Burning Candles at Home Could Heighten Dementia Risk, Warn Scientists
Households that regularly light candles have been issued a stark health warning following groundbreaking research that suggests even brief exposure to candle emissions could impair cognitive function and potentially contribute to dementia development. A comprehensive study from the University of Birmingham has examined how minimal pollution levels from common household sources affect mental processes essential for daily life.
Immediate Cognitive Impairment Following Candle Exposure
The research findings revealed that participants tested after candle burning experienced significant cognitive impairment across multiple measures. According to the study published in Nature Communications, brief exposure to particulate matter air pollution, including emissions from candles, compromises the ability to interpret emotions and maintain concentration on routine tasks.
Researchers discovered that even momentary exposure to elevated PM concentrations may undermine an individual's capacity to concentrate, resist distractions, and maintain socially appropriate behaviour. This could affect everyday activities such as weekly grocery shopping, where decision-making and focus are crucial.
Experimental Design and Key Findings
Study participants were exposed to either elevated air pollution levels generated by candle smoke or filtered air, with cognitive assessments conducted before exposure and four hours afterwards. The evaluations measured:
- Working memory
- Selective attention
- Emotion recognition
- Psychomotor speed
- Sustained attention
The research demonstrated that air pollution negatively impacted selective attention and emotion recognition regardless of whether participants breathed normally or exclusively through their mouths. Interestingly, while these functions were compromised, working memory remained unaffected, suggesting certain cognitive abilities demonstrate greater resistance to brief pollution exposure.
Medical Experts Voice Concerns
Dr Thomas Faherty from the University of Birmingham stated: "Our study provides compelling evidence that even short-term exposure to particulate matter can have immediate negative effects on brain functions essential for daily activities, such as doing the weekly supermarket shop."
Co-author Professor Francis Pope added: "Poor air quality undermines intellectual development and worker productivity, with significant societal and economic implications in a high-tech world reliant on cognitive excellence. Reduced productivity impacts economic growth, further highlighting the urgent need for stricter air quality regulations."
Speaking on his podcast No Appointment Necessary, Dr Amir Khan recently emphasised that some people might be exposing themselves to health risks by burning candles too frequently indoors. The GP explained: "Burning one candle isn't going to kill you, but over time, if you are burning lots of candles many days of the week, they give off volatile oxiditive compounds. These are tiny particles that you can breathe in, and they can cause inflammation in your body."
Understanding Cognitive Function and Pollution Impact
Cognitive function encompasses a wide range of mental processes essential for daily life, including:
- Decision-making and goal-focused behaviour
- Working memory for multitasking activities
- Socio-emotional cognition for recognising and understanding emotions
These distinct cognitive abilities function together to facilitate successful task completion in both workplace and domestic settings. The inflammation triggered by pollution particles could be behind the impairments observed in the study, according to researchers from the Universities of Birmingham and Manchester.
Call for Further Research and Public Health Measures
The research marks the first experimental manipulation of PM air pollution inhalation routes, offering crucial insights into how various pathways influence cognitive abilities. Scientists stress the importance of additional research into long-term consequences and possible preventative strategies, particularly for vulnerable groups such as children and elderly people.
Co-author Professor Gordon McFiggans from the University of Manchester said: "This study shows the importance of understanding the impacts of air pollution on cognitive function and the need to study the influences of different pollution sources on brain health in vulnerable older members of society."
Worldwide, air pollution stands as the primary environmental threat to human health, contributing to early deaths and connections to degenerative brain conditions including multiple sclerosis, Alzheimer's disease, and Parkinson's disease. PM2.5 represents the air pollutant most accountable for adverse health outcomes, with approximately 4.2 million fatalities linked to this particle size in 2015 alone.
The World Health Organization advises that 24-hour and yearly thresholds should remain beneath 15 μg m3 and 5 μg m3 respectively, highlighting the global scale of air quality concerns that now extend to common household practices like candle burning.
