After the COVID-19 pandemic and social distancing in indoor spaces raised awareness of the risks of infection in closed spaces and super-spreader events, scientists concerned about human exposure to other indoor contaminants and strategies to reduce risks are hopeful that the time has come for more action.

BERN, Switzerland – A dearth of data and low public awareness of the presence of pollutants in the indoor air we breathe are the greatest impediments towards making spaces more healthy, experts said at the first World Health Organization/Europe Indoor Air Conference.

The conference on Wednesday 20 September, was the first-ever WHO event focusing on the wide range of indoor air pollutants that can affect the health of people in modern homes and buildings. It was co-hosted by WHO’s European Region, the Swiss government and the Geneva Health Forum. 

The conference went beyond long-discussed issues of indoor air pollution from coal and biomass heating and cooking systems, which are a major issue in many low and middle-income countries, including parts of WHO’s 53-country European Region.

Overlooked for too long

“Indoor air quality has been overlooked for far too long,” said Hans Kluge, WHO’s regional director, speaking at the conference via video link from Copenhagen.

WHO’s European Region was the first to issue a number of guidelines relating to indoor air pollutants other than cooking smoke. More recently, WHO issued global guidelines for ventilation to reduce virus transmission, including the COVID virus, SARS-CoV2.

Some 150,000 people die in the World Health Organization’s European region each year from exposure to smoky coal and biomass fuels used for cooking and heating, a “shocking” number in and of itself, Kluge said.

But that is only part of the picture, with the health impacts of other indoor air pollutants still unquantified, Kluge added.

“Often there are more pollutants inside than outside,” said David Vernez, professor and head of department at the Center for Primary Care and Public Health at the University of Lausanne in Switzerland, at the conference opening. “We are probably only seeing the tip of the iceberg.”

With Europeans estimated to spend up to 90% of their time indoors, the quality of the air that they breathe within those spaces is vital to their health, Vernez said.

Also in the @WHO_European Region, we see an estimated 24,600 deaths a year from exposure to radon – a major cause of lung cancer – in household settings.

Another grim statistic underscoring the urgency of tackling #IndoorAirQuality.@Genevaforum https://t.co/xqr0ryBVjy

4/ pic.twitter.com/QJ2ul2A8QJ

— Hans Kluge (@hans_kluge) September 20, 2023

Sources of Indoor Air Pollution

Indoor air pollutants come from a variety of sources, including the buildings themselves, outdoor air and human activities. Radon, asbestos, formaldehyde, and other toxic products are commonly found in homes, offices, and public spaces and can pose a serious risk to human health.

Radon, a radioactive gas found in some soils and rocks, can seep into buildings and cause lung cancer. Asbestos fibers, which can become airborne during building renovations, can also cause lung cancer and other respiratory diseases. Formaldehyde, a chemical used in particleboard and other building materials, can irritate the eyes, nose, and throat, and may also increase the risk of cancer.

Indoor moisture from condensation and humidity in poorly insulated and ventilated bathrooms and kitchens can promote the growth of mould and pathogens that contribute to asthma and other respiratory diseases.

Inadequate air exchanges in crowded spaces or poorly ventilated rooms can also increase carbon dioxide (CO2) levels – with elevated levels potentially reducing cognitive performance, according to recent research. 

Breathing Clean: How Improving Indoor Air Quality Can Save Lives and Boost Productivity

Two million healthy life years lost

Pawel Wargocki, associate professor at the International Centre for Indoor Environment and Energy at the Technical University of Denmark, explained that an estimated 2 million healthy life years – a measure of the number of years a person at birth is expected to live in a healthy condition – are lost in the European Union due to indoor air pollution. That is equivalent to annual road traffic injuries.

The economic costs of indoor air pollution are also staggering, totalling about $200 billion every year.

“We need to integrate our activities to improve indoor air with the activities that lead to the improvement of outdoor air quality so that it will have a positive impact on the indoor air quality,” Wargocki said.

Energy efficiency standards can also harm air quality

Despite existing guidelines to improve indoor air quality, many buildings lack adequate ventilation. This is especially true of energy-efficient buildings built since the oil crisis in the 1970s, which often have reduced air intake and ventilation systems that remove pollutants and reduce moisture. 

In Switzerland,  Minergie energy efficiency standards require the installation of air exchange systems in new buildings to remove pollutants and reduce moisture. Under these standards, opening windows is optional. 

Roger Waeber, head of the indoor pollutants unit at the Swiss government’s Health Protection Directorate, told Health Policy Watch that corners may be cut when old buildings are renovated.  “Most often the air quality in schools in Switzerland is unacceptable,” he said.

Waeber Authorities granting building permits for renovations in public buildings may often not press for a ventilation plan, Waeber said.

“This is an awareness problem. They shouldn’t provide a permit for a school that doesn’t comply with those standards.” 

Waeber added that other people involved in the construction may forget about ventilation systems as they focus on other design issues. Finally, the municipalities themselves may decide that ventilation systems may be too costly to include in a project, without realising their value for human health.

Certification of indoor air quality needed

“It is remarkable to think that this is the first WHO conference (on indoor air pollution)”, WHO Chief Scientist Jeremy Farrar commented at the conference, speaking by video recording from the UN General Assembly in New York. 

“If after the last three years, we do not appreciate the importance of the air we breathe on every part of our lives, then we have really missed an opportunity to move the world forward.”

Farrar emphasised the importance of ethical and social justice considerations in addressing indoor air pollution.  “Whose air is it?” he asked. “What I breathe out will affect you, what I breathe in has come from you.”

In Belgium, Frank Vandenbroucke, deputy prime minister and minister of social affairs and public health, said that recently approved national legislation on indoor air quality has set an agenda for better monitoring, communicating and consulting with stakeholders. 

Vandenbroucke emphasised the need to support scientific research to better understand outdoor and indoor air pollutants. “We need such a knowledge base to define the most efficient regulatory approaches and to use the best existing technologies to reduce the effects of airborne pollutants on our health.”

The minister said that certification of indoor spaces would allow the public to gain confidence in monitoring of pollutants in those areas, and to ensure “transparent, reliable and comprehensive communication” about the air quality.

The pace of change is slow 

Jelle Laverge, an associate professor at Ghent University in Belgium, explained that the current pace of improvements in Europe is projected to be slow.

Projections by the International Network for Information on Ventilation and Energy Performance (INIVE) for the European Commission, forecast that only 20% of existing buildings will have adequate ventilation strategies by 2050.  

Working within the context of Belgium’s new legislation, Laverge set out with scientists to implement a strategy to provide data to occupants of public buildings through informed consent, by installing air monitors in the buildings, which was “a cheap and quick way” for people to check on indoor air quality.

However, the programme underscored certain challenges, such as building managers not being fully qualified to implement the monitoring strategy and even knowing which type of monitors to order for measuring key pollutants in real-time.

“Giving the right people (involved in implementing monitoring) the right kind of information is really challenging. As experts, we typically talk amongst ourselves and expect that everybody understands what we are talking about,” he said.

Indoor air quality should be evaluated in every public building 

For such a programme to be effective, Laverge said, “every owner of a public building needs to make or have someone make a risk assessment regarding indoor air quality of every public space in the building that then needs to go through a certification process. The outcome of that is a label that needs to be shown in every public space.” He said this could include levels of healthy and polluted air in indoor spaces, in terms of the calculated impact of the combined pollutants on health.

Catherine Noakes, professor of environmental engineering for buildings at the University of Leeds in the United Kingdom told Health Policy Watch that indoor air quality isn’t getting the attention it deserves,  even amongst engineers and architects. She said their focus is often more on sustainability and climate impact. 

“I don’t think we have health included in the same way,” Noakes said. “It’s important that air quality, water and all the ways in which our built environment affects our health be part of training.”

Cost vs benefits 

Noakes lamented the “massive gaps” in guidance and regulations, pointing out that the latest European air quality directives will probably be pushed back due to conservative political opposition. ”We don’t have standards on our air quality and we have nothing to benchmark it against. Then we have this lack of awareness and enforcement, as air is invisible. It’s much more tangible to see your energy bills than it is to see the health consequences of the air quality.”

For Wargocki, improving indoor air quality, even marginally, through better ventilation and source control including particle filtration and elimination of other pollutants, could reap huge economic benefits due to superior work performance and better sleep.

“Every action has a cost, but the benefits here are significant, and they are measurable. We really need to have some economic calculations and involve the experts from the economy to take this into account,” he said. 

But for now, most people continue to be unaware of the health benefits. “We spend a lot of money in our houses, buying expensive beds, and invest more money in fitness and healthy food,” he told Health Policy Watch, “I think we should be educating people that clean aid will bring you similar benefits, but it is difficult for them to visualise.”

A panel combining Swiss parliamentarians and scientific experts at the Bern conference agreed that awareness of the health impacts of indoor air pollutants was key to driving concerted action.

Farrar, the WHO’s scientific lead, meanwhile, called for more cooperation. 

“It is crucial that we bring communities together: engineers, architects, urban planners, urban designers, people who work on infection and non-communicable diseases and in many other social sciences, behavioural sciences, as well as people who think about how our schools and transport is designed”, Farrar said.

“That is tough because we are all in our own individual silos. We need to come together and agree on some common language and a culture in the way we work together.” 

Image Credits: Pelle Sten/Flickr, Edna Winti/Flickr, Geneva Health Forum .