來自中國霧霾之都的環境觀察
Back in 1970, Los Angeles was known as the smog capital of the world — a notorious example of industrialization largely unfettered by regard for health or the environment. Heavy pollution drove up respiratory and heart problems and shortened lives.
在1970年，洛杉磯曾被稱爲“世界光化學煙霧之都”，它是一個不太考慮健康和環境因素，大肆進行工業化建設的臭名昭著的例子。嚴重的污染加重了呼吸道和心臟疾病的問題，也縮短了人們的壽命。
But 1970 was also the year the environmental movement held the first Earth Day and when, 45 years ago this month, Congress passed a powerful update of the Clean Air Act. (Soon after, it was signed by President Richard Nixon, and it was followed by the formation of the Environmental Protection Agency and passage of the Clean Water Act, making him one of the most important, though underappreciated, environmentalists in American history.)
但也是在1970年，環保運動人士第一次舉行了“世界地球日”(Earth Day)。而且在45年前的9月，國會通過了頗具影響力的新《清潔空氣法》(Clean Air Act)。不久以後，理查德·尼克松(Richard Nixon)總統正式簽署了該法案，之後美國國家環境保護局（Environmental Protection Agency，簡稱EPA）成立，《清潔水法案》(Clean Water Act)也獲得通過。尼克松因此稱得上是美國曆史上最重要的環保人士之一，儘管他在這方面的成就沒有得到充分的認可。
Since that time, the Clean Air Act has repeatedly been challenged as costly and unnecessary. As a fight brews over President Obama’s new use of the law to address global warming, it’s worth re-examining the vast difference the law has already made in the quality of the air we breathe, and in the length of our lives.
從那個時候開始，《清潔空氣法》就反覆受到挑戰，它被認爲成本高且不必要。在奧巴馬總統和民主黨正醞釀重新利用這一法案解決全球變暖問題時，有必要來重新審視一下，這項法案給我們呼吸的空氣質量和預期壽命帶來了怎樣的巨大改變。
Numerous studies have found that the Clean Air Act has substantially improved air quality and averted tens of thousands of premature deaths from heart and respiratory disease. Here, I offer new estimates of the gains in life expectancy due to the improvement in air quality since 1970 — based on observations from the current “smog capital” of the world, China. (To learn more about how this was calculated, click here.)
有許多研究發現，《清潔空氣法》大幅提高了空氣質量，讓數以萬計的人免於因心臟和呼吸道疾病而提早死亡。在這裏，我對自1970年以來因空氣質量改善而實現的預期壽命增長，提供一些最新的估算數據，其中參照了對當今的世界“霧霾之都”中國的觀察（瞭解有關該估算方式的更多信息，請點擊這裏）。
For several decades starting in the 1950s, China’s government gave residents in the northern half of the country free coal for winter heating, effectively creating a natural experiment in the health impact of pollution. My colleagues and I recently compared pollution and mortality rates between the north south of China and calculated the toll of airborne particulate matter, widely believed to be the most harmful form of air pollution, on life expectancy.
從1950年代開始的幾十年裏，中國政府給華北地區的居民提供免費的煤塊用來冬天取暖，這實際上構成了一個觀察污染對健康的影響的天然實驗。我和同事最近比較了中國南北方污染和死亡率數據的差異，計算出懸浮顆粒物質導致的死亡人數。普遍認爲懸浮顆粒物是對人類壽命危害最大的空氣污染物。
Applying that formula to E.P.A. particulate data from 1970 to 2012 yields striking results for American cities.
將EPA統計的1970年到2012年間的顆粒物質數據，用同一公式計算，就得到了關於美國城市的驚人數據。
In Los Angeles, particulate pollution has declined by more than half since 1970. The average Angeleno lives about a year and eight months longer. Residents of New York and Chicago have gained about two years on average. With more than 42 million people currently living in these three metropolitan areas, the total gains in life expectancy add up quickly.
在洛杉磯，顆粒物質污染自1970年以來減少了超過一半。洛杉磯人的平均壽命延長了大約一年零八個。紐約和芝加哥的居民平均壽命延長了大約兩年。超過4200萬人目前居住在這三大都市圈，整體預期壽命的延長，積累起來頗爲可觀。
But some of the greatest improvements occurred in smaller towns and cities where heavy industries appeared to operate with few restrictions on pollution.
但狀況改善最明顯的其實是一些規模更小的城鎮，在那裏經營的重工業企業，以前似乎不會受到任何污染方面的監管。
In 1970, the Weirton, .–Steubenville, Ohio, metropolitan area had particulate concentrations similar to current-day Beijing. A child born there today can expect to live about five years longer than one born in 1970.
1970年，西弗吉尼亞州的韋爾頓(Weirton)和俄亥俄州的斯托本維爾(Steubenville)區域，存在懸浮顆粒濃度高的問題，與如今北京的狀態類似。現在出生在那裏的孩子，預計可以比1970年出生在那裏的孩子，多活大約五年。
More than 200 million people currently live in places monitored for particulates in 1970 and today. (The E.P.A. focuses on the most heavily populated or polluted areas of the country, which is why these calculations exclude approximately 115 million people.) On average, these people can expect to live an additional 1.6 years, for a total gain of more than 336 million life-years.
現在，有2億多人口生活在1970年和現在都有懸浮顆粒數據監測的地區（EPA主要關注美國人口密集或污染嚴重的地區，因此有大約1.15億人口不在計算範圍內）。平均而言，這2億人預計可以多活1.6年，這些人口增加的壽命長度總計超過3.36億年。
Not all of these benefits came from Clean Air Act regulations. Other factors include local regulations and the shifting of relatively dirty industries abroad. But the Clean Air Act was a primary cause.
實現這些改變不能僅僅歸功於《清潔空氣法》的實施。一些地方法規和一些污染相對嚴重的產業被轉移到國外等因素，也發揮了作用。但《清潔空氣法》的確是主要原因。
The history and impact of the Clean Air Act can serve as a valuable case study for countries that are struggling today with the extraordinary pollution that we once faced. In Northern China, where pollution is curtailing lives by an average of five years, the government has at last declared a “war on pollution.” While enforcement is not perfect, the government has improved transparency and amended environmental protection laws to impose stricter punishments against polluters.
《清潔空氣法》的歷史和影響，可以爲正在努力解決我們也曾面臨過的嚴重污染問題的那些國家，提供有價值的研究案例。在中國北部地區，環境污染現在讓人們的壽命平均縮短了五年，中國政府終於宣佈開啓“治理污染之戰”。儘管執行得並不完美，但中國政府已經提高了透明度，也修訂了環境保護法，對污染環境者採取更嚴厲的懲罰。
In India, pollution is abridging the average person’s life by about three years. But the growing outrage has not yet coalesced into forceful action, although it’s possible that pressure to take steps against climate change will also have an effect on improving air quality.
在印度，環境污染現在讓人們的平均壽命降低了大約三年。但民衆日益加劇的不滿，尚未促使政府採取有力行動。不過，採取措施應對氣候變化的壓力，可能也會對改善空氣質量產生影響。
The hundreds of millions of life-years saved from improved air quality in our country didn’t happen by accident or overnight. This happened because a collective voice for change brought about one of the most influential laws of the land.
在美國，因空氣質量提高而延長的總計數億年壽命，並非偶然實現，也不是一蹴而就，而是因爲民衆集體發聲，要求做出改變，才促成了這個國家最有影響力的法律之一。
As the United States and other nations continue to debate the costs of environmental regulation, they can do so with the knowledge that the benefits can be substantial. As proof, we need look no further than the five extra years residents of Weirton-Steubenville are living and the hundreds of millions of years gained by Americans throughout the nation.
在美國和其他國家繼續就環境法規的成本進行辯論時，他們需要了解，這麼做的益處是非常可觀的。只要看看韋爾頓-斯托本維爾區域的居民因環境改善而多出的五年壽命，以及全國民衆整體增加的數億年壽命，就足以明白這一點。
