中國霧霾新元兇：甲醛

BEIJING — Scientists have found a new culprit contributing to China’s notorious wintertime smog, and controlling it could help sustain the significant improvements in air quality that Beijing and other northeastern cities experienced last winter, according to research published on Thursday.

北京——周四發(fā)表的一項研究顯示，科學(xué)家們發(fā)現(xiàn)了造成中國臭名昭著的冬季霧霾的一個新元兇，控制它可以維持北京和其他東北城市去年冬天在空氣質(zhì)量方面所經(jīng)歷的顯著進步。

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.

來自哈佛和兩所中國大學(xué)的科學(xué)家報告稱，甲醛的釋放——主要來自汽車、化工和煉油廠——在產(chǎn)生厚重且有毒的污染中發(fā)揮的作用，比人們從前的認(rèn)知更大。每個冬天，污染讓這個國家的大部分地區(qū)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.

在一份發(fā)表在《地球物理研究通訊》(Geophysical Research Letters)上的報告中，科學(xué)家們認(rèn)為，霧霾中“很大一部分”的硫都是燃煤釋放的甲醛和二氧化硫的化學(xué)作用下的產(chǎn)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.

中國減少霧霾的努力最近集中在降低二氧化硫的排放量上。盡管這些努力已經(jīng)展示了一些成效，去年冬天，污染記錄大幅下降，但研究表明，要提升空氣質(zhì)量，中國可以通過更為直接的努力——和智謀——進一步減少車輛和工業(yè)精煉釋放的甲醛。

“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.

“我們的研究是針對可以更快清潔空氣污染的方法，”哈佛研究員、該研究的第一作者喬納森·M·莫赫(Jonathan M. Moch)說。

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，最容易的修復(fù)措施包括改進小汽車和卡車的點火開關(guān)，在加油站安裝帶有橡膠密封圈的噴嘴，防止氣體泄漏。減少集中在天津這個靠近北京的沿海城市的化工和煉油廠的廢氣排放，也會產(chǎn)生極大的影響，他說，但執(zhí)行起來可能會更加困難。

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.

與抑制工業(yè)燃煤的努力一樣，精煉工廠產(chǎn)量的大幅削減可能與政府的經(jīng)濟和政治需要發(fā)生沖突，尤其是在中美貿(mào)易戰(zhàn)威脅到中國經(jīng)濟增長之際。

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.

中國生態(tài)環(huán)境部上個月發(fā)布了針對東北28個城市的年度督導(dǎo)計劃，該計劃在一定程度上放寬了新的減排要求，并取消了去年冬天實施的一些迫使許多鋼鐵廠、煉焦廠和其他工廠關(guān)閉了幾個月的限制措施。這讓人們擔(dān)心，在即將到來的冬天可能會再次看到令人窒息的、濃度是世界衛(wèi)生組織(WHO)建議的安全水平數(shù)倍的霧霾。

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.

這個國家的污染——由PM2.5這種被認(rèn)為特別有害的顆粒物的濃度所測量——被認(rèn)為是導(dǎo)致每年一百萬人過早死亡的罪魁禍?zhǔn)住?/p>

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.

長期以來，人們一直認(rèn)為中國污染的主要顆粒物是硫酸鹽，一種燃煤釋放的二氧化硫的產(chǎn)物。但一項由北京清華大學(xué)和位于中國最北部省份黑龍江省首府哈爾濱的哈爾濱工業(yè)大學(xué)的科學(xué)家進行的研究表明，另一種硫分子，羥基甲烷磺酸鹽，也是一個重要來源。

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.

研究人員發(fā)現(xiàn)，這種分子是由甲醛和二氧化硫之間的化學(xué)反應(yīng)形成的，這也解釋了為什么盡管努力減少二氧化硫的排放，“極端空氣污染事件”仍然持續(xù)存在。