By Anaya Qamar
Is global warming frying our brains? Recently, experts search for the answer to this new question, noting shifts in how the human brain reacts to environmental change. Climate change is notorious for its increasing impact on our environment and ever changing surroundings. While it significantly changes our current world within natural occurring conditions, it affects our brain by consistently altering the stimuli that we face. Our brain almost entirely revolves around external impact and stimuli to formulate an educated response with the rest of the human body. One key source of the brain’s response lies in the literal atmosphere that surrounds your body- temperature and the air we breathe.
In order to function, the human brain needs a stable environment, to balance the external and complex environmental connections that determine its function. Especially in the developing brains of children and adolescents, environmental stability is crucial to the forming of essential neurons and connections. In recent years, this stability has been seemingly unattainable because of the effects of climate change on Earth’s temperature. In the last one hundred years alone, the Earth’s surface temperature has risen by over 1.3 degrees Celsius, and the ozone layer has experienced thinning from harmful chemicals.
Since the brain only functions optimally in a short range of temperatures, the effects of global warming have impacted brain function significantly. A study from the Yale School of Medicine tested cognitive ability between subjects who were exposed to extreme heat for long periods of time and noticed symptoms including memory loss, decreased focus, and anxiety. Subjects were exposed to temperatures similar to recent heat waves in the southwest United States, western Africa, and the middle east, facing temperatures of up to ninety-five degrees Fahrenheit for multiple hours at a time. Ultimately, change in temperature endangers the development of the human brain, and excess heat leads to cognitive decline of function, which already begins to threaten major areas that currently face heat waves.
While temperature does affect our brains, researchers begin to uncover the larger potential risk factor to brain health: air pollutants. As smoke from forest fires and smog from factory and tailpipe emissions increase, the greenhouse effect traps heat and dirty air behind our atmosphere. Historically, we have viewed air pollution as a cardiovascular and respiratory risk, and never as a brain issue. However, recent data groups issues with air pollution with chronic brain diseases, such as Alzheimer’s and dementia. For example, in Mexico City, an air quality affected region, a conducted study shows that children are more likely to be impacted and show hallmark signs of early Alzheimer’s, such as aggregated neurovascular pathology and subcortical pretangle.
Air pollution can also lead to several neurovascular conditions, including many symptoms found in the previous study. For example, aggregated neurovascular pathology is a sign of neurovascular disease, a brain condition that likely leads to dementia, loss of sensation, and nerve blocks. While experts haven’t pinpointed a specific cause for this condition, studies have proven that areas with higher exposure to pollution and populations affected by heart issues are most heavily impacted. Mexico City has experienced tremendous increases in its air pollution index, some days reaching up to 101-150 on the AQI (air quality index). The brain initially responds to air pollution with “chronic stress”, regulated by the prefrontal cortex, and eventually causing the shrinkage of dendrites, where information is received from other neurons. Chronic stress is the primary cause of nerve blockage and decline in dendrite health. In short, the brain responds to the increasing air pollution that we face in a chain reaction; first with stress in the prefrontal cortex, then with the later effects of Alzheimer disease and neurovascular issues.
Climate change is, above all, a public health crisis, damaging directly our physiology and brain health. As we advocate for political action, technological development, and further study, it is essential that we approach climate change not as a detached environmental threat but as one intimately linked to our wellbeing and livelihood.
