Air pollution clouds the mind and makes everyday tasks challenging

Scientists discovered that even brief exposure to high concentrations of PM may impair a person's ability to focus on tasks, avoid distractions, and behave in a socially acceptable manner.

Researchers exposed study participants to either high levels of air pollution -- using candle smoke -- or clean air, testing cognitive abilities before and four hours after exposure. The tests measured working memory, selective attention, emotion recognition, psychomotor speed, and sustained attention.

Publishing their findings today (6 Feb) in Nature Communications, researchers from the Universities of Birmingham and Manchester reveal that selective attention and emotion recognition were negatively affected by air pollution -- regardless of whether subjects breathed normally or only through their mouths.

The experts suggest that inflammation caused by pollution may be responsible for these deficits noting that while selective attention and emotion recognition were affected, working memory was not. This indicates that some brain functions are more resilient to short-term pollution exposure.

Co-author Dr Thomas Faherty, from the University of Birmingham, commented: "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, from the University of Birmingham, commented: "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 and public health measures to combat the harmful effects of pollution on brain health, particularly in highly polluted urban areas."

Cognitive functioning encompasses a diverse array of mental processes crucial for everyday tasks. Selective attention, for example, helps decision-making and goal-directed behaviour, such as prioritising items on your shopping list in the supermarket, while ignoring other products and resisting impulse buys.

Working memory serves as a temporary workspace for holding and manipulating information, vital for tasks requiring simultaneous processing and storage, essential for tasks that require multitasking, such as planning a schedule or juggling multiple conversations.

Socio-emotional cognition, which involves detecting and interpreting emotions in oneself and others, helps guide socially acceptable behaviour. Although these are separate cognitive skills, they work together to enable the successful completion of tasks both at work in other aspects of life.

Overall, the study highlights the need for further research to understand the pathways through which air pollution affects cognitive functions and to explore the long-term impacts, especially on vulnerable populations like children and older adults.

Co-author Professor Gordon McFiggans, from the University of Manchester, commented: "This study shows the importance of understanding the impacts of air pollution on cognitive function and the need to study the influences of different sources of pollution on brain health in vulnerable older members of society."

The study is the first to experimentally manipulate inhalation routes of PM air pollution, providing valuable insights into how different pathways affect cognitive functions. Researchers emphasise the need for further investigation into long-term impacts and potential protective measures.

Globally, air pollution is the leading environmental risk factor to human health, increasing premature mortality. The detrimental impacts of poor air quality on cardiovascular and respiratory systems are widely acknowledged, with links to neurodegenerative conditions such as multiple sclerosis, Alzheimer's disease, and Parkinson's disease.

PM_2.5 is the air pollutant most responsible for human health effects with some 4.2 million deaths attributed to this size of particle alone in 2015. The World Health Organization (WHO) recommends that 24-hour and annual limits are below 15 μg m^?3 and 5 μg m^?3 respectively.