北京——周四发表的一项研究显示,科学家们发现了造成中国臭名昭著的冬季雾霾的一个新元凶,控制它可以维持北京和其他东北城市去年冬天在空气质量方面所经历的显著进步。
Scientists from Harvard and two Chinese universities reported that emissions of formaldehyde — principally from vehicles and chemical and oil refineries — played a larger role than previously understood in producing the thick, toxic pollution that chokes much of the country each winter.
来自哈佛和两所中国大学的科学家报告称,甲醛的释放——主要来自汽车、化工和炼油厂——在产生厚重且有毒的污染中发挥的作用,比人们从前的认知更大。每个冬天,污染让这个国家的大部分地区令人窒息。
In a report published in the journal Geophysical Research Letters, the scientists argued that “a large portion” of the sulfur in the haze was the result of a chemical reaction between formaldehyde and sulfur dioxide released by burning coal.
在一份发表在《地球物理研究通讯》(Geophysical Research Letters)上的报告中,科学家们认为,雾霾中“很大一部分”的硫都是燃煤释放的甲醛和二氧化硫的化学作用下的产物。
China’s efforts to reduce the haze have focused lately on reducing sulfur dioxide emissions. While those efforts have shown some success, with drastic declines in pollutants recorded last winter, the research suggests that China could improve air quality still more by directing efforts — and resources — toward reducing emissions of formaldehyde in vehicles and industrial refining.
中国减少雾霾的努力最近集中在降低二氧化硫的排放量上。尽管这些努力已经展示了一些成效,去年冬天,污染记录大幅下降,但研究表明,要提升空气质量,中国可以通过更为直接的努力——和智谋——进一步减少车辆和工业精炼释放的甲醛。
“Our research points toward ways that can more quickly clean up air pollution,” said Jonathan M. Moch, a Harvard researcher and lead author of the study.
“我们的研究是针对可以更快清洁空气污染的方法,”哈佛研究员、该研究的第一作者乔纳森·M·莫赫(Jonathan M. Moch)说。
The easiest fixes include improving ignition switches on cars and trucks and fitting nozzles at gas stations with rubber seals to prevent fumes from escaping, he said. Reducing emissions from chemical and oil refineries, which are heavily concentrated in Tianjin, a coastal metropolis near Beijing, could also have a disproportionate impact, he said, but could prove more difficult to enforce.
他指出,最容易的修复措施包括改进小汽车和卡车的点火开关,在加油站安装带有橡胶密封圈的喷嘴,防止气体泄漏。减少集中在天津这个靠近北京的沿海城市的化工和炼油厂的废气排放,也会产生极大的影响,他说,但执行起来可能会更加困难。
As with efforts to curb the industrial burning of coal, significant cuts in the output of refineries could clash with the government’s economic and political imperatives, particularly at a time when the trade war with the United States has threatened China’s growth.
与抑制工业燃煤的努力一样,精炼工厂产量的大幅削减可能与政府的经济和政治需要发生冲突,尤其是在中美贸易战威胁到中国经济增长之际。
When the Chinese Ministry of Ecology and Environment issued its annual guidelines for 28 cities in the northeast last month, it eased requirements for new cuts in emissions somewhat and lifted restrictions imposed last winter that forced many steel mills, coking plants and other factories to shut down for several months. That has led to worries that the coming winter could once again see choking haze many times the safe levels recommended by the World Health Organization.
中国生态环境部上个月发布了针对东北28个城市的年度督导计划,该计划在一定程度上放宽了新的减排要求,并取消了去年冬天实施的一些迫使许多钢铁厂、炼焦厂和其他工厂关闭了几个月的限制措施。这让人们担心,在即将到来的冬天可能会再次看到令人窒息的、浓度是世界卫生组织(WHO)建议的安全水平数倍的雾霾。
The country’s pollution — measured by the concentration of PM 2.5, or particulate matter of a size deemed especially harmful — has been blamed for as many as one million premature deaths a year.
这个国家的污染——由PM2.5这种被认为特别有害的颗粒物的浓度所测量——被认为是导致每年一百万人过早死亡的罪魁祸首。
The main particulate matter in pollution in China has long been thought to be sulfate, a product of sulfur dioxide released by burning coal. But another sulfur molecule, hydroxymethane sulfonate, is also a significant contributor, according to the study, conducted with scientists from Tsinghua University in Beijing and the Harbin Institute of Technology in Harbin, the capital of China’s northernmost province, Heilongjiang.
长期以来,人们一直认为中国污染的主要颗粒物是硫酸盐,一种燃煤释放的二氧化硫的产物。但一项由北京清华大学和位于中国最北部省份黑龙江省首府哈尔滨的哈尔滨工业大学的科学家进行的研究表明,另一种硫分子,羟基甲烷磺酸盐,也是一个重要来源。
The molecule is formed by a chemical reaction between formaldehyde and sulfur dioxide, and explains why “extreme air pollution events” have persisted despite the efforts to cut sulfur emissions, the researchers found.
研究人员发现,这种分子是由甲醛和二氧化硫之间的化学反应形成的,这也解释了为什么尽管努力减少二氧化硫的排放,“极端空气污染事件”仍然持续存在。