Written by Adrian McConnell, Chief Executive, CO Research Trust
When I joined policymakers, scientists, and public health experts from Azerbaijan, Georgia, Kazakhstan, and Turkey, amongst others in Istanbul, the agenda initially centred on outdoor air pollution. However, as the discussions unfolded, a quieter but equally dangerous problem emerged: indoor air quality, specifically the risk posed by carbon monoxide (CO).
Carbon monoxide is one of the most dangerous indoor pollutants precisely because it cannot be detected by human senses. Produced through incomplete combustion of fuels such as gas, coal, and wood, it is colourless, odourless, and potentially fatal.
Once inhaled, it binds to haemoglobin in the bloodstream, preventing oxygen from reaching vital organs. Even moderate exposure can cause headaches, dizziness, and fatigue; higher concentrations can lead to poisoning and death.
What became clear in Istanbul is that while the sources differ from country to country, carbon monoxide is a common risk. And the specifics are remarkably familiar.
Azerbaijan: Urban Energy and Domestic Exposure
In Baku, rapid urban growth and increasing energy demand have expanded reliance on gas-fired heating and cooking appliances. While natural gas is often considered a cleaner fuel than coal or biomass, poorly maintained boilers, blocked flues, and inadequate ventilation can still produce dangerous carbon monoxide levels.
Urban density also means that outdoor pollution can infiltrate buildings, adding to the indoor burden. Carbon monoxide poisoning incidents linked to heating appliances remain a recognized risk across many gas-dependent housing systems, highlighting the importance of appliance maintenance, ventilation standards, and CO detection technologies.
Georgia: Heating Practices and Vulnerable Classrooms
Delegates from Georgia highlighted the continued use of wood-burning stoves in schools and homes, particularly in rural areas. Research examining Georgian kindergartens found that buildings heated with wood stoves experienced significantly higher particulate pollution levels compared with those using central heating systems.
These stoves also create conditions where incomplete combustion can generate carbon monoxide. During winter months, when buildings remain closed to conserve heat, indoor pollutants can accumulate to levels that affect children’s respiratory health and cognitive performance. The challenge in Georgia therefore combines energy access, heating technology, and ventilation practices.
Kazakhstan: Winter Smog and Indoor Accumulation
In Almaty and other industrial centres of Kazakhstan, winter temperature inversions trap pollution from coal-based heating and industry. This outdoor pollution often penetrates buildings, but the indoor environment can worsen the problem.
Homes are tightly sealed during long heating seasons to conserve energy. When combustion appliances operate in these conditions, carbon monoxide can accumulate indoors. The result is a double burden: outdoor smog entering buildings while indoor heating sources add additional pollutants.
International development institutions have increasingly highlighted residential heating as a major contributor to both air pollution and public health impacts in Kazakhstan.
Turkey: Urban Living and Everyday Combustion
Hosting the meeting in Istanbul highlighted Turkey’s own indoor air quality challenges. In many urban homes, cooking and heating rely on gas appliances, while some households still use coal or biomass stoves during colder months.
Without effective ventilation, such as extractor fans or properly functioning flues; combustion processes can generate carbon monoxide indoors. Combined with pollution from traffic infiltrating dense residential areas, this creates environments where indoor and outdoor air policies must work together.
A Shared Regional Challenge
Despite differences in climate, housing, and energy systems, the countries represented in Istanbul shared several common realities:
Combustion appliances remain central sources of indoor pollution
Carbon monoxide is the most dangerous pollutant because it is invisible and odourless
Poor ventilation amplifies exposure risks
Vulnerable populations (IE children, older adults, and people with chronic illness) face the greatest health impacts
The solutions therefore require cross-sector cooperation, linking public health policy with housing regulations, energy transitions, and consumer awareness.
Lessons from the United Kingdom and the United States
These challenges are obviously not unique to the Caspian and Black Sea region.
In the United Kingdom, carbon monoxide poisoning continues to occur each year due to faulty boilers, blocked flues, and other domestic fuel-burning appliances. Government data indicate that around 20 people die annually from accidental carbon monoxide poisoning, while many more require hospital treatment.
Regulations requiring carbon monoxide alarms in homes have been introduced across much of the UK, reflecting recognition that detection can save lives when prevention fails.
In the United States, guidance from the U.S. Environmental Protection Agency highlights carbon monoxide as one of the most significant indoor pollutants affecting health. Americans spend roughly 90 percent of their time indoors, meaning exposure to combustion gases from gas stoves, furnaces, fireplaces, and portable generators can have major health consequences if appliances are poorly ventilated or maintained.
These experiences illustrate an important lesson: economic development alone does not eliminate indoor air risks. Even in advanced economies with modern housing and infrastructure, carbon monoxide remains a persistent hazard without proper safeguards.
Turning Evidence into Action
The discussions in Istanbul reinforced a simple but powerful message: carbon monoxide must become central to indoor air quality policy.
This means:
- Ensuring safe design and maintenance of fuel-burning appliances
- Strengthening building ventilation standards
- Expanding carbon monoxide monitoring and alarm use
- Increasing public awareness of indoor air risks
Clean air policies have traditionally focused on what we breathe outside. Yet the air inside our homes, schools, and workplaces often matters just as much, if not more.
Carbon monoxide is invisible, but its impact is not. By recognising it as a shared regional challenge, countries across Eurasia, and beyond; can work together to ensure that the places where people spend most of their lives, are also safe and healthy places.
* After singing They Might Be Giants “Istanbul (not Constantinople)” to myself for three days this blog could only have one title!