Indoor air quality is in the News. What has been a longstanding health issue has hit the spotlight. Due to a number of issues and events occurring over recent times, the air we breathe in our homes and workspaces is becoming visible.
Indoor air pollution is one of the top five environmental risks to public health, according to the US Environment Protection Agency. Annually, 3.8 million people worldwide prematurely die from illnesses attributable to household air pollution. It is not one single thing that has created this problem with our indoor air, but a series of trends, decisions and changes that have brought us to the point where identifying and dealing with IAQ problems has now become an absolute necessity.
Major changes in lifestyles and work habits have occurred in recent times. Construction techniques, ventilation equipment, cleaning products and procedures have all changed dramatically. A change in attitude to health and well-being and the ability to access information have ensured that IAQ is now at the forefront of our consciousness.
Why Is Indoor Air Quality So Relevant Now?
1. Global population is staying at home
According to the EPA, we now spend 90% of our lives indoors. In reality, since March 2020, ‘stay-at-home’ orders and remote working/learning due to the pandemic probably mean that this figure is higher. But the move to indoors has been happening gradually over the last century.
The changing nature of work has had a dramatic impact on potential IAQ problems. The move from an agricultural and manufacturing society to a society where information-based technologies and services are dominant means that much more time is spent indoors. Basically, we have moved from the farm to the office or home office.
And in this indoor environment we are exposed to pollutants that are in the outdoor air (every time we open a door or window) but also to many more pollutants specific to the indoor environment. These include allergens like dust, pet dander and mold, particles released by wood-burning fires, cooking and candles, and chemicals released by flooring, furniture, paints and appliances.
2. Era of Pandemics
Ecological destruction and unsustainable consumption have entered humanity into an “era of pandemics,” according to a report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, a global expert body advising governments.
There is no doubt that Covid-19 has catapulted our awareness of indoor air quality to the top of our priorities but according to experts, Covid-19 isn’t even ‘the big one’ . We have to prepare ourselves for an even more devastating pandemic in the future.
“Without preventative strategies, pandemics will emerge more often, spread more rapidly, kill more people, and affect the global economy with more devastating impact than ever before,” says the same report.
The panel said that Covid-19 was the sixth pandemic since the influenza outbreak of 1918 – all of which had been “entirely driven by human activities”. Deforestation, agricultural expansion, urbanization and other land-use changes are responsible for about a third of all new diseases since 1960. These activities put humans in increasingly close contact with wild and farmed animals and the diseases they carry. Seventy percent of emerging diseases, such as Ebola, Zika and HIV/AIDS, are zoonotic in origin, meaning they circulate in animals before jumping to humans. Around five new diseases break out among humans every single year, any one of which has the potential to become a pandemic.
Covid-19, caused by the SARS-CoV-2 virus, is a respiratory virus and is transmitted in several ways: Contact transmission is infection spread through direct contact with an infectious person or with a surface/article that is contaminated. Droplet transmission is infection spread through exposure to virus-containing respiratory droplets (i.e., larger and smaller droplets and particles) exhaled/coughed/sneezed by an infectious person. Because droplets are too big to remain suspended in the air, transmission is most likely to occur when someone is close to the infectious person, generally within about 6 feet – hence our need to socially distance.
Airborne transmission is infection spread through exposure to those virus-containing respiratory droplets comprised of smaller droplets (aerosols). Aerosols are tiny in comparison to droplets and so can remain suspended in the air over long distances (usually greater than 6 feet) and for longer time (typically hours).
It is primarily this airborne transmission that has forced us to transform the way we think about our indoor air. Diseases that are spread efficiently through airborne transmission (TB, measles, chicken pox for example) tend to be very contagious as they can quickly reach and infect many people in a short period of time. It appears that SARS-CoV-2 is mainly spread by contact and droplet transmission but more and more evidence is coming to light to suggest that airborne transmission is a more important form of spread than what was previously thought.
Airborne transmission of SARS-CoV-2 appears to be more likely in certain circumstances – for example, in enclosed spaces within which an infectious person either exposed people at the same time or to which people were exposed shortly after the infectious person had left the area. Or where there has been prolonged exposure to respiratory particles, often generated with expiratory exertion (e.g., shouting, singing, exercising) that increased the concentration of aerosols in the air space. Inadequate ventilation or air handling that allows a build-up of virus-laden aerosols also creates an environment ripe for the rapid spread of the virus.
What is not known is what proportion of SARS-CoV-2 infections are acquired through airborne transmission. Research is ongoing to help us understand how viral-laden aerosols and droplets behave in the air, how transmission occurs, how air cleaning/masks/other mitigation measures can reduce viral load in the air.
Although we are primarily concerned with SARS-CoV-2 in indoor air, aerosolized SARS-CoV-2 does not exist in isolation. Recognition of all airborne microorganisms and how they may interact with many of the chemicals in our indoor air needs also to be studied. It is clear that a greater understanding of airborne viruses and microorganisms in indoor air is needed to develop strategies to protect human health in this era of pandemics.
3. Homes have become more airtight
Efforts to make homes airtight to improve energy efficiency have created buildings with reduced ventilation rates resulting in the build-up of indoor pollutants to harmful levels that would be unacceptable outdoors.
There is no doubt that an awareness of energy costs has impacted indoor air quality. Architects, engineers and building managers often overemphasize energy efficiency to the detriment of occupant comfort and performance because the high cost of electricity, gas or oil.
The workplace too has changed, with computers, printers, faxes and photocopiers all being potential sources of harmful VOCs. . The presence of computers (often multiple) and printers in the home- now that our homes are increasingly also becoming our offices- adds a further source of potentially harmful VOC emissions.
4. Increasing incidence of asthma
According to the Centres for Disease Control and Prevention (CDC), 1 in 13 people have asthma.
Asthma has been increasing since the early 1980s in all age, sex and racial groups and now more than 25 million Americans have asthma. This is 7.7 percent of adults and 8.4 percent of children. It is the leading chronic disease in children. In 2017, 1 in 12 children had asthma. Currently, there are about 6.2 million children under the age of 18 with asthma, according to AAFA. It is the top reason for missed school days; in 2013, about 13.8 million missed school days were reported due to asthma.
Each day, ten Americans die from asthma, and in 2017, 3,564 people died from asthma. Many of these deaths are avoidable with proper treatment and care.
These stark statistics have opened our eyes to the relationship between air quality and our health and well being.
5. Increasing incidence of allergies
Allergies are the 6th leading cause of chronic illness in the U.S. and more than 50 million Americans experience various types of allergies each year. Allergic rhinitis, often called hay fever, affects 6.1 million of the children population and 20 million of the adult population. In 2015, 8.8 million children had skin allergies.
The reasons behind increasing incidence of asthma and allergies are unclear. There are many theories and it may be that it is the interaction of all or some of these that is the cause. Climate change, the hygiene hypothesis, obesity, sedentary lifestyle, overuse of antibiotics, pollution and vitamin D deficiency are the most likely hypotheses.
6. Increasing interest in health and wellness
Interest in IAQ is part of the ever expanding health and wellness movement. The air we breathe is, after all , fundamental to our health. The realisation that we should visualise what is in our air so that, just like we would not drink dirty water, we shouldn’t breathe dirty air is becoming clear to this new generation. Our planet is under threat and this has made clear to us that our existence is fragile. The trend of wellness is here to stay, spearheaded by a generation that prioritises health and wellbeing more than any generation before.
7. Worsening Air Pollution
Outdoor air pollution penetrates indoors, and because Americans spend a majority of their times indoors (>90%), the majority of exposure to outdoor air pollution occurs indoors. And new data shows outdoor air pollution deteriorated in the US in 2017 and 2018 – a reversal after years of sustained improvement and this has significant implications for public health.
In 2018 alone, poor air quality was linked to nearly 10,000 additional deaths in the U.S. relative to the 2016 benchmark, the year in which small-particle pollution reached a two-decade low, according to researchers at Carnegie Mellon University. The study focuses on the air pollution caused by the smallest particles (PM 2.5) which is of particular concern to public health experts because its microscopic size means it can be inhaled deep into the lungs and absorbed into the bloodstream.
8. Forest fires
The climate change we are experiencing exacerbates the factors that create perfect fire conditions. Lower rainfall and warmer air temperatures dry forests and other vegetation. Add strong winds into the mix and this creates a dangerous recipe for wildfire. Not only is the average wildfire season three and a half months longer than it was a few decades back, but the number of annual large fires in the West has tripled — burning twice as many acres.
These fires are more often encroaching on densely populated areas and even destroy entire towns, spreading noxious smoke many hundreds of miles to surrounding areas and warnings for city populations to stay indoors and close windows. Resulting media coverage also leads to an uptick in awareness of air quality.
9. Pollen tsunamis
Pollen is a fine powder produced as part of the sexual reproductive cycle of many varieties of plants. There are three big peaks in pollen production throughout the year. Trees like oak, ash, birch and maple cause pollen surges in the spring. Pollen from timothy grass, bluegrass, and orchard grass peaks over the summer, and ragweed pollen spikes in the fall.
Some types of pollen, those with tiny diameters, can travel deep into the lungs and cause irritation, even for people who don’t have allergies. High concentrations of pollen in the air can spread for miles, even indoors if structures are not sealed.
Evidence is showing that pollen, an allergy trigger for one in five Americans, is surging year after year. And a major driver behind this increase is climate change. Rising temperatures caused by climate change lead to longer allergy seasons and worsen air quality. In general, pollen is emerging earlier in the year, especially pollen from ragweed, and the season is stretching out longer and longer. Between 1995 and 2011, warmer temperatures in the U.S. have caused the pollen season to be 11 to 27 days longer. Longer allergy seasons cause more allergies and asthma attacks.
Change in carbon dioxide concentrations from a preindustrial era level of 280 ppm to concentrations today of more than 400 ppm has led to a corresponding doubling in pollen production per plant of ragweed. More pollen production usually means more seeds, which means more ragweed in the next season.
In addition to the quantity of pollen, rising carbon dioxide concentrations increase the allergenic peptides on pollen. The peptides are the molecular signal that triggers our immune response, so more peptides on a given pollen grain increase the severity of the allergy.
So it’s not just more pollen, the pollen itself is becoming more potent in causing an immune response.
10. Information Accessibility
Searching for information which would have required a major effort just a few years ago now simply requires the few moments it takes to type it into a search engine.
The power of the Internet to quickly educate individuals has empowered people to take control of their environment. People now have information (although not always accurate) to support their decision to improve their conditions at home or force their employer to.
In general, people are not as willing to accept the contention that ill health is a normal part of life. This intolerance of poor air quality in workplaces, public buildings and restaurants fuels continued interest in identifying and resolving IAQ problems.
Advances in technology has enabled us to assess and measure indoor air quality in a way that was impossible in the past, giving us valuable information about the air we breathe that was previously unavailable. Fortunately, as information on indoor air quality becomes more widespread, we can move from reacting to problems and complaints to proactively preventing problems from developing in the first place.
Indoor air quality is clearly vital to health and always has been but until indoors became the place where we spend the majority of our time, this fact wasn’t a priority. Combined with the fundamental change of our living habits are factors such as increasing incidence of asthma and allergies, building practices and energy efficiency, worsening outdoor pollution, forest fires, exposure to new airborne diseases and pollen tsunamis. And it is the coming together of these issues that has raised our awareness of indoor air quality to a new level. Suddenly we want to see what is in the air we breath. And as technology has now made the invisible visible, giving us knowledge of what is in our air and the impact it has on our health, our indoor air quality is undeniably highly relevant.