A new study suggests that growing up in households reliant on solid fuels such as coal, wood and plant waste may have lasting consequences for brain health, with measurable cognitive impairment emerging decades later.
Across much of the world, particularly in low-income countries, billions of people continue to depend on solid fuels for cooking and heating.
A a result, children are exposed to high levels of indoor air pollution, during critical stages of brain development.
Xu Zong, a researcher at the University of Helsinki said: ‘Nearly 30% of the global population, roughly 2.4 billion people, still cook without clean fuels. Our findings indicate that growing up in a smoke-filled household may impair brain health and cognitive abilities throughout life.’.
The study is the first to examine the long-term relationship between early childhood exposure to indoor air pollution and cognitive performance in adulthood.
The researchers analysed nationally representative data from more than 7,000 Chinese adults aged 45 and older, applying advanced machine-learning techniques to assess cognitive outcomes.
The results show that individuals exposed to indoor air pollution from solid fuels during childhood performed significantly worse on cognitive tests later in life.
Zoing explains: ‘The association remained strong in two key areas of cognitive function: episodic memory and overall mental health. This indicates that early exposure may accelerate age-related cognitive decline in several areas of brain function.’
The researchers identified two main pathways through which early exposure may affect cognition: biological and socioeconomic.
Biologically, childhood exposure was linked to higher rates of being overweight and greater limitations in daily activities, factors that can indirectly impair brain health over time.
Socioeconomically, those exposed were more likely to have lower educational attainment and income in adulthood – both established risk factors for cognitive decline.
The study also found a gender difference. Men, smokers and regular alcohol users were particularly vulnerable to the harmful cognitive effects of early exposure, suggesting that inflammation and stress linked to tobacco and alcohol use may intensify neurological damage caused by air pollution.
Zong said: ‘Our study emphasises that early exposure to air pollution affects later cognitive health through both biological and social pathways. That is why public health efforts should combine clean energy initiatives with preventive strategies that support lifelong health and positive behaviours.
‘Switching to cleaner fuels, such as gas or electricity, is not merely an environmental or respiratory health measure. It is also an investment in long-term cognitive wellbeing that could safeguard brain health for future generations.’
The full research can be read here.
Photo: Fatima Yusuf / Unsplash
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