Is it really healthier to live in the countryside?
Whether you’re worried about pollution or stress, you may wonder if leaving your town or city for the countryside may boost not only your happiness, but your health.
But evidence-based research that can help us identify the healthiest environments to live is surprisingly scant. As scientists begin to tease apart the links between well-being and the environment, they are finding that many nuances contribute to and detract from the benefits offered by a certain environment – whether it be a metropolis of millions or a deserted beach.
“What we’re trying to do as a group of researchers around the world is not to promote these things willy-nilly, but to find pro and con evidence on how natural environments – and our increasing detachment from them – might be affecting health and well-being,” says Mathew White, an environmental psychologist at the University of Exeter Medical School.
埃克塞特大学医学院（University of Exeter Medical School）的环境心理学家怀特（Mathew White）说， “我们这群来自世界各地的研究人员不是在毫无章法地倡导什么，而是就自然环境如何影响健康和幸福这个问题，在寻找正反面的证据；人类对环境的态度日益冷漠。”
White and other researchers are revealing that a seemingly countless number of factors determine how our surroundings influence us. These can include a person’s background and life circumstances, the quality and duration of exposure and the activities performed in it.
Generally speaking, evidence suggests that green spaces are good for those of us who live in urban areas. Those who reside near parks or trees tend to enjoy lower levels of ambient air pollution, reduced manmade noise pollution and more cooling effects (something that will become increasingly useful as the planet warms).
一般来说，证据表明绿色空间（green space）对我们这些生活在城市的人是有好处的。居住在公园或树林附近的人往往受益于较少的空气污染、更低的人为噪音和更好的凉爽效应 （随着地球变暖，它会越来越有用）。
Natural spaces are conducive to physical and social activities – both of which are associated with myriad benefits of their own.
Time in nature has been linked to reduced physical markers of stress. When we are out for a stroll or just sitting beneath the trees, our heart rate and blood pressure both tend to go down. We also release more natural ‘killer cells’: lymphocytes that roam throughout the body, hunting down cancerous and virus-infected cells.
Researchers are still trying to determine why this is so, although they do have a number of hypotheses. “One predominate theory is that natural spaces act as a calming backdrop to the busy stimuli of the city,” says Amber Pearson, a health geographer at Michigan State University. “From an evolutionary perspective, we also associate natural things as key resources for survival, so we favour them.”
研究人员已有一些假设，但他们仍在试图确定这是为什么。“一个占主导地位的理论是，自然空间可让城市的繁忙刺激平静下来”。 密歇根州立大学（Michigan State University）的健康地理学家皮尔森（Amber Pearson）说。“从进化论的观点来看，我们也认为自然界是我们赖以生存的重要资源，所以我们喜欢它们”。
This does not necessarily mean that urban denizens should all move to the countryside, however.
City residents tend to suffer from higher levels of asthma, allergies and depression. But they also tend to be less obese, at a lower risk of suicide and are less likely to get killed in an accident. They lead happier lives as seniors and live longer in general.
Although we tend to associate cities with pollution, crime and stress, living in rural locales may entail certain costs as well. Disease-carrying insects and arachnids can detract from the health factor of that otherwise idyllic cabin in Maine, for example.
In other cases, rural pollution poses a major threat. In India, air pollution contributed to the deaths of 1.1 million citizens in 2015 – with rural residents rather than urban ones accounting for 75% of the victims. This is primarily because countryside dwellers are at greater risk of breathing air that is polluted by burning of agricultural fields, wood or cow dung (used for cooking fuel and heat).
Indonesia’s slash and burn-style land clearing likewise causes a blanket of toxic haze that lasts for months and sometimes affects neighbouring countries, including Singapore, Malaysia and Thailand. Meanwhile, smoke pollution from fires lit in South America and southern Africa has been known to make its way around the entire southern hemisphere. (That said, the air in the southern hemisphere is generally cleaner than in the northern hemisphere – simply because there are fewer people living there).
It’s not just developing countries, either: wildfires in the western US are wreaking havoc on air quality, while pollution from fertilizers used on farms are detracting from air quality in Europe, Russia, China and the US.
What about the idea of that pure mountain air? It’s true that black carbon aerosols and particulate matter pollution tends to be lower at higher altitudes. But trying to move above air pollution may cause other issues.
呼吸纯净的山间空气如何？海拔越高，黑碳气溶胶（black carbon aerosols）和颗粒物污染的水平确实会降低。但是如果为了躲避空气污染搬到高处居住，就可能产生其它问题。
While people who live in in places 2,500m or higher seem to have lower mortality from cardiovascular disease, stroke and some types of cancers, data indicate that they also seem to be at an elevated risk of death from chronic pulmonary disease and from lower respiratory tract infections. This is likely at least in part because cars and other vehicles operate less efficiently at higher altitudes, emitting greater amounts of hydrocarbons and carbon monoxide – which is made even more harmful by the increased solar radiation in such places. Living at a moderate altitude of 1,500 to 2,500 meters, therefore, may be the healthiest choice.
On the other hand, there is a strong argument to be made for living near the sea – or at least near some body of water. Those in the UK who live closer to the ocean, for example, tend to have a better bill of health than those who live inland, taking into account their age and socioeconomic status. This is likely due to a variety of reasons, White says, including the fact that our evolution means we are attracted to the high levels of biodiversity found there (in the past, this would have been a helpful indicator of food sources) and that beaches offer opportunities for daily exercise and vitamin D.
Then there are the psychological benefits. A 2016 study Pearson and her colleagues conducted in Wellington, New Zealand found that residents with ocean views had lower levels of psychological distress. For every 10% increase in how much blue space people could see, the researchers found a one-third point reduction in the population’s average Kessler Psychological Distress Scale (used to predict anxiety and mood disorders), independent of socioeconomic status. Given that finding, Pearson says, “One might expect that a 20 to 30% increase in blue space visibility could shift someone from moderate distress into a lower category.” Pearson found similar results in a follow-up study conducted near the Great Lakes in the US (currently in review), as did White in an upcoming study of Hong Kong residents.
住在海边还有心理上的好处。2016年，皮尔森和她的同事们在新西兰惠灵顿进行的研究发现，居住地能看到海景的居民心理困扰水平较低。研究人员发现，人们所能看到的蓝色空间（译注：blue space, 指海水、湖水等）每增加10%，人口平均的凯斯勒心理困扰量表（Kessler Psychological Distress Scale，用于预测焦虑和情绪障碍）就会降低三分之一个点，而且与其社会经济地位无关。皮尔森说，考虑到这一发现”，人们可能会期待，蓝色空间的可见度增加20到30个百分点，就会把一个人从中等程度的心理困扰转化到较低的水平“。皮尔森在美国五大湖（Great Lakes）附近进行的一项后续研究中也发现了类似的结果（目前正在进行评估），在之后进行的一项针对香港居民的研究中，怀特也发现了同样的结果。
Not everyone can live on the coast, however. So Simon Bell, chair of landscape architecture at the Estonian University of Life Sciences and associate director of the OPENspace Centre at the University of Edinburgh, and his colleagues are testing whether restoring neglected bodies of water throughout Europe can help. They are interviewing residents before and after restoration, including at a rundown beach outside of Tallinn, Estonia and an industrial canal near a Soviet bloc-style apartment complex in Tartu, also Estonia, among other places in Spain, Portugal, Sweden and the UK.
然而，并不是每个人都能住在海边。贝尔（Simon Bell）是爱沙尼亚生命科学大学（Estonian University of Life Science）的景观建筑学首席教授以及爱丁堡大学（University of Edinburgh）开放空间中心（OPENspace Centre）的副主任，他和他的同事正在调查在欧洲修复被遗弃的水体是否有帮助。他们在修复前后采访当地的居民。修复的水体包括爱沙尼亚首都塔林（Tallinn）外一个破旧的海滩、爱沙尼亚第二大城市塔尔图（Tartu）一幢苏式公寓大楼附近的工业运河，以及西班牙、葡萄牙、瑞典和英国的一些地方。
The team’s second analysis of nearly 200 recently redeveloped water sites will allow them to tease out how factors such as climate, weather, pollution levels, smells, seasonality, safety and security, accessibility and more, influence a given water body’s appeal. The ultimate goal, Bell says, is to find “what makes a great blue space.” Once the results are in, he and his colleagues will develop a quality assessment tool for those looking to most effectively restore urban canals, overgrown lakes, former docklands, rivers and other neglected blue spaces to make residents’ lives better.
Still, when it comes to wellbeing, researchers do not know how lakes compare to oceans or how rivers compare to seas. Nor have they compared how beaches in, say, Iceland measure up to those in Florida. What they do know is that complex factors including air and water quality, crowding, temperature and even high and low tides affect how something as seemingly simple as a visit to the beach can influence us.
“There might be a million other important things besides weather and daylight that influence someone in Hawaii versus Finland,” White says.
In terms of health, data also suggest that, counterintuitively, people who live in more intermittently rather than regularly sunny places – Vermont and Minnesota in the US, for example, and Denmark and France – tend to have higher rates of skin cancer, likely because sunscreen is not part of daily routines.
Just as some green and blue spaces may be more beneficial than others, researchers are also coming to realize that the environment’s influence on well-being is not evenly distributed.
People living in lower socioeconomic conditions tend to derive more benefits from natural spaces than wealthy residents, White says. That’s likely because richer people enjoy other health-improving privileges, such as taking holidays and leading generally less stressful lives – a finding with important real-world implications. “Here in the UK, local authorities have a legal obligation to reduce health inequalities. So one way to do that is to improve the park system,” White says. “The poorest will benefit the most.”
It’s also important to point out that simply moving to a relatively pristine coast or forest will not solve all of our problems. Other life circumstances – losing or gaining a job, marrying or divorcing – have a much greater impact on our health. As White puts it, no matter what environment you’re in, “It’s more important to have a house than to be homeless in a park.”
Bell adds that proximity to nature actually tends to rank low on people’s lists of the most important factors for selecting a place to live, after things like safety, quietness and closeness to key locations like schools and work. But while the benefits of green and blue spaces should not be overplayed on an individual level, they are important for the scale at which they work.
And even so, one takeaway seems obvious: those living in a clean, oceanside city with ready access to nature – think Sydney or Wellington – may have struck the jackpot in terms of the healthiest places to live.