Air Pollution Exposure Reduces Ability to Concentrate on Everyday Tasks: Study

Short-term exposure to air pollution makes people less able to focus on routine tasks or interpret emotions, a new study by researchers from the Universities of Manchester and Birmingham has found.

The scientists discovered that people who were even briefly exposed to high levels of particulate matter (PM) could find it harder to avoid distractions and act in a manner that was socially acceptable, a press release from the University of Birmingham said.

“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,” said co-author of the study Dr. Thomas Faherty, a postdoctoral researcher with the University of Birmingham’s School of Geography, Earth and Environmental Sciences, in the press release.

The research team exposed participants to either clean air or high air pollution levels caused by candle smoke, testing their cognitive abilities both before exposure and four hours later.

The test measured selective attention, working memory, psychomotor speed, sustained attention and emotion recognition.

The findings revealed that air pollution negatively affected emotion recognition and selective attention, regardless of whether the subjects breathed normally or just through their mouths.

“They were worse at perceiving whether a face was fearful or happy, and that might have implications for how we behave with other people,” Faherty said, as The Guardian reported. “There are associative studies looking at short-term air pollution and incidents of things like violent crime, especially in U.S. cities.”

The study, “Acute particulate matter exposure diminishes executive cognitive functioning after four hours regardless of inhalation pathway,” was published in the journal Nature Communications.

“Recent evidence suggests that short-term exposure to particulate PM air pollution can temporarily impair several key cognitive functions, including selective attention, switch costs (which are relevant to multitasking), decision-making, processing speed, functional connectivity, and even global cognitive functioning,” the authors of the study wrote.

The findings suggested that inflammation triggered by pollution could be to blame for the deficits, but noted that working memory was not affected. This indicated that some human brain functions were more resilient to short-term PM exposure.

“Poor air quality undermines intellectual development and worker productivity, with significant societal and economic implications in a high-tech world reliant on cognitive excellence,” said study co-author Francis Pope, an environmental scientist and professor of atmospheric science at the University of Birmingham, in the press release. “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 involves a variety of mental processes used to complete everyday tasks. For example, selective attention assists with goal-directed behavior and decision-making, such as prioritizing shopping list items at the supermarket, while ignoring items not on the list and resisting impulse buys.

“Participants exposed to air pollution were not as good at avoiding the distracting information,” Faherty said, as reported by The Guardian. “So that means in daily life, you could get more distracted by things. Supermarket shopping is a good example… it might mean that you get more distracted by impulse buys when you’re walking along supermarket aisles because you’re not able to focus on your task goals.”

Working memory is a place to hold and manipulate information, which is essential for tasks that need simultaneous storage and processing — those that require multitasking, like juggling multiple conversations or planning a schedule.

Socio-emotional cognition involves the detection and interpretation of emotions both in oneself and other people, helping to guide socially acceptable behavior.

Though these are distinct cognitive skills, they work in tandem to allow us to successfully complete tasks at work and in other areas of life.

The study highlights the necessity of additional research to understand how air pollution impacts cognitive function, as well as to explore its long-term effects, particularly on vulnerable populations like older adults and children.

“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,” said co-author Professor Gordon McFiggans, a professor of atmospheric science at University of Manchester, in the press release.

Air pollution is the biggest environmental risk factor for human health worldwide. The detrimental effects on respiratory and cardiovascular systems from exposure to poor air quality are well-known, with links to Alzheimer’s and Parkinson’s diseases, multiple sclerosis and other neurodegenerative conditions.

“The study was done on a clinically healthy adult population, which means that they were of good health and had no clinical respiratory or neurological problems… certain other groups might be more vulnerable to effects,” Faherty said, as The Guardian reported.

The air pollutant PM2.5 is the most responsible for negative impacts on human health, having caused approximately 4.2 million deaths in 2015.

The new study was part of a broader project that will test impacts of different pollution sources, which researchers hope will inform public health and policy measures in the future.

“The larger project… looks at different sources of pollutants, which are more common. So like cooking emissions and wood burning and car exhaust and cleaning products, to kind of tease out whether we can kind of push policy in a certain direction,” Faherty said, as reported by The Guardian. “If we know that cleaning products are causing most of these issues that I’m describing, then we can kind of push on policy to fix the things that are wrong based on the source rather than what we can just measure in the air after the fact.”