A recent study conducted by researchers from the University of British Columbia and the University of Victoria reveals that even common levels of traffic pollution can impair human brain function within a few hours. The first in the world study investigated the acute effects of diesel exhaust exposure on the functional connectivity of the brain in 25 healthy individuals. Functional magnetic resonance imaging (fMRI) was used to measure the functional connectivity of various brain regions before and after exposure to either clean air or diesel exhaust. The study found that acute exposure to diesel exhaust significantly impaired functional brain connectivity in areas related to cognition, memory, and decision-making. The results of this research are noteworthy since they indicate that brief exposure to diesel exhaust, at levels typically observed in cities, can lead to impaired cognitive performance and heightened stress responses in healthy people.
The air quality index (AQI) of Kathmandu while I write these words is at 177, which is considered as ‘unhealthy’, a level at which even healthy people will have difficulty breathing. The PM2.5 concentration in Kathmandu was currently 14.8 times the WHO annual air quality guideline value. PM2.5 are tiny pollutant particles in the air which is considered most hazardous to health, reduces visibility and cause the air to appear hazy when levels are elevated. Although the PM2.5 concentration in Kathmandu valley is at an elevated level throughout the year, it reaches at an extreme during the winter season when temperatures are low and winds are calm. This is evident by the constant layer of smog hovering above the city particularly during the chilly mornings. The biggest emitter of PM 2.5 pollutant are vehicles in Kathmandu valley along with other contributors such as refuse burning, brick kilns and power generation. The rise in the pollution level has led to increase in various chronic illnesses related to heart and lungs with 17,900 deaths in Nepal being attributed to PM2.5 in the year 2019.
As the city is undergoing massive economic transformation and rapid urbanization, the pollution level in Kathmandu valley has been continuously growing. Therefore, it is imperative that the citizens will involuntarily breathe bad quality air that is extremely harmful to health. As population of Kathmandu valley continues to rise, so will the number of gasoline vehicles resulting in the rise of vehicular emissions. Hence, exposure to such harmful particles such as PM 2.5 during urban commute will severely impact brain function and cognition along with adversely impacting other vital human organs.
Necessary precautionary measures are warranted from citizens to avoid being exposed to harmful air pollutants such as vehicular emissions. More importantly, policies surrounding pollution and public health are to be reconsidered.