The next time you feel like you are losing your mind while being stuck in a traffic jam, you probably might be right – in the literal sense.Ā
A study titled āThe impact of exposure to air pollution on cognitive performanceā showed that chronic exposure to dirty air, such as inhaling carbon emissions from traffic, can lead to significant reductions in human intelligence.Ā
The researchers concluded that the decrease in an individualās IQ is equivalent to losing a year of education. Furthermore, students taking a test on days whereby the air pollution index is high, could potentially face a drop in performance levels.
Automobile usage has been increasing following the rise in urbanization and economic growth across cities worldwide. This has resulted in the escalation of vehicular emissions, which can be extremely deadly as they fill the streets with exhaust and toxic particles like soot and carbon monoxide (Fig 1). Transportation emits more than half of nitrogen oxides in our air, and is a major source of global warming. Despite only comprising 5% of vehicles on the road, heavy-duty vehicles are responsible for more than 25% of carbon emissions. These fine particles in polluted air can enter the brain via the nose and bloodstream.Ā
Fig 1: An infographic depicting the sources from which each vehicle releases pollutants (Source: EEA, 2019)
Prolonged exposure to such particulate matter has negative impacts on our cognitive performance, and might in fact be making us dumber. Cognitive impairment refers to when people experience trouble remembering, learning new things, concentrating, or making decisions that affect their everyday life. It could increase oneās risk of developing Alzheimerās disease or dementia.
Researchers at the International Food Policy Research Institute (IFPRI) examined data collected from the national China Family Panel Studies longitudinal survey, which mapped cognitive test scores of 32,000 people between 2010 and 2014 against their exposure to short- and long-term air pollution. The team discovered that high air pollution exposure was correlated with a decrease in verbal and math scores (see Fig 2). The effect was intensified among older, less educated men. It is evident that pollution impacts people unequally, usually hitting the more vulnerable members of society the hardest.
Fig 2: Air pollution levels and mean verbal and math test scores were shown to exhibit an inverse relation (Source: Zhang, Chen & Zhang, 2018)
I am appalled by the negative effects air pollution has on the human body. It can indirectly affect us even in ways we cannot visualize; its impacts only manifest in the long run. This calls for an urgent need to devise strategies to help the world move towards net zero emissions, especially in the transportation sector. After all, I agree with physicist Stephen Hawking who once said that pollution coupled with human greed and stupidity are still the biggest threats to humankind.
Check out this video explaining how air pollution makes us dumber.
Bibliography
EEA. (2019, December 10). Vehicle Emissions and Efficiency. Retrieved from European Environment Agency: https://www.eea.europa.eu/media/infographics/vehicle-emissions-and-efficiency-1/view
EPA. (2017). Fast Facts: U.S. Transportation Sector Greenhouse Gas Emissions. New York: Office of Transportation and Air Quality.
EPA. (2023, January 4). Smog, Soot, and Other Air Pollution from Transportation. Retrieved from United States Environmental Protection Agency: https://www.epa.gov/transportation-air-pollution-and-climate-change/smog-soot-and-other-air-pollution-transportation
Griffiths, J. (2018, August 28). Air pollution is making us dumber, study shows. Retrieved from CNN Health: https://edition.cnn.com/2018/08/27/health/air-pollution-cognitive-abilities-intl/index.html
Zhang, X., Chen, X., & Zhang, X. (2018). The impact of exposure to air pollution on cognitive performance. Psychological and Cognitive Sciences, 115 (37): 9193-9197.
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