Air Pollutants on Brain Development

Costa, L. G., Cole, T. B., Dao, K., Chang, Y. C., & Garrick, J. M. (2019). Developmental impact of air pollution on brain function. Neurochemistry international, 131, 104580. https://doi.org/10.1016/j.neuint.2019.104580

The air around is a mixture of a variety of compounds such as water vapor, carbon dioxide, oxygen, and nitrogen. Yet this air hasn’t always been made of the same molecules. During periods of the Jurassic, the air contained four times as much carbon dioxide. In the periods before the Industrial Revolution, the air was polluted from particulates produced by tanneries, dried animal manure, and burning wood. But right after the revolution, the burning of fossil fuels such as coal and oil increased the emission of greenhouse gasses - atmosphere-damaging compounds like methane and nitrous oxide - into the air.

As a result of the shifting makeup of the atmosphere, a variety of catastrophic events have resulted. For example, in the 1950s London was struck with an intense smog that resulted in high rates of mortality. As citizens began to inhale the air pollutants, some of those chemicals were able to travel from smell organs to the lungs, where they can cause lung inflammation. At the same time, the pollutants cause throat irritation and tightening of the airways in and out of the lungs. And once they reach the lungs, particulate matter can move to the bloodstream and progress rates of fat buildup within the bloodstream. Heavy metals present in the air can result in the development of lung cancer as they destroy molecules present in DNA and wreak havoc in the body’s internal physiological equilibrium.

When the particulate matter travels through the bloodstream to the brain, the central nervous system (CNS) may develop neurodegenerative diseases that cause the death of neuronal cells. In addition, decreases in cognitive function and the development of depressive symptoms has been a hallmark of heavy pollutant exposure. One study noted that diesel exhaust, a product of automobiles, could alter motor functions, emotional behavior, memory, and result in higher levels of stress.

Environmental insults may have varying results on the CNS depending on its progress in development. After all, cell proliferation, neurotransmitter functions, and neuronal subpopulations vary greatly depending on the CNS’s stage of development. To effectively test the impact of air pollution on the developing CNS, one group of researchers used mice at differing ages and noted that younger mice had more drastic effects after exposure to pollutants such as changes in gene expression and neuroinflammation. In addition, the growth of certain areas of the brain was impacted, resulting in a smaller and less neuron dense brain.

In a human study, nasal exposure to air pollution caused behavioral alterations in children. For example, in Mexico City it was reported that cognitive deficits and hyperactivity served as a byproduct of heavy pollution, resulting in the prognosis of attention-deficit hyperactivity disorder and autism. Another study found that children with intellectual disabilities were more likely to live in an area with high amounts of nitrous oxide and carbon dioxide. It was also noted that living in polluted areas can cause delayed psychomotor development.

Overall, the impact of air pollution on health is clear: exposure to pollutants can result in developmental issues and cause the prognosis of diseases such as cell cancer. Though more research needs to be done on how these issues can be ameliorated, it should be noted that polluted areas should be avoided for the preservation of the body’s overall fitness.

Works Cited:

Causes of climate change. AdaptNSW. https://www.climatechange.environment.nsw.gov.au/causes-climate-change#:~:text=Human%20activity%20has%20rapidly%20increased,gas%20concentrations%20in%20our%20atmosphere.

Pre-industrial. Environmental history. (2018, December 12). https://environmentalhistory.org/ancient/#:~:text=Air%20pollution%20was%20common%20in,infamis%20aer%20(infamous%20air).