The choice to live in a big city or the countryside comes down to the individual. Age, income level, personal interests, disease risk factors, and long-term goals are among the many factors that determine the most suitable environment for a person to thrive in. Nevertheless, studies have observed certain trends when examining those of us who have chosen to live in concrete jungles.

Stop-and-go traffic and high-rise buildings can significantly increase our exposure to air pollution, according to David Newby, a professor of cardiology at the University of Edinburgh, Scotland. 

"More remote rural areas have half the concentration of pollution of urban areas," he said.

Airborne particles and pollutants (including nitrogen dioxide and sulfur dioxide) have been linked to an increased risk of lung cancer, type 2 diabetes, asthma, premature death, and more.

And while most of us understand the threat of air pollution, the impact of noise pollution is relatively underestimated. Simply living by a road can expose people to higher levels of transport and urban city noise, disturbing sleep quality at night. Artificial light exposure is also being studied as a major factor in poor sleep among those who live in the city.

Younger individuals may be vulnerable to the impact of noise pollution with regards to their attention span.

"[Children] have found that tasks such as reading, attention span, problem-solving and memory appear to be most affected by exposure to noise," said Dr. Eoin King, author of "Environmental Noise Pollution."

But on the subject of mental health, it is much harder to draw clear conclusions. Some people may find their mental health suffers due to various aspects of the big city life. It has been suggested the presence of large crowds, combined with the claustrophobic nature of public transport and small living spaces, can increase production of the stress hormone cortisol.

For example, some people have reported experiencing higher stress and panic attacks when using the London Underground. Studies have also found a higher incidence of anxiety and a 39 percent increased risk of mood disorders among city-dwellers. But many people also report feeling happier and more content when living in a city. 

Dr. Andrea Mechelli, a neuroscientist at King’s College London, stated people from minority groups (such as LGBT) may have better chances of meeting like-minded people in progressive cities, experiencing lesser isolation and discrimination.

"Another example is that in cities you have more job opportunities, and jobs are key to mental health," he added.

Those who live in rural areas are also more likely to face barriers in access to healthcare. Children who grow up in such areas are less likely to receive information and advice regarding exercise, diet, risky behaviors etc. compared to children growing up in metropolitan areas, one report revealed.