that we are looking at what wind is blowing where it is blowing, what temperatures we are looking at. So the solution has to be holistic. I feel the solution has to be implemented in all the possible areas which are considered hot spots together and for a longer duration of time. That is what we have to look at.

Priyanka: 21:47

And there are policies. They are very good policies and the National Clean Air Program has kicked in and they have talked of very good policies. There are certain rated response action plan. We call it as GRAP in India. So when the levels of pollutant cross a certain level like air quality index goes above 200, 300, there are certain norms which are followed. You know we need to shut down the power plants, probably. The vehicular traffic has to be reduced, the schools, if we understand the levels are very high to be affecting the health of the individuals. The schools are closed, so that's another holiday for the kids here, the pollution days so. But they are good changes which are happening, but since this is a problem of longer dimension, it will take some time to actually show results.

Priyanka: 22:49

But, having said that, there is always a need for building capacity and creating awareness on those terms because, like I'm telling you, this is winters. We do have certain bonfires. It's very common in India to have bonfires. So I think we need to be aware as citizens, as a community, that if the air quality index is very high is, let's say, 300 or more than that 350, then we need to avoid for some time adding to the problem, not going for certain practices which could add to, even by a bit. You know, a drop or two in a full glass, we make it spill, so that's how it is.

Priyanka: 23:37

So I think the government is doing good. They have devised very good policies. We are working on them. It needs a more citizen centric approach, I feel, and that will only come when we are looking at more people coming together, and they are coming together Now. I at the amount of groups and activism that I see in the field of air pollution. This is very good because from the time if I say that, talking about you know, have you come to check the water quality? To people understanding what the air quality sensor is and what it looks like, we've come a long way and that's hats off to the work that we are doing. Slowly and gradually, we are moving there and I think with the kind of emphasis or impetus this aspect is getting in India, I think in some time we'll have very good solutions.

Simon: 24:37

And it's just as a frame of reference. It's not just about the needed direction of travel, it's about the distance that needs to be travelled and for people that have some sense of air quality parameters for perspective, you're talking about very high levels of poor air quality indexes there, With risk is that that becomes normalised in some way. So when you're talking about air quality indexes in the 300s, you're talking about particulate matter pollution, 2.5. What kind of levels outside are you seeing at those kind of levels? That is in the hundreds, isn't it?

Priyanka: 25:25

Yeah, it is around 200 or something, but these levels are not across the year. You don't notice these level across the year. It is during the winters that all the wrong elements come into play together, and that is when these levels because in summers we are good, we are much better in summers in terms of the pollution levels it is only when the winter sets in, specifically in the northern region. That is when we start moving towards. Every small inch of action has an impact, which is paramount.

Simon: 26:06

And I was going to say that some things are in your control and some things are outside of your control. You can't control weather, you can't control high pressures or where a city is located at an elevation perspective. These things are outside of our control. But things like traditions and behaviour, like you said, stubble burning on fields, bonfires being lit, behaviours indoors, cooking practices, those kind of things they can all have a massive difference at the right time of year. But that is a shifting culture and tradition and behaviour. That must be an incredibly difficult thing to start to think about and tackle, I guess.

Priyanka: 26:51

I think, yeah, if you would have talked about this 10 years back, I would have said I don't know how it will turn out. But the way India is progressing, we are coming up with very good solutions. We are taking this stubble. We are making pellets, these stubble pellets which can be used in power plants or for energy generation. We are using it as mulch. We have device technologies wherein these cedars come into play and the farmers don't have to burn the stubble. So there are solutions which are coming up and in last 10 years, I am very proud to say things have moved very rapidly.

Priyanka: 27:29

In India, we are actually very, very concentrated on what the solution is. Problem is always there, but are we concerned about solutions? Yes, we are concerned about solutions. Now, what we are moving towards is making these solutions sustainable. We really need to make them sustainable because solutions are there and we have amazing set of entrepreneurs who are coming up. They are designing good products which help these table, turn them into these mulch or manure. They are developing them into pellets. So we are going into that phase of very good phase of circular economy where we are using all the waste that is coming and utilizing.

Priyanka: 28:19

The problem of stubble burning started because it is a waste For the farmer. It is a waste. So how do that waste get treated? If it is treated at source, the problem will be resolved. So hence, I think the way the technology, the entrepreneurial spirits in India and the innovation is moving and the younger generation is driving this forward, I am hopeful that I think in some time we will be much better. We are in much better place than six years back. We will be much better place again. We should be able to overcome that.

Simon: 29:01

One of the universal truths of air quality and health outcomes appears to be that it always affects the most vulnerable in society the most. We see the poorest and the most exposed suffer the most, and I am guessing that is the same in Delhi and India in general. There are specific circumstances for the vulnerable that make them more exposed than others. Would that be fair to say?

Priyanka: 29:32

If I put it into perspective with my doctoral research. When I did it started in 2002, I did my monitoring in 2004,. That is the time when biomass fuel was cheap and readily available and people thought that let's save on the cleaner fuel and then go for biomass fuel. Now that paradigm shift which has happened in these many 20 years two decades is that the government has come up with very good policies in terms of Pradhan Menthi Yorjna for cleaner fuels. So they provide these cleaner fuels in terms of liquidified petroleum gas to the poor at a very subsidized rate. Now this has changed the behavior or the pattern. People know that probably earlier LPG used to cost more and that was a deterrent for the poor people to use it and they would only go for wood smoke or cow dung chulhas that is what they used to be working on. But now these energy efficient cookstuffs have come into foray. The government is disseminating or distributing these cookstuffs in areas where you don't get this supply of liquefied petroleum gas In our urban built environment, in places where people can afford it. We have shifted to the PNG, so things have moved to the cleaner part of the fuel and the government has taken steps in terms of vehicular pollution also. We have moved from Bharat stage 6. So the cleaner fuel has come into play. The government has come up with a policy wherein a petrol car has to be discarded in 15 years. It cannot run in Delhi and NCR. So these are smaller but very important steps which are coming into play, which in the long run will surely show the results.

Priyanka: 31:52

And especially the schemes of using cleaner fuels as a subsidized rate has made a lot of impact amongst the poor, because I remember one very important incident when I was doing my PhD. So this lady had access to the gas staff and the clean staff LPG. But she thought that anyway we have this tree around us, let's break the branches, put some fire and we can put it on here. We called it as Chula. Now for her, one day of saving means at least saving 15-20 rupees, which is good enough for her if she is getting something for free. Now, since the cleaner fuels are subsidized, they don't think that way. So the behavior patterns have also shifted. They are looking at what are the positives of looking at cleaner fuels, and in terms of their health also.

Priyanka: 32:51

It's not just about the economy. It was also in terms of the women cooking on chulas. They were exposed to PM 2.5 levels of around 2000 microgram and that I have recorded in my study. And it was astonishing because she was unaware that she is being exposed to those levels and she is cooking with those biomass fuels and very merrily sitting there in that environment for a long time Now, shifting there to this. The moment they shifted from that to the liquefied petroleum gas, as we call it as LPG, the levels have gone down. It is not as high as it used to be. The problem of particulate PM 2.5 has more or less been resolved, so our dependency on these chulas has gone down. Thereby the poor can still now afford a cleaner fuel. That has been a transitional change.

Simon: 33:56

So one of the main challenges was the direct exposure to combustion products from cooking and heating in spaces. A lot of the other challenges we see in public and social housing throughout the rest of the world is down to the quality of housing and the density of occupation of those types of properties, because it is not just combustion pollutants we are concerned about. It is bio-effluents and VOCs and other chemicals and formaldehydes and radon, and you name it. The more tightly you pack people into a small box, the more exposed they generally are. Is there some equally low hanging fruit to the combustion devices in India, with general housing conditions? Do you think Is there some areas that are in focus for you when it comes to improving people's lives?

Priyanka: 34:56

I think, in terms of improving the health. Now, when we are talking about specifically indoor air pollution, the people who are using combustion products, they are being exposed to these very high levels of PM2.5, other volatile organic compounds, formaldehyde. But the point is that during my doctoral study, I tried to understand what impact does the socioeconomic strata has on the exposure of the people who are residing in these residences? So and I was amused to find the results because, as I am telling you, this lady was exposed to these high levels of PM2.5. I was assuming that in the middle and higher income group household in the urban built environment the levels would not be so high, and I was right. They were not so high. But the problem was, instead they were constantly high, not as high.

Priyanka: 35:57

This is like I am talking about 2000 microgram peaks, but for a smaller duration. Here they were consistently, let's say, 600 microgram across the day. Now, that was something astonishing, the reason being that in the better affluent households they are more women, or they are held, which are who are moving around, working in the places and, having said that, they have accessibility to different comfort aspects like air conditioners, and that feeling that they tend to close the rooms more. With the number of people which is high and the room being closed, the dependency on the help, on using the chimney and all. I think we are still at a very nascent stage to understand, in terms of health, what is more harmful that peak which went for an hour or two, or that constant higher level of 600 microgram per meter cube for 8 to 10 hours?

Simon: 37:09

That is a really interesting point and that difference between acute exposure and chronic exposure. What is more damaging long term, harmful long term frequent exposure to short term spikes or long term chronic exposure permanently? Perhaps an interesting window for the future, as more people quality of life is improved and perhaps they move towards more mechanical systems and air conditioning, that you may be removing acute spikes of exposure to certain pollutants and introducing chronic, long term exposure by the way people live. Yeah, that's really fascinating.

Priyanka: 38:00

So that's exactly now. We had a very good study that we did it, ironically just before COVID happened. We had this study from October 2019 to February 2020 and wherein we tried to assess various micro environments, including schools, colleges, hospitals, offices, two under cinema halls, restaurants, to understand how the dynamics come into play. Now, what we noticed was that the levels of different pollutants in different micro environments rise at different levels. So I cannot say that I'm teaching in college, so probably that's a naturally ventilated place, so it will be better off. It gets closed at night. If you have new furniture, you're using chalk dust and yes, that was important.

Priyanka: 39:02

Chalk dust is an important aspect, especially in schools, wherein we have these green boards and we write on. The teachers do write on the blackboard. The kids are sitting very close to the blackboard area, so we have this little exposure and once the teacher leaves, there is a whole line of this chalk dust below. So every time the kids go out, kids come in and there is any kind of activity, there is a regular resuspension of this chalk dust. Now, this chalk is calcium carbonate. So if a child during winters and these are very, very intriguing research questions and ideas which I still have During winters, when mostly the doors and windows are closed, especially in the northern region of India, and this kids are going out, they are coming in and then again closing the doors and windows. It would be interesting to see their exposure in those four months in terms of disability, adjusted life years. Is the abscintism increasing? Are the students falling more ill? Is it that they feel suffocated or they feel like they need to? You know they are more in the having those sick building syndrome symptoms over a period of time. So these are some research questions that come to my mind when I talk about it.

Priyanka: 40:36

But, having said that, the three vulnerable locations in Delhi, specifically, we monitored around 37 locations. This study was done in association with Sirka at IIT Delhi and we found out that the three micro environments which were of most prime importance for us were schools, colleges and the hospitals, don of which, in terms of human exposure, have a vulnerable population in them. So and all the priority pollutants if I talk about, they were PM10, pm2.5 and TVOC, total Volatile Organic Compound. So now the idea is to understand, because that was the period of winters during in Delhi. This study was done in Delhi, so this is a winter period I am talking about. It would be really interesting to see in the same place, if we monitor during summers, what will be the dynamics of these three priority pollutants that I am talking about PM10, pm2.5 and Total Volatile Organic Compound.

Priyanka: 41:54

Also, I have realized CO2 plays. We don't put it under pollutant, it's a surrogate index for ventilation. So levels of CO2 needs to be monitored. We somehow tend to neglect it. But having said that, we are a good population country, so especially in the public's places, we should have if we can look at airports do have a sensor based monitoring display when in we get to know what is the level of CO2 in that particular airport. But taking a lead from there, if we can have it in all the public's places, it will generate awareness. It will also bring CO2 as a highlight, especially in high occupancy areas.

Simon: 42:45

And also, as we have seen in the non-residential spaces. One of the values of monitoring CO2 is it can break that assumption that an air conditioned space is a well-ventilated space, because you can go into a well-air conditioned meeting room and see very high levels of CO2 and it's an instant red flag for people to say, ah, you know, the air quality isn't necessarily so good. Do you think there's a chance that you know? We're seeing it in many countries in Europe, for example, that governments are starting to mandate the displaying of at least CO2 monitoring in a lot of public spaces. Do you think that's something that could gain some traction?

Priyanka: 43:30

Yes, I totally think, and I think government is working towards this, also because they have put forward an indoor air quality guidelines for India in the national clean air program. So they have started working on it. They have. We have submitted a report on what could be the priority pollutants and what could be the interim guidelines for indoor air quality in India with the central pollution control board in 2022. The national green tribunal is also very active in India and they had, in April 2022, passed an order that all the public spaces in India should be monitored for indoor air quality. So I think that's a very good welcome step for all the work that we were doing, because there are some places and some places like schools, colleges, schools specifically, and hospitals that I feel they should have it, because both occupy the most vulnerable population. We have kids of like three, four years going in schools and they are being, you know, exposed to certain levels the parents. It's a right to breathe good air, so that the parents should get to know what air is my child breathing.

Simon: 44:55

And you did some study work around exposure to things like traffic pollution in and around schools, didn't you? And developing guidance for children. Can you tell me about that? What was that piece of work about?

Priyanka: 45:09

Yeah, that was the work that we did in collaboration with the PJMI Chandigarh and University of Saray, wherein we tried to understand the exposure levels of kids who are studying in schools which are near to the main roads or high traffic areas. If and it is generally like that, whenever there is a school, the people come, the parents come to drop them, they are, they have their car engines on, it stays there for a while, they're increasing the levels of pollution in and around that vulnerable area. So the idea was to find what could be the mitigation strategies to avoid that. So we came up with very good options of, you know, putting these trees, certain species of trees and bushes and this was a norm in India and sadly we are going back to what we were so these bushes are there which block the way or the route of these traveling, of these pollutants from the high traffic zone to the school.

Priyanka: 46:23

Now, schools in India have a good big generally.

Priyanka: 46:26

They have a good big ground around them, right.

Priyanka: 46:31

So the idea was to identify which are the areas where the pollution comes from.

Priyanka: 46:36

Probably the places where the parents park their cars or they are, the engines are running and they are just dropping off the kids and try to put the right species of trees, bushes, plants to create a virtual wall, a green wall which can avoid the level of particulate which travels from that area to the school and reduce the exposure of the kids from that particulate concentration. Also, we did one of my colleagues also did a study, similar study in Delhi that was way back wherein she tried to monitor the levels of particulate in a school. That school was also very near to the main road, so the classes which were closer to the main road reported higher levels of particulate than the classes which were away from the main road. So if we can create any kind of blockade of we can put a gamut of trees or bushes which can block the inflow in flux of these pollutants from the main road to the schools, to the classrooms, I think we should be, even by a small percentage, it should be good.

Simon: 47:58

Yeah, yeah, and greening in general doesn't do any harm. As you said, there's been a propensity to remove trees and plants from our urban areas so that it helps with shading and cooling and everything else that goes with it. Were you able to evidence some benefits of doing that? Were you able to show outcomes from that kind of work?

Priyanka: 48:22

No, I think it has happened very recently. It will take some time to actually see the outcomes and the outcomes will come in a very indirect form. We really need to identify how do we see the outcomes? If we are monitoring, like one of the schools, they are monitoring air quality, indoor air quality in their schools. So the outcome that we are looking at is one way is looking at the absintheism, the rate of falling ill in the kids and any kid who is coming if he has some illness like wheezing or cough fold, how fast he gets better if he is in that environment. So there are small steps which are happening in certain schools. They have been proactive schools in Delhi who are working on it. But yes, again, they are quite, you can count them on numbers. So we are looking forward to it.

Simon: 49:25

What was the impact of Covid in India generally on air quality awareness and the importance of indoor environments to mitigating risk? Did it raise some awareness in the short term there, like it did in other areas? How has it generally taken and has it been overall a benefit to air quality awareness in general?