污染致中國北方人均壽命低於南方
黃安偉 2013年07月09日
周一，美國一家權威科學期刊公布一項研究結果稱，近幾十年，中國南方人的平均壽命至少比北方人長5年，原因是北方廣泛使用煤炭，導致的污染對健康造成了毀滅性影響。
該研究結果刊於《美國國家科學院院刊》(The Proceedings of the National Academy of Sciences)上。一名美國學者、一名以色列學者及兩名中國學者進行了這項研究，根據是對於1981年到2001年中國官方收集的健康及污染數據的分析。
該研究結果為中國環境惡化的巨大代價提供了一種新的評估。在中國北方，環境惡化部分是由於使用燃煤取能所造成的致命性污染物排放。研究者預測，因為室外空氣污染，生活在淮河以北的5億中國人將失去25億年的預期壽命。
麻省理工學院(Massachusetts Institute of Technology)環境經濟學教授邁克爾·格林斯通(Michael Greenstone)是該研究的美國成員。他說，「研究突顯了一個事實，在發展中國家，提高今天的收入與保護公共健康及環境質量之間存在一個取捨。因之突顯的另一個事實是，公共健康的代價比我們想像的要大。」
格林斯通在電話採訪中說，該研究還有一項令人震驚的結果：各個年齡段的人群中都出現了更高的死亡率。
該研究是首個完全基於中國國內收集的數據來評測這種影響的研究。研究結果是基於對生活在淮河南北的人口群體的分析。淮河位於長江與黃河之間，並與這兩條河流走向相同。多年來，在淮河以北，中國政府一直堅持為鍋爐提供免費煤炭以供冬季供暖。該政策及北方隨處可見的用煤作為燃料的工廠，使得南北之間的燃煤污染物排放差距巨大。
華盛頓大學(University of Washington)公共健康學院院長霍華德·弗魯姆金(Howard Frumkin)稱，該研究的一個「亮點」是，研究基於中國的區別性煤炭政策所導致的「自然實驗」。他說，「該結果在生物學上是可信的，結果也與以前的研究一致。」
這些研究者發現，在南方的平均污染水平之上每增加每立方米100微克微粒物質，出生時的預期壽命就減少3年。格林斯通稱，對於其他污染物基線水平高的發展中國家，這一估計也大致適用。
「中國污染帶來沉重代價的證據已經堆積如山，現在又多了一條，」研究中國環境政策的加州大學洛杉磯分校(University of California, Los Angeles)法學教授亞歷克斯·L·王(Alex L. Wang)說。「其他研究已經顯示了顯著的短期危害，其形式包括患病、誤工，甚至是胎兒面臨的危險。這項研究表明，煤礦污染的長期危害可能比我們想像的還要糟。」
王說，新的研究可能「有助於推動更加嚴格的環保法規」——例如，先前中國領導人要求某些地區關閉燃煤鍋爐的命令可能會擴大範圍，可能還會提前關閉的期限。
中國官方20年來的健康統計數據和該研究的研究者們對這些數據的分析表明，中國北方壽命預期的5.5年縮減幾乎完全是因為心肺疾病或相關健康問題所造成的死亡率上升。
同樣來自官方記錄的污染數據表明，淮河以北的顆粒物濃度每立方米比南部高184微克，也就是高出55%。
近期的一些科學研究已經揭示出中國的戶外空氣污染給人類帶來的損失。今年春天，《2010年全球致病量研究》(2010 Global Burden of Disease Study)公布的新數據顯示出，這樣的污染在2010年導致了120萬人的過早死亡，接近全球過早死亡總人數的40%。
一些中國官員試圖壓制把過早死亡與污染相聯繫的報道。根據新聞報道，中國官員對2007年的一份名為《中國污染代價》(Cost of Pollution in China)的報告進行了刪減，該報告得出結論，在中國，每年有35萬到40萬人因戶外空氣污染而過早死亡。這項研究是世界銀行(World Bank)在中國國家環境保護總局的協助下完成的，後者是中國環境保護部的前身。
今年，許多中國人表達了對空氣污染水平飆升的憤怒和失望，特別是在北方，這裡在今年1月創下了顆粒物水平的紀錄。今年夏天的污染水平仍然居高不下，許多外國人和中上層有孩子的中國人都想要離開這個國家，不想繼續忍受健康的危險。
格林斯通說，他並沒有一個基礎，無法對現在的污染水平與研究所覆蓋的1981年到2001年期間進行比較。在那一時期，測量顆粒物的方法是不同的。格林斯通還說，對於那些並非一生都在北方的人，或是經常或長期去污染較少的地區旅行的北方居民，他不清楚中國北方的污染會對他們的預期壽命造成什麼樣的影響。
July 09, 2013
Pollution Leads to Drop in Life Span in Northern China, Research Finds
BEIJING — Southern Chinese on average have lived at least five years longer than their northern counterparts in recent decades because of the destructive health effects of pollution from the widespread use of coal in the north, according to a study released Monday by a prominent American science journal.
The study, which appears in The Proceedings of the National Academy of Sciences, was conducted by an American, an Israeli and two Chinese scholars and was based on analyses of health and pollution data collected by official Chinese sources from 1981 to 2001.
The results provide a new assessment of the enormous cost of China's environmental degradation, which in the north is partly a result of the emissions of deadly pollutants from coal-driven energy generation. The researchers project that the 500 million Chinese who live north of the Huai River will lose 2.5 billion years of life expectancy because of outdoor air pollution.
"It highlights that in developing countries there's a trade-off in increasing incomes today and protecting public health and environmental quality," said the American member of the research team, Michael Greenstone, a professor of environmental economics at the Massachusetts Institute of Technology. "And it highlights the fact that the public health costs are larger than we had thought."
Mr. Greenstone said in a telephone interview that another surprising result of the study was that the higher mortality rates were found across all age groups.
The study is the first measuring this kind of impact that relies purely on data collected within China. Its conclusions are based on analyses of population groups living in areas north and south of the Huai River. The Chinese government has for years maintained a policy of free coal for boilers to generate winter heating north of the river, which runs parallel to and between the Yellow and Yangtze Rivers. That policy and the ubiquity of northern coal-fired factories have contributed to the vast gap between the coal pollutants emitted in north and south.
Howard Frumkin, dean of the School of Public Health at the University of Washington, said a "strong point" of the study was its basis in the "natural experiment" resulting from China's disparate coal policies. "The results are biologically plausible, and consistent with previous research," he said.
For every additional 100 micrograms of particulate matter per cubic meter above the average pollution levels in the south, the life expectancy at birth drops by three years, the researchers found. Mr. Greenstone said that estimate could be roughly applied to other developing nations where the baseline level of pollutants was high.
"This adds to the growing mountain of evidence of the heavy cost of China's pollution," said Alex L. Wang, a law professor at the University of California, Los Angeles, who studies Chinese environmental policies. "Other studies have shown significant near-term harms, in the form of illness, lost work days and even risks to children beginning in utero. This study suggests that the long-term harms of coal pollution might be worse than we thought."
Mr. Wang said the new study could "help to build the case for more aggressive environmental regulation" — for example, a previous order by Chinese leaders to shut down coal-fired boilers in some areas could be widened, and faster shutdown times could be required.
The health statistics recorded through the two-decade period by Chinese officials and examined by the study's researchers showed that the 5.5-year drop in life expectancy in the north was almost entirely due to a rise in deaths attributed to cardiorespiratory diseases or related health problems.
The pollution data, also recorded by officials, indicated that the concentration of particulates north of the Huai was 184 micrograms per cubic meter higher than in the south, or 55 percent greater.
Several recent scientific studies have revealed the toll that China's outdoor air pollution is taking on humans. This spring, new data released from the 2010 Global Burden of Disease Study revealed that such pollution contributed to 1.2 million premature deaths in 2010, or nearly 40 percent of the global total.
Some Chinese officials have sought to quash reports that link premature deaths to pollution. According to news reports, Chinese officials excised parts of a 2007 report called "Cost of Pollution in China" that had concluded that 350,000 to 400,000 people die prematurely in China each year because of outdoor air pollution. The study was done by the World Bank with the help of the Chinese State Environmental Protection Administration, the precursor to the Ministry of Environmental Protection.
This year, many Chinese have expressed fury and frustration over the surging levels of air pollution, especially in the north, which in January had record levels of particulate matter. Pollution levels have remained high this summer, and many foreigners and middle- or upper-class Chinese with children are looking to leave the country rather than tolerate the health risks.
Mr. Greenstone said he did not have a basis for comparing pollution levels now with those during the period covered by the study, 1981 to 2001. During that time, the method of measuring particulate matter was different. Mr. Greenstone also said he did not know how pollution in northern China affected the life expectancy for people not living there for their entire lives, or for residents of northern China who made frequent or long trips to less polluted areas.
