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.
埃克塞特大學醫學院（University of Exeter Medical School）的環境心理學家懷特（Mathew White）說， “我們這群來自世界各地的研究人員不是在毫無章法地倡導什么，而是就自然環境如何影響健康和幸福這個問題，在尋找正反面的證據；人類對環境的態度日益冷漠。”
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).
一般來說，證據表明綠色空間（green space）對我們這些生活在城市的人是有好處的。居住在公園或樹林附近的人往往受益于較少的空氣污染、更低的人為噪音和更好的涼爽效應 （隨著地球變暖，它會越來越有用）。
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.”
研究人員已有一些假設，但他們仍在試圖確定這是為什么。“一個占主導地位的理論是，自然空間可讓城市的繁忙刺激平靜下來”。 密歇根州立大學（Michigan State University）的健康地理學家皮爾森（Amber Pearson）說。“從進化論的觀點來看，我們也認為自然界是我們賴以生存的重要資源，所以我們喜歡它們”。
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.
呼吸純凈的山間空氣如何？海拔越高，黑碳氣溶膠（black carbon aerosols）和顆粒物污染的水平確實會降低。但是如果為了躲避空氣污染搬到高處居住，就可能產生其它問題。
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.
住在海邊還有心理上的好處。2016年，皮爾森和她的同事們在新西蘭惠靈頓進行的研究發現，居住地能看到海景的居民心理困擾水平較低。研究人員發現，人們所能看到的藍色空間（譯注：blue space, 指海水、湖水等）每增加10%，人口平均的凱斯勒心理困擾量表（Kessler Psychological Distress Scale，用于預測焦慮和情緒障礙）就會降低三分之一個點，而且與其社會經濟地位無關。皮爾森說，考慮到這一發現”，人們可能會期待，藍色空間的可見度增加20到30個百分點，就會把一個人從中等程度的心理困擾轉化到較低的水平“。皮爾森在美國五大湖（Great Lakes）附近進行的一項后續研究中也發現了類似的結果（目前正在進行評估），在之后進行的一項針對香港居民的研究中，懷特也發現了同樣的結果。 紐約時報中英文網 http://www.zvkdrb.live
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，并不是每個人都能住在海邊。貝爾（Simon Bell）是愛沙尼亞生命科學大學（Estonian University of Life Science）的景觀建筑學首席教授以及愛丁堡大學（University of Edinburgh）開放空間中心（OPENspace Centre）的副主任，他和他的同事正在調查在歐洲修復被遺棄的水體是否有幫助。他們在修復前后采訪當地的居民。修復的水體包括愛沙尼亞首都塔林（Tallinn）外一個破舊的海灘、愛沙尼亞第二大城市塔爾圖（Tartu）一幢蘇式公寓大樓附近的工業運河，以及西班牙、葡萄牙、瑞典和英國的一些地方。
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.