Toxic atmosphere: How life in a metropolis affects health
IN TALK ABOUT THE HARMFUL OF SMOKING OR PROCESSED RED MEAT, there is bound to be an argument that living in a city as a whole is harmful – and to some extent it is. Science is not just talking about the benefits of being in the fresh air for the heart and blood vessels, the quality of sleep and the state of the psyche. Progressive doctors prescribe trips to nature, as if hinting that from time to time we should run into the forest from cars and people. But the question of how harmful life is in the city is difficult to answer unequivocally. Various factors play a role, which no one considered in the aggregate. Let’s try to separate myths from facts and figure out whether it is worth selling my grandmother’s house in the village or is it better to wait anyway.
How air pollution became an epidemic
In 2015, scientists made a frightening statement: more than 3 million people worldwide die each year from air pollution (small particles that can penetrate deep into the lungs) – more than the number of deaths from malaria and HIV / AIDS combined. If humanity does not draw the right conclusions, this figure will reach 6 million by 2050.
The maximum risk, apparently, are children and young people – they have a permanent effect of gases and particulate matter in the air can cause mental health problems. For everyone else, polluted city air threatens dry eye syndrome , an increased risk of diabetes and lung disease . However, the danger may persist even when air pollution remains at a safe level, according to WHO and EPA.
From noise and light to sleep disturbances
Noise outside the window can be very annoying, whether we are talking about a busy highway, a showdown near a stall or an outgoing neighbor’s dog. First of all, it disrupts the structure and subjective quality of sleep, provoking daytime sleepiness and, in the long term, endocrine and metabolic problems. Research also shows that long-term noise pollution is associated with a doubling of the risk of anxiety and depression and blood vessel damage from cortisol exposure. And the World Health Organization notes that noise above a certain level (85 dB) or permanent noise can lead to hearing loss and cognitive impairment. And although the WHO claims that the car makes an average of 70 dB, and the plane takes off by about 120 dB, the figures may be higher – for example, in some parts of the London Underground, the sound reaches 105 dB.
In an effort to draw public attention to the problem, Mimi Hearing Technologies analyzed the levels of noise pollution in fifty cities around the world. Data analysis showed that Guangzhou has the highest noise index, followed by Cairo, Paris, Beijing and Delhi, and the lowest in Zurich. The average hearing level of residents of noisy cities at the time of the study was equivalent to the hearing rate for people ten to twenty years older.
In terms of light, statistics show that people living in illuminated areas with lots of neon signs are more likely to report sleep disturbances. Although a causal relationship has not yet been established, its discovery remains a matter of time, given that urban dwellers are exposed to light 3-6 times more than villagers. On the other hand, overly lit nights cannot be considered the root of all problems. People in cities may sleep poorly for many reasons, including stressful overload, which interferes with normal sleep-wake cycles and increases the risk of inflammation in the body.
Subway survival
If in the morning, cuddling against the glass in a crowded carriage, you think that this is how you can get to death, you are not so far from the truth. A study by the University of Washington found that people who travel significant distances to work are at greater risk of heart disease, diabetes and even cancer. Moreover, if we are talking about the distance between cities, then the risks are likely to increase further.
But even this is sometimes not as scary as trying to imagine the number of microbes living in the subway. There are indeed many of them, and each subway line has its own flora , and during the day the bacteria exchange data to develop antibiotic resistance. Luckily for us, we don’t have to worry too much about this. For safety reasons, it is sufficient to keep your hands away from mucous membranes until they are washed or, if the nose is suddenly impossible to comb back, use a hand sanitizer. There is a so-called hygiene hypothesis – it is that exposure to microbes at an early age teaches the immune system to be more effective. True, it was confirmed only for rural areas: children who grew up on a farm are less likely to suffer from allergies and asthma. Recently, scientists are increasingly saying that the hygienic hypothesis is generally not entirely correct.
City and stress
The available data allow us to conclude that the level of mental problems in cities is slightly higher. A Dutch study on the topic, for example, found that urban dwellers had a 21% higher risk of anxiety disorders and a 39% higher risk of mood disorders. The risk of schizophrenia in people who have grown up in cities, almost two times higher than those who grew up in the country. Experts believe that this is associated with a higher level of stress – but they do not exclude that in rural areas people are simply less likely to report their problems to doctors or do not consider them significant enough. This is indirectly confirmed by the suicide rate: men in rural areas are 54% more likely to commit suicide.
Another reason for the decline in mental health in urban environments may be that the brains of urban dwellers become more susceptible to stress over time . Chronic stress also accelerates the aging process of cells, providing townspeople with more pronounced age-related pigmentation and deeper wrinkles than villagers. The good news is that even small green islands in a bustling city can improve our condition, especially if we include physical activity in the form of a bicycle or skateboard.
How rent affects us
It turns out that renting an apartment can also negatively affect health. To find out, a group of scientists from the Universities of Essex and Bristol decided to look at objective indicators – the level of C-reactive protein associated with infections and inflammation. It turned out that the level of C-reactive protein in the body of apartment owners is lower than that of tenants, and for those who live in separate buildings, in turn, it is lower than that of residents of apartment buildings. Another curious fact: renters who spend a significant portion of their income on rent have lower C-reactive protein levels than renters in general. Perhaps this is somehow connected with a more comfortable location and high quality housing, since you have to pay so much for it.
Real threat: injuries, accidents and icicles
Cities may seem like much more dangerous places than villages, but this is not always the case. City dwellers are 20% less likely to die from an accident, such as falling from a roof or, surprisingly, a car accident. Scientists think it is a matter of the time it takes for emergency services to get to remote areas, and, possibly, more risky behavior of drivers outside the city. As for the magic brick, which can fall on your head at any moment, there is no reason to be afraid of it. Although this sometimes happens , the reported cases are so few that the likelihood is minimal (the risks increase if you work on a construction site). And if it’s worth worrying about some falling objects, it’s about icicles that kill dozens of people in winter .
In some ways, the city may even be useful. Thus, urban dwellers are less likely to exceed the medical norm of weight due to the high standard of living and the quality of nutrition. Old age in the city will also turn out to be more pleasant, since there is no social isolation characteristic of the countryside. Also, urban dwellers may have a better functioning digestive system. Some evolutionists think that the once-excellent lactose tolerance was a beneficial mutation that helped people to leave the nomadic lifestyle and move to cities where farming was the main occupation and dairy products were the main source of food. Finally, there is evidence that residents of large cities are more resistant to tuberculosis and leprosy.
Who is really in danger
While there are risks for all of us living in the city, vulnerable populations suffer the most. We are primarily talking about people living on the street – almost 40% of them have chronic health problems. Although the opinion has grown in society that the homeless are themselves to blame for their situation, in reality the situation is much more complicated and dire. According to Nochlezhka for 2017, the main causes of homelessness are family problems (36%), labor migration (22%) and fraud in real estate transactions (17%). At the same time, 12% of the homeless have a higher education, and 44% have a secondary education. With regard to alcohol abuse, most people start drinking after they are on the street.
In Russia, about five million people are considered homeless , a million of whom are children and 50 thousand of whom live in Moscow. It is especially hard for them in the cold season: in St. Petersburg alone in the winter of 2012-2013, 1,042 people died on the streets . This is a global problem – homelessness is also faced by the “happiest countries in the world,” such as Norway and Denmark . All over the world, according to a UN report , about one hundred million people are homeless.