At this point in time, you’ve most likely heard of the environmental phenomenon climate change. If you haven’t, you’ve either been living under a rock, or you’re kidding yourself. Despite the current President of the United States not believing in climate change, it is, in fact, very real and is occurring as we speak. Previously dubbed global warming, climate change is responsible for rising temperatures in some regions of the planet. As you may know, these increasing temperatures can be detrimental to human health in regards to heat exhaustion and heat stroke. The health effects of climate change do not stop here.
In order to properly paint the picture of how air pollution impacts public health, one major source of pollution must be considered: wildfires. Wildfire particulate matter (PM) is produced by the burning of trees and other organic materials. Due to its small diameter, PM can both travel long distances from its origin and can penetrate our lungs. Climate change models predict that due to rising temperatures and increasing droughts, the frequency of wildfires will also increase (Dennison et al. 2014; American Lung Association, 2016).
As I’m sure you could guess, air pollution exacerbates preexisting respiratory, such as COPD, and cardiovascular diseases. However, did you know that air pollutants can impair neurological development? Clean air is necessary for brain development (Calderón-Garcidueñas et al., 2014). However, air pollution is not broadly recognized as a factor in neurological development. The effects of air pollution on a child’s brain include the following: inflammation of neurons, cognitive deficits, structural alterations, and diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (Calderón-Garcidueñas et al., 2014).
My intention was not to write another blog post related to Alzheimer’s disease. However, as my research on the neurological consequences of air pollution began to unfold, I had to share what I found. Before this year, I had never really considered what we are doing to this beautiful planet is killing our arguably even more beautiful brains.
Briefly, Alzheimer’s is an age-related neurodegenerative disease. Thus, the older you get, the more likely it is that you’ll develop this disease. Gradual deterioration in behavior and cognition are the main symptoms (Jung et al., 2014). Scientists suggest that the buildup of abnormal structures, formally known as plaques and tangles, are responsible for Alzheimer’s disease symptoms (see the diagram below).
As mentioned above, due to their small size, PM particles are able to penetrate deep into our lungs. How does this affect our brains, you might ask? Once in our respiratory tract, these particles enter the bloodstream. Again, due to its small diameter, PM have the capacity to cross the blood-brain barrier.
The blood-brain barrier (BBB) is a tightly knit unit of cells that select what can and cannot be transported to the brain from normal blood circulation (Rosenberg, 2015). It’s kind of like the “gate-keeper” of the brain (check out the diagram below). PM’s uninvited entrance into the brain can produce a perilous domino effect, leading to serious neurological problems. These problems include disruptions to the blood-brain barrier itself, inflammation of neurons, and neurons deterioration (Calderón-Garcidueñas et al., 2014; Jung et al., 2014). It is these changes that are likely critical to both Alzheimer’s disease onset and progression (Calderón-Garcidueñas et al., 2014).
This effect of air pollution on the blood-brain barrier peaked my curiosity. What role does the BBB play in typical AD onset? While not fully conclusive, studies suggest that aging does affect BBB selectivity, causing an increase in permeability over time. This means that with age, the blood-brain barrier is weakened, allowing in more molecules into the brain than a healthy brain would. The weakening of this important “gate-keeper” can likely contribute to AD (Rosenberg, 2015). Thus, if a weaker BBB can increase AD risk and exposure to air pollutants can exacerbate this weakening process, it is no wonder that air pollution is correlated with Alzheimer’s disease. In one study I found, chronic exposure to PM above current US governmental standards (provided by the EPA) was associated with a 138% increased risk of AD. This is huge! I feel as if society places so much of Alzheimer’s disease on genetics and that these important factors are being unfairly overlooked. We need to treat this planet with care if we, too, want to be healthy.
In my last blog post on Alzheimer’s disease, you read that in order to protect your brain, you should consume more vegetables (check out the previous post if you haven’t seen it!). Of course, eating vegetables and respecting our environment are not mutually exclusive. You can even kill two birds with one stone (that is, reduce your risk of Alzheimer’s disease) by eating sustainably and locally grown vegetables. Not only will your brain thank you for the yummy nutrition from the vegetables themselves, but it will also thank you for doing your part to contribute to a more sustainable agricultural system. Another bonus of eating more vegetables, means you’re eating low on the food chain. Additional methods of contributing to less greenhouse gasses includes carpooling, biking instead of driving, and buying organically (Carbon Offsets to Alleviate Poverty, 2017). Not caring for our planet is not caring for our own personal health, it is a simple as that. So, next time you’re craving a hamburger or drive a short distance you could totally walk (we’ve all done it), think about your brain and choose the greener option.
American Lung Association. 2016. Climate change and lung health. From http://www.lung.org/our-initiatives/healthy-air/outdoor/climate-change/climate-change-lung-health.html
Calderón-Garcidueñas, L., Calderón-Garcidueñas, A., Torres-Jardón, R., Avila-Ramírez, J., Kulesza, R. J., & Angiulli, A. D. (2015). Air pollution and your brain: what do you need to know right now. Primary health care research & development, 16(04), 329-345.
Dennison, P. E., Brewer, S. C., Arnold, J. D., & Moritz, M. A. (2014). Large wildfire trends in the western United States, 1984–2011. Geophysical Research Letters, 41(8), 2928-2933.
Jung, C. R., Lin, Y. T., & Hwang, B. F. (2015). Ozone, particulate matter, and newly diagnosed Alzheimer’s disease: a population-based cohort study in Taiwan. Journal of Alzheimer’s Disease, 44(2), 573-584.
N.a (n.d.). 25+ Tips to Reduce Carbon Footprint from COTAP.org. Cotap.org. Retrieved from http://cotap.org/reduce-carbon-footprint/
Penman, A. (2016). Deforestation and Climate Change. Climateandweather.net. Retrieved from http://www.climateandweather.net/global-warming/deforestation.html
Rosenberg, G. A. (2014). Blood-Brain Barrier Permeability in Aging and Alzheimer’s Disease. The journal of prevention of Alzheimer’s disease, 1(3), 138.