BBC：城市和鄉(xiāng)村哪個更宜居？

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.

不管你是擔(dān)心污染還是壓力，你可能想知道，離開你的城鎮(zhèn)或城市去農(nóng)村，是否不僅能增進(jìn)你的幸福感，還能促進(jìn)你的健康。

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.

但是，能幫助我們找到最健康的生存環(huán)境的實(shí)證研究少得令人吃驚。當(dāng)科學(xué)家們開始梳理健康與環(huán)境之間的聯(lián)系時，他們發(fā)現(xiàn)，許多細(xì)微的差別既可以讓某一特定環(huán)境帶來的益處有所增加，也可以使其有所減損。無論是擁有數(shù)百萬人口的大都市，還是荒蕪的海灘，都是如此。

“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(xué)醫(yī)學(xué)院(University of Exeter Medical School)的環(huán)境心理學(xué)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(dǎo)什么，而是就自然環(huán)境如何影響健康和幸福這個問題，在尋找正反面的證據(jù);人類對環(huán)境的態(tài)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.

懷特和其他研究人員發(fā)現(xiàn)，似乎有無數(shù)的因素決定著我們周圍的環(huán)境如何對我們產(chǎn)生影響。這包括一個人的背景和生活環(huán)境，在該環(huán)境中生活質(zhì)量、持續(xù)時間以及在其中進(jìn)行何種活動等等。

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(jù)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(yīng) (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.

自然空間有益于體育和社會活動，這兩項活動又會帶來相當(dāng)多的益處。

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.

長時間身處大自然中，能夠減輕壓力造成的身體不適。當(dāng)我們外出散步或只是坐在樹下時，我們的心率和血壓都會下降。我們還釋放出更多的天然“殺手細(xì)胞”(killer cells)：即在身體各處游走的淋巴細(xì)胞，可以隨時捕捉癌細(xì)胞和受病毒感染的細(xì)胞。

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(shè)，但他們?nèi)栽谠噲D確定這是為什么。“一個占主導(dǎo)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(xué)(Michigan State University)的健康地理學(xué)家皮爾森(Amber Pearson)說。“從進(jìn)化論的觀點(diǎn)來看，我們也認(rèn)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.

然而，這并不一定意味著城市居民都應(yīng)該搬到農(nóng)村去。

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.

城市居民往往患哮喘、過敏和抑郁的程度更高。但他們的肥胖程度、自殺風(fēng)險和事故死亡率都較低。他們在老年時生活更幸福，總體上壽命更長。

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.

盡管我們總是把城市與污染、犯罪和壓力聯(lián)系在一起，但生活在農(nóng)村地區(qū)也可能需要付出一定的代價。例如，攜帶疾病的昆蟲和蛛形綱動物會影響健康，讓緬因州(Maine)那種田園詩般的小屋生活沒那么浪漫。

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).

在其它案例中，農(nóng)村污染構(gòu)成重大威脅。在印度，2015年空氣污染造成了110萬印度人死亡——其中75%的受害者是農(nóng)村居民，而不是城市居民。這主要是因?yàn)檗r(nóng)村居民更容易吸入因焚燒農(nóng)田、樹木或牛糞(用于做飯燃料和取暖)而受到污染的空氣。

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).

印度尼西亞刀耕火種式的土地清理同樣會造成持續(xù)數(shù)月的有毒霧霾，有時會影響到鄰國，包括新加坡、馬來西亞和泰國。與此同時，南美和非洲南部火災(zāi)產(chǎn)生的煙塵污染已經(jīng)在整個南半球蔓延開來。(即便如此，南半球的空氣通常比北半球的空氣要干凈——僅僅是因?yàn)槟抢锏娜烁?。