Study Finds Long-Term Brain Health Risks From Growing Up With Solid Fuel Smoke

Study Finds Long-Term Brain Health Risks From Growing Up With Solid Fuel Smoke

(IN BRIEF) A new University of Helsinki study shows that exposure to indoor air pollution from solid fuels during childhood may have lasting effects on cognitive health, with impairments becoming evident decades later. Using data from over 7,000 adults, the research links early exposure to poorer memory and mental functioning in adulthood and highlights biological, socioeconomic and behavioural factors that may intensify these effects. The findings reinforce the importance of clean household energy as a long-term investment in brain health.

(PRESS RELEASE) HELSINKI, 12-Jan-2026 — /EuropaWire/ — University of Helsinki researchers have identified compelling evidence that exposure to indoor air pollution during early childhood may have lasting consequences for brain health, with measurable cognitive effects emerging decades later. The findings suggest that growing up in households that rely on solid fuels such as coal, wood or agricultural waste for cooking and heating can negatively influence cognitive performance well into adulthood.

Despite global progress in clean energy access, nearly 2.4 billion people worldwide still cook using solid fuels, most of them in low-income regions. This practice generates high levels of indoor air pollution, exposing children to smoke and fine particles during critical stages of brain development. According to researcher Xu Zong from the University of Helsinki, the study highlights the long-term risks associated with these early-life conditions, indicating that childhood exposure to polluted indoor air may impair cognitive abilities across the lifespan.

Published in the international journal Social Science & Medicine, the study is the first to directly examine the relationship between early childhood exposure to indoor air pollution and cognitive outcomes in adulthood. Using nationally representative data from more than 7,000 Chinese adults aged 45 and older, the researchers applied advanced machine learning methods to assess long-term cognitive impacts.

The analysis revealed that individuals exposed to indoor air pollution from solid fuels during childhood performed significantly worse on cognitive tests later in life. The strongest associations were found in episodic memory and mental intactness, suggesting that early exposure may contribute to accelerated age-related cognitive decline across multiple domains of brain function.

To better understand the underlying mechanisms, the study examined both biological and socioeconomic pathways. From a biological perspective, childhood exposure was linked to higher rates of overweight and limitations in daily activities in adulthood, factors that can indirectly affect brain health. On the socioeconomic side, early exposure was associated with lower educational attainment and reduced income later in life, both well-established risk factors for cognitive decline.

The research also identified notable differences across population groups. Men, smokers and individuals who regularly consume alcohol appeared particularly susceptible to the long-term cognitive effects of early indoor air pollution exposure. The findings support the hypothesis that inflammation and stress, which may be intensified by tobacco and alcohol use, can amplify neurological damage caused by polluted air.

The study’s authors emphasize that addressing indoor air pollution should be viewed as a long-term investment in cognitive health, not solely as an environmental or respiratory concern. Promoting access to clean household energy sources such as electricity or gas, combined with preventive public health strategies that support healthy behaviours across the lifespan, could play a critical role in protecting brain health for future generations.

Media Contact:

Xu Zong
Tel. 0294123094
xu.zong@helsinki.fi

SOURCE: University of Helsinki