Air Pollution Found To Radically Increase Stress Hormones And Alter Metabolism: Is This Why So Many City Dwellers Have Health Issues?

Photo – JuergenPM – pixabay.com

Living in the city has a lot of benefits – you have better access to most things, like healthcare, transportation, and plenty of leisure activities. The World Bank estimates that four billion people were living in urban areas by 2016, leaving rural areas with less than half of the world’s population – roughly 44 percent compared to the urban population at 56 percent. However, urban living has a lot of drawbacks too. Because of the spotlight on stress and how it affects health, recent studies have focused on the reason why city dwellers have poorer health compared to their rural counterparts. ^[1][2]

A study was published in 2017 in Circulation, a journal by the American Heart Association, that focused on particulate matter exposure (a.k.a. air pollution) in cities and how it relates to stress hormone levels. The experimental study was conducted by Li, et. al. from the University of Shanghai in China and theorizes that the level of air pollution found in urban areas greatly affected a person’s health and his/her risk for various morbidities like heart disease and diabetes. ^[3]

The researchers included 60 healthy college students living in dormitories in Shanghai, China and placed air purifiers in their living spaces. There were initially 34 students in the experimental group (who received working air purifiers) and 26 students in the control group (who received sham air purifiers, a.k.a. non-working air purifiers). 31 students from the experimental group and 24 students from the control group were able to complete the first part of the study. These 55 students were involved in the crossover, wherein the air-purifiers were switched around, meaning the experimental group then received the non-working purifiers and the control group received the working ones.

After nine days, the researchers collected their data and found that stress hormones, specifically cortisone, cortisol, epinephrine, and norepinephrine were all higher during periods of “fake” air purification compared to when the students received the real air purifiers. For every 10 nanogram per cubic meter increase in particulate matter, stress hormones increased by as much as 11 percent (for norepinephrine) and as little as 4 percent (for cortisone). With increases in stress hormones released by the body in relation to air pollution, the researchers concluded that living in the city could potentially increase your risk for health problems in the future.

A similar study was done a few years back in 2011 that also focused on urban living and stress. Lederbogen, et. al. found that living in the city negatively affected neurological health, causing mood and anxiety disorders – and even an increased risk for schizophrenia. Mental disorders have often been associated with a person’s social interaction (or lack thereof). The researchers used magnetic resonance imaging (MRIs) to assess the brain’s reaction to living in urban areas. They found that the amygdala, the part of the brain responsible for negative affect and stress, was highly active in people currently living the city – and that this high activity was specific to the amygdala since no other parts of the brain structures were affected compared to the study’s control group. The study concluded a strong link between the urban environment and a person’s mental health across his or her lifespan, and that living in the city was a big risk factor in developing mental health problems. ^[4]

These studies are only two out of the thousands that have been conducted in the recent years on how stress affects our health. Often, we don’t get a say at where we live, especially if your work or school is in the city – but scoffing at the idea of a weekend getaway in the countryside might do more harm than good. Don’t forget to take a breather every now and then and find ways to relax – in or out of the city.

Further Reading:

US Air Pollution Still Kills Thousands Every Year – Study Concludes

How To Make Your Own DIY Low-Tech Air Purifier

List Of Plants Found By NASA To Purify Indoor Air Naturally Plus 8 Top Aromatic Indoor Plants