Could City be Affecting our Health and Longevity?
Living in a large town or city, or by a busy road, has been linked with an increased risk of developing heart disease.
Air pollution, which is often caused by vehicle emissions, factories and chimneys, is a serious problem in built-up areas. In the UK, levels of toxic nitrogen dioxide gas in the air are generally within the recommended safe level of 40 parts per million (ppm). Air pollution has been steadily decreasing across the UK since the early 90s, but big spikes in air pollution do occur from time to time1. Slow-moving traffic on busy roads can breach the safe limit, with some streets in London recording levels of up to 93 in the past.
The recommended safe level of nitrogen dioxide in the air is still high enough to cause increased mortality and disease. A study from Utrecht University in the Netherlands found that for every 5ppm of nitrogen dioxide in the air, a person's chances of dying from natural causes raises by 7%2. Limit your exposure to polluted air by taking a less congested route to work and avoiding high-emissions areas as much as possible.
Walking through a forest, breathing in the fresh air and admiring the wildlife around you is a great way to relax. Some research has suggested that being in nature could be beneficial to your heart, even if you're not moving around or being active. Living in close proximity to green spaces like parks, forests and allotments has been linked with better heart health. It was found to reduce the risk of a person developing coronary heart disease, cardiovascular disease and some types of stroke. Spending time in nature could even extend your life3.
Nobody's entirely sure why this is. It may be down to the stress-reducing properties of being immersed in nature. When we're surrounded by plants and vegetation, we tend to produce less of the stress hormones cortisol and adrenaline. Spending just 20 minutes in nature can trigger a significant decrease in stress. These health-improving effects are more pronounced in women than men, according to a 2019 study4. It could also be because of the better air quality, or a combination of these factors and others.
DEFRA, the government department in charge of the UK's air quality, publishes a Daily Air Quality Index. They forecast air pollution in all regions of England, Wales, Scotland and Northern Ireland for up to five days into the future. Their website rates air quality on a 1 to 10 scale and they provide additional advice for people with underlying health conditions5.
To improve your health and potentially extend your life, increase the amount of time you spend in nature and avoid breathing in polluted air as much as possible.