华北雾霾平均令人减寿5.5年,谁来买单

China’s air pollution has cut life expectancy by 5.5 years in the north of the country and caused higher rates of lung cancer, heart attacks and strokes, according to a groundbreaking study.

一项突破性研究显示，中国的空气污染已使中国北方居民的预期寿命减少5.5年，还提升了肺癌、心脏病和中风的发病率。

The worsening toxic smog in northern China became an issue of national concern after air pollution spiked to record levels in Beijing in January. Worried citizens have made runs on air filters and face masks, and “pollution domes” that provide filtered air for sports activities are increasingly common.

今年1月北京的空气污染程度飙升至创纪录水平后，中国北方不断恶化的有毒雾霾成为一个举国关切的问题。忧心忡忡的居民抢购空气过滤器和口罩，为体育活动提供过滤空气的“空气净化穹顶”也日益常见。

But the body of scientific research on the health impact is slim because there is little historical precedent for prolonged exposure to such high levels of air pollution.

但是，有关健康影响的科研文献迄今较少，因为历史上很少有这样持续暴露于高度空气污染的先例。

Using decades of pollution data from across China, the new study, co-authored by professors from Massachusetts Institute of Technology in the US, Tsinghua University and Peking University in Beijing, and the Hebrew University of Jerusalem, calculates that air pollution in the north caused the loss of 2.5bn years of human life expectancy during the 1990s.

新的研究利用中国各地数十年期间的污染数据，并由美国麻省理工学院(MIT)、北京的清华大学和北京大学，以及耶路撒冷希伯来大学(Hebrew University of Jerusalem)的多名教授联名发表报告。据这项研究估算，华北的空气污染已在上世纪90年代总共减少25亿年的人类预期寿命。

The findings show the health impact of air pollution is far higher than previously believed.

研究结果显示，空气污染的健康影响远高于此前的认识。

“This is the first time anyone has got the data to show how severe long-term pollution affects human health, both in terms of life expectancy and the types of disease,” said Li Hongbin, an economics professor at Tsinghua University and a co-author of the study.

“这是第一次有人拿出数据显示，长期污染多么严重地影响人体健康，无论是就预期寿命还是就疾病类型而言，”清华大学经济学教授、此项研究的联名作者之一李宏彬表示。

“It shows how high the cost of pollution is in terms of human life – and that it is worth it for the government to spend more money to solve the pollution issue, even if we have to sacrifice growth.”

“它显示出，就人类寿命而言，污染的代价有多高，这进而说明，政府加大投入、解决污染问题是值得的，即便我们必须牺牲一些增长。”

Mr Li estimates the shorter life expectancy identified by the study in northern China is equivalent to reducing the work force there by one-eighth.

李宏彬表示，这项研究发现的华北居民预期寿命缩短，相当于把当地劳动力人数削减八分之一。

China’s breakneck economic development during the past three decades has been accompanied by the widespread degradation of air, soil and water. Environmental worries are now a growing source of social unrest and public protest, particularly because of health concerns.

过去30年期间，中国经济突飞猛进的同时，也出现了空气、土壤和水源的大范围退化。环境担忧，尤其是健康关切，如今日趋成为社会不安定和公开抗议的来源。

In response, Beijing has tightened environmental laws and regulations but these efforts have so far had little impact in reversing decades of damage.

作为回应，北京方面收紧了环保法律法规，但这些努力在逆转数十年的损害方面迄今收效甚微。

The study, published on Monday in the US journal, Proceedings of the National Academy of Sciences, compares populations north and south of the Huai River, which runs through central China. North of the river, the government distributed free coal for heating in winter, resulting in higher rates of air pollution compared with areas to the south.

研究报告周一发表于《美国国家科学院院刊》(Proceedings of the National Academy of Sciences, PNAS)。这项研究比较了横贯中国中部的淮河南北的居民。在淮河以北，政府免费发放煤炭用于冬季取暖，造成这些地区与南方相比空气污染程度较高。

“What we found is that people who live just north of the river have life expectancy of five and a half years [less],” said Michael Greenstone, a professor of environmental economics at MIT and a co-author of the study.

“我们发现，生活在这条河北岸的人，预期寿命就少了5年半，”麻省理工学院环境经济学教授、此项研究的联名作者之一迈克尔•格林斯通(Michael Greenstone)表示。

“Part of the novelty of this study is that this was conducted with data on actual pollution measurements in China, and actual health and life expectancy in China. It is not an extrapolation,” he said.

“这项研究的部分新颖之处在于，它是根据中国实际污染测量数据，以及中国的实际健康和预期寿命数据进行的。没有使用外推法，”他表示。

Using pollution data from 1981-2000 and health data from 1991-2000, the study found that an increase of 100 micrograms of total particulate matter per cubic metre (a measure of air pollution), corresponded to a three-year reduction in average life expectancy.

使用1981年至2000年的污染数据和1991年至2000年的健康数据，这项研究发现，每立方米空气所含的总颗粒物（空气污染的一种衡量标准）增加100微克，就对应于平均预期寿命减少3年。

Most previous calculations of the health cost of Chinese pollution are extrapolated from research conducted in the US, where overall pollution levels are much lower.

此前，有关中国污染造成的健康代价的多数估算，都是根据美国进行的研究推算出来的，但美国的总体污染水平低得多。