‘Secure indoor ventilation standards, or we end up inhaling high carbon dioxide’

Here in India, we are talking about outdoor air quality – smog and PM 2.5, given the current context for cities like Mumbai and Delhi, why should we be worried about indoor air quality ?

Basically, instead of talking about indoor or outdoor separately, we should speak about one air since the air that we breathe outdoors is the same as the one we breathe that is indoor. Also, it is important to address the air as a single entity instead of labelling it as indoor or outdoor because then it can be easily framed as a public health issue. So in a way, we cannot separate the air that is indoor from the one that is outdoor. We cannot separate these two airs unless we go inside a submarine or we board a space shuttle, then we will be completely separated from two different types of air, otherwise it’s not possible not to be exposed to the outdoor air even if we are indoors. As a result, the quality of indoor air is as important as that of outdoor air.

So when do you speak of one air, how do you really differentiate between indoor and outdoor air ?

The best authority here will be the World Health Organisation (WHO), which published the first air quality guidelines in 1989 and the second guidelines were published in 2000. Later, the guidelines were revised in 2005, 2010 and 2021. So in the earlier guidelines , the pollutants that cause pollution usually have outdoor origin where they are produced and later, they enter indoors. Later, in 2010 guidelines, it was listed that there were 14 different pollutants that are specifically emitted indoors. The WHO calls it selected pollutants and those pollutants are not as relevant, if you speak about them in the context of an outdoor environment. So, if we speak about particulate matter (PM) for example, their main sources would be outdoor activities like combustion, however, these pollutants also enter indoors of a house and gradually the lines of differences get blurred. Therefore, I personally propose a completely different definition of air quality, for me the sole quality of air is the one that promotes and affects health. Any quality of air or pollutant that is detrimental to our health should be avoided independently, whether they are exposed indoor or outdoor.

Your research focuses on proper ventilation for achieving right AQI standards. What are the effects of ventilation in terms of health recovery as per your research findings ?

There are two different types of pollutants in the air – microbiological and gaseous. So if you talk about which is more harmful ,then I would say that we have read and learnt a lot about PM 2.5 being one of the few hazardous pollutants that can harm our health which is generated outside. Therefore, in this context, ventilation is very important, since it plays in dispersing the pollutants of outdoor air when it travels indoor and if the indoor air is clean the adversity of the pollutants gets reduced. As a result, ventilation also plays a role in exposure to air quality. So now when the air indoors is getting filtered because of ventilation there are direct and indirect health benefits that one may feel, first of all clean air reduces stress and improves stress levels. This increases the productivity of people. On the contrary, inhaling pollutants also have potent effects, but these are not adverse and couldn’t be felt immediately as they are much more long-term. For example, if you smoke cigarettes, you won’t develop lung cancer immediately. Similarly, once you start inhaling pollutants, you won’t develop any signs immediately, but after maybe 20 years down the line, you may end up developing Alzheimer’s or dementia or maybe some lung disease. So in a way, proper ventilation is also a proxy to improved air quality.

In the Indian context, when we are investing substantially on air quality purifiers, how should we consider this trade off between ventilation and air purifier ?

We need to secure minimum ventilation standards, which needs to be a minimum marking of outdoor air that is circulated indoors or else we may end up inhaling high level carbon dioxide and other forms of pollutant that may have generated indoor as well. Therefore, we need to retrofit solutions in our homes and workplaces with the help of high efficient fans and filters so that in a way that it maintains a minimum standard of cross ventilation of air. Also the retrofitted objects should be serviced routinely to ensure their service delivery remains at the top.

India has seen an uptick in air conditioner sales in the past few years, the government has also asked manufacturers to set a minimum temperature at 18 degrees. Does this have any role to play in terms of air quality management in India ?

Firstly, an AC is not an air cleaner, they remove moisture and bring down temperature. There are solutions that can be retrofitted in an existing AC and by this way, the AC can become an air cleaner and you will not need a separate air purifier in place. In case if you happen to have another air purifier within the periphery of the AC, then it may affect the overall air distribution. Therefore, the solution is to have a retrofit. Which means, on one hand you have an air condition and you can retrofit a purifier on it which may give you the required service.

An air purifier is also very expensive. How can an average lower income group or middle class afford it ?

We have equated this analogy with the theory of purchasing a vehicle. The purpose of buying a vehicle is to ensure there is mobility, some people purchase high-end vehicles, some people purchase a basic model of any car, while some purchase two wheelers like scooters or bicycles. While the service of providing mobility is common in all the categories, however the quality of service in terms of comfort level is different in terms of each vehicle. Similarly, there are different kinds of air purifiers in the market. Some of them are fancy and are highly expensive, while some products would be affordable but wouldn’t look as fancy. But the common function of these products is to ensure the air is cleaned.

In your research you have mentioned that carbon dioxide is a marker for indoor air pollution. So how is carbon dioxide different from PM 2.5 particles ?

So PM 2.5 are particulate matters, while carbon dioxide is a gas. As a result these two matters will have different effects in our body. Mostly carbon dioxide is used as a marker for ventilation for spaces that don’t have a mechanical ventilation system and is full of people, therefore you will need a separate marker for it, for which carbon dioxide is used as an alternate marker to identify ventilation levels. Also, the primary source of carbon dioxide is human metabolic air, unlike particulate matter which is emitted artificially.

 

View this post on Instagram

 

A post shared by The Indian Express (@indianexpress)

//www.instagram.com/embed.js
Post covid people have adapted the habit of wearing masks. Does wearing masks also have side effects ?

There is some research that shows that wearing a mask can be harmful for people, so this is a trade off. But these are for mostly unhealthy people who have some lung problems or respiratory diseases. Even on healthy people, we have seen masks have affecting physiological effects. But for healthy people these effects could be recovered very quickly, however, there are no long term effects on health that may have been caused because of wearing masks.

In Mumbai ,nearly 50 percent of the population reside in slums, in crammed situations and many of them are situated close to polluted zones. According to you, what can be some of the practical measures to protect them from air pollution ?

These are extreme conditions and the fact that air quality and pollution are affecting the lifespan of the living in such situations is a secondary concern. There are issues related to malnutrition, then they have lousy conditions to live, poor sleep cycles, sanitation issues. These conditions are much more detrimental to them than air pollution. The issue of air pollution will only contribute to these problems. So removing air pollution will not make any big change. The only big change is to upgrade their lifestyle and that is how it can bring any change to their livelihood and improve their lifespan. For example, in Europe, part of the population is socially challenged. So we need to improve their lifestyle as well alongside improving indoor environment access to medication and healthcare is also improved. Indoor environment does play an important role, but all the other factors are also important.

“Inhaling pollutants also have potent effects, but these are not adverse and couldn’t be felt immediately as they are much more long term. For example, if you smoke cigarettes, you won’t develop lung cancer immediately. Similarly, once you start inhaling pollutants, you won’t develop any signs immediately, but after maybe 20 years down the line, you may end up developing Alzheimer’s or dementia or maybe some lung disease.”