Indoor air quality (IAQ) is a crucial aspect of human health and well-being. However, achieving adequate ventilation in homes and other indoor spaces can be challenging, particularly when outdoor air pollution levels are elevated due to smoke from wood-burning stoves. This article explores why poor ventilation in polluted environments poses a heightened risk of pathogen spread.
Factors Hindering Ventilation in Polluted Environments
Wood-burning stoves, used for heating and cooking, release particulate matter (PM), nitrogen oxides (NOx), and carbon monoxide (CO) into the atmosphere. These pollutants can accumulate in extended areas, especially under certain weather conditions. Normally, warm air rising from the ground carries pollution upwards, dispersing it into the atmosphere. However, during the winter, a warm layer of air can settle over a city like a lid, trapping cold air and pollutants near the ground. This phenomenon, known as a thermal inversion, occurs when a warm air mass above restricts the upward movement of cold, denser air, trapping it along with pollutants close to the surface. Thermal inversions are particularly prevalent in cities like Los Angeles, Mumbai, Granada, and Mexico City, where cold, dense air gets confined within mountain basins or valleys.
They say that good air quality is a fundamental right for all, and at the same time, they say that 99% of the population worldwide is exposed to air pollution above WHO Air Quality Guidelines. Mixed messages here. Even though I have already shared the story on a Tweet thread, I decided to write an article as well because of the permanence of the article and because it is easier to share.
December 17th, 2023
I arrived in Granada, Spain for the holidays. A blanket of smoke was covering Granada and the small towns around with a total area of over 100 km2. Although I was super tired, the intense smell of smoke inside the apartment and the fact that I knew that there was a lot of particulate pollution indoors didn’t permit me to sleep well.
The holidays are a time for celebration, filled with the warmth of family gatherings, delicious meals, and festive decorations. However, amidst the joy, some seemingly harmless traditions can have unintended consequences for our indoor air quality.
1. Culinary Combustion: The Peril of Holiday Feasts
Holiday dinners often involve hours spent in the kitchen, with ovens cranking and stoves blazing, filling the air with a medley of aromas. While tempting, this culinary combustion releases volatile organic compounds (VOCs) from cooking oils, burning meat, and even vegetables. VOCs can irritate eyes and lungs, exacerbate respiratory issues, and contribute to poor air quality. Keep ventilation on!
2. Fragrant Fumes: The Unseen Threat of Candles and Incense
Candles and incense are staples of holiday decor, adding warmth and ambience to our homes. Unfortunately, their burning releases pollutants like particulate matter and volatile organic compounds, impacting air quality. For those with asthma or allergies, these irritants can trigger unpleasant reactions. Say no to candles and incense burning!
The BS 40102, a fresh standard introduced in 2022 (draft released) by the British Standards Institute, focuses on assessing the health, wellbeing, and indoor environmental quality (IEQ) of buildings. It incorporates an updated best-practice method for addressing thermal comfort, indoor air quality, and overheating in buildings.
Regarding the new exposure limits, they are derived from various sources, including the DEFRA Daily Air Quality Index, WHO Air Quality Guidelines 2021, BREEAM and WELL Guidelines, and British Standard BS EN 16798-1.
Part 1 – Health and Wellbeing in Buildings
BS 40102-1 gives recommendations for the measuring, monitoring and reporting of the well-being and IEQ performance of an occupied building and the associated building services.
BS 40102-1provides an evaluation and rating system (IEQ performance score), the aim of which is to enhance IEQ, to create healthier buildings and improve the well-being of building occupants; including but not limited to staff, visitors, tenants and customers.
Understanding ASHRAE Standard 241: Control of Infectious Aerosols
ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers, is a global professional organization committed to advancing the arts and sciences of heating, ventilation, air conditioning, refrigeration and their allied fields. They have recently introduced a new standard, ASHRAE 241-2023, which focuses on the ‘Control of Infectious Aerosols.’ This new standard is a significant step forward in addressing the transmission of airborne diseases in non-healthcare settings.
The Genesis of ASHRAE 241
The genesis of ASHRAE 241 was during the COVID-19 pandemic, where there was a widespread realization that ventilation rates in non-healthcare settings were not designed to mitigate airborne disease transmission. The pandemic highlighted the inadequacies of our buildings’ ventilation systems, and organizations scrambled to upgrade their systems without a clear understanding of ‘how much’ ventilation was needed.
Welcome to “Room by Room: The Home Organization Science Insights Podcast”! Air quality expert Sotirios Papathanasiou joined host Gabriella Joustra to discuss the crucial topic of poor indoor ventilation and its impact on one’s health and performance.
Sotirios, an esteemed advocate for clean air initiatives, shared his expertise in indoor air quality. In this episode, they explored the detrimental effects of inadequate indoor ventilation, including common pollutants and associated health risks. They provided practical guidance on improving indoor ventilation and empowered listeners to create healthier, more productive environments.
Join them as they delve into the impact of poor indoor ventilation on health and performance, offering valuable insights and actionable advice for a better living and working space.
It was brought to my attention by Dr. Howook Chang that most media are talking about wildfires, what the color of the sunset looks like, and that people shouldn’t go outside. However, no one is talking about the fact that smoke can infiltrate houses quite easily. Wildfire smoke can join you during dinner or while you are sleeping.
Air quality matters more indoors where we spend most of our time. So here is a series of things to keep in mind in order to breathe healthy air.
Monitor Air Quality
First of all, measure the air quality indoors and outdoors. The reason we need to measure both environments is that we need to benchmark the conditions and take decisions based on the data we have collected. Pollutants can easily come inside the house during ambient pollution events, whether is a wildfire, traffic, or a dust storm (e.g. Sahara Dust). Windows, doors, HVAC systems, or simply not good insulation are some of the main entrances of pollution indoors.
Let’s forget at the moment that combustion vehicles emit carbon dioxide (CO2), and focus on the occupants that spend time inside a confined space where they emit CO2 due to metabolite of cell respiration. Vehicles form part of the indoor spaces where humans spend a lot of time due to traffic or because they have to travel long distances.
Regulatory bodies have been controlling many aspects of modern vehicles; tires, mirrors, seat belts, airbags, screens, etc. However, they have forgotten to look into the air quality inside the vehicles and how it affects the driver’s cognitive performance.
I had the chance to visit New Delhi and Agra in India due to an annual conference that we had to assist. I was well informed about the poor air quality in the area, so I was prepared to breathe some pollution. I have read many articles and heard many testimonials about the situation there but still, a visit in situ helps someone understand the issue on a whole new level.
Some weeks ago, I published an article on “Why is Air Pollution Invisible” and I think during my visit to India I experienced all of the points clearly.
Immediately, once you come out of the aircraft, you can smell the air pollution. It is everywhere, indoors and outdoors. Even waiting in the immigration line for clearance you can smell it. I didn’t have the instrument in hand at that point in order to measure the concentrations, but from my experience and because air pollution was visible due to high levels, I estimate concentrations of 100μg/m3 of PM2.5. I want to make clear that I was still indoors.
From there, I headed to the hotel in a taxi. As you may imagine, the air quality was not better, but quite the opposite as the fumes from the relentless amount of unregulated vehicles were spewing everything they had in their engines. Particles of all sizes and gas fumes. Interestingly, more than 90% of the vehicle in the streets were occupied by only one person, the driver. On top of the air pollution in the streets, you can add noise pollution as the use of car horns is a tradition in India.
I managed to arrive at the hotel after a small accident with the car (no damages) where I took the air quality monitor out of my luggage in order to measure the conditions in the room. Unfortunately, it wasn’t safe either. The mean PM2.5 concentration during my stay was around 50μg/m3.
The hotel had some small air purifiers in the hallway, but the coverage area was too big for them to handle properly. I looked at the filters and they were pure black, who knows for how long they were running without replacement.
On day two, my nose didn’t register the smell of smoke anymore. I was one of them! Unable to smell the pollution and consequently remind myself that I need to find clean air. This is what happens to locals that don’t have options, eventually, they forget.
For simplicity, here you can see my PM2.5 exposure for the last date of my trip before coming back home. However, the particle counts for the smaller particles like 0.3μm and 0.5μm, which get lost with mass concentration values, were even higher reaching counts of around 400,000,000 particles per m3 and 40,000,000 particles per m3, respectively. By the way, according to the locals, I visited New Delhi during a good AQ time.
Enough with the AQ data, we know it is really bad, my main question was where all this air pollution comes from. Most people will tell me that it is due to vehicle emissions and domestic burning. Still, it doesn’t make sense though because the weather was warm and there was no need to burn logs for heating. Additionally, the issue was persisting all day and night. So after a conversation with a local professor, he pointed out that the main source was waste management. Basically, they burn garbage and these eternal fires create the smog that persists in the city and makes people really sick.
I talked about the car horns, but you will also hear many people cough. It’s normal as their lungs are suffering from chronic exposure to toxic air pollutants.
There is some good news, though. Once the local people realize the source of pollution as I did, they can fix it. New Delhi is populated by 15,000,000 people and I understand that the amount of waste they generate is equivalent to that number, but the management of the waste can’t be “burn it, it will disappear” because it doesn’t. Finally, vehicles need some kind of control and annual revisions that will force the drivers to maintain the car in optimal conditions like EURO 6 compliance does in Europe.
This is the first Artificial Intelligent (AI) written article on Indoor Air Quality. I was interested to see if technology understands the issue. I have done zero corrections. What do you think?
Indoor air quality (IAQ) is an important but often overlooked aspect of a home’s environment. Poor IAQ can lead to a variety of health issues, such as asthma, allergies, headaches, and other respiratory and cardiovascular problems. Given the health risks associated with poor IAQ, it’s important to understand the sources of indoor air pollutants, the measures you can take to reduce them, and the steps you should take if you suspect your home has a IAQ issue.
Indoor air pollutants come from a variety of sources, including mold, dust mites, pet dander, pollen, chemicals, and building materials. These pollutants can enter your home through open windows, ventilation systems, and other pathways. Poor maintenance of these sources can lead to an increase in the amount of pollutants in the air. For example, failing to regularly clean carpets and filters can lead to an accumulation of dust and other contaminants.
One source of indoor air pollution that is often dismissed is wood burning. Wood burning can produce both direct and indirect air pollutants, such as smoke, soot, and other particulate matter. The smoke can contain a variety of hazardous compounds, such as carbon monoxide, nitrogen dioxide, and formaldehyde. In addition, the smoke from wood burning can also contain other pollutants, such as volatile organic compounds (VOCs). All of these pollutants can be hazardous to human health, particularly if the exposure is prolonged.
Fortunately, there are several steps you can take to reduce the levels of indoor air pollutants and improve the quality of your home’s air. Regularly cleaning carpets, upholstery, and other surfaces can help reduce the amount of dust and other allergens in the air. Additionally, regularly changing the air filters in your air conditioning and heating systems can help reduce the amount of dust and other particles in the air. Finally, using an air purifier can also help reduce the amount of indoor air pollutants.
If you suspect your home has a IAQ issue, it’s important to take steps to investigate and address the problem. The first step is to identify the source of the problem. This can involve hiring professionals to assess the air quality in your home, as well as conducting tests to identify the specific pollutants in the air. Once the source of the problem has been identified, you can then take steps to address it, such as improving ventilation, cleaning regularly, and using air purifiers.
In conclusion, poor IAQ can lead to a variety of health issues, including asthma, allergies, headaches, and other respiratory and cardiovascular problems. Therefore, it’s important to understand the sources of indoor air pollutants, the measures you can take to reduce them, and the steps you should take if you suspect your home has a IAQ issue. By taking steps to reduce indoor air pollutants and address the sources of IAQ issues, you can help ensure your home’s air quality is as healthy as possible.
See The Air 