研究称空气污染可能损害语言和数学能力
香港——中国的一项大型研究表明，在空气污染和对人的语言和数学能力的负面影响之间存在着联系。
The link between pollution and respiratory diseases is well known, and most experts now believe that small particulates may also raise the risk for strokes and heart attacks. Whether this form of air pollution impairs cognition is not yet certain, but several studies have hinted at a connection.
污染和呼吸系统疾病之间的联系是众所周知的，此外大多数专家现在相信，微小颗粒还会增加中风和心脏病的风险。这种形式的空气污染是否会损害认知还不确定，但是几项研究显示可能存在这种联系。
The latest study, by researchers based in China and the United States, analyzed how long-term exposure to air pollution affected performance on nationwide math and word-recognition tests by more than 25,000 people across 162 Chinese counties. It was published on Monday in Proceedings of the National Academy of Sciences.
由在中国和美国的研究者进行的这项最新研究，分析了长期暴露在空气污染中对中国162个县超过25000人的全国数学和词汇识别测试成绩的影响。《美国国家科学院院刊》(Proceedings of the National Academy of Sciences)周一发表了这项研究。
The authors based their findings on models they built that combined weather and pollution data from specific locations in China where people had taken nationwide tests in 2010 and 2014, as well as the test scores themselves. Their analysis tried to document how short- and long-term pollution exposure might have affected the scores — and, by extension, the test-takers’ brains.
研究作者的发现基于他们所建的模型，这些模型结合了来自中国特定地点的气候和污染数据，受试者于2010年和2014年在这些地方接受了全国测试，模型还采用了这些测试的分数。他们的分析试图记录短期和长期暴露在空气污染中可能会如何影响这些分数——以及，可能如何进一步影响受试者的大脑。
The authors found that the cognitive impact of cumulative exposure among the test takers was especially pronounced among older men, and that the results were troubling in part because cognitive decline and impairment are risk factors for Alzheimer’s disease and other forms of dementia.
作者发现，累积的污染暴露对受试者认知的影响，在年长男性中最为明显，这些结果让人不安，部分是因为认知衰退和损伤是阿兹海默症和其他形式的失智症的风险因素。
The study “further amplifies the need to tackle air pollution now to protect the health of particularly the young and elderly populations,” Heather Adair-Rohani, a technical officer for public health and environment at the World Health Organization in Geneva, which was not involved in the study, said in an email.
这项研究“进一步强调，立即着手处理空气污染问题，对保护年幼和年长人口健康格外有必要”，日内瓦世界卫生组织公共卫生与环境技术官员希瑟·阿代尔-罗哈尼(Heather Adair-Rohani)在一封电子邮件中说，他没有参与这项研究。
Atmospheric pollution has long been recognized as a significant threat to global public health.
大气污染一直以来被认为是对全球公共健康的严重威胁。
In 2016, the W.H.O. reported that 92 percent of people worldwide breathe what it classified as unhealthy air. It defined that air as having concentrations of fine particulate matter, known as PM2.5, above 10 micrograms per cubic meter, or 35.3 cubic feet.
2016年，世界卫生组织报告称，全球92%的人呼吸着该组织认为不健康的空气。它对不健康的定义是空气中的微小颗粒——即PM2.5——浓度高于每立方米10微克。
The agency said in May that outdoor air pollution caused approximately 4.2 million premature deaths worldwide in 2016, more than a million of them in China, and that short- and long-term exposure increased the risk of stroke, heart disease, lung cancer and chronic and acute respiratory diseases.
该组织在5月表示，室外空气污染在2016年造成了大约420万例过早死亡，其中超过一百万发生在中国，短期和长期的污染暴露加剧了中风、心脏病、肺癌和慢性以及急性呼吸系统疾病的风险。
This month a study in the journal Environmental Science & Technology Letters calculated that air pollution was reducing average life expectancies; the exact risk depended on location — around nine months in Russia, for example, or 1.9 years in Egypt.
根据本月《环境科学与技术通讯》(Environmental Science & Technology Letters)一项研究的估算，空气污染正在减少平均预期寿命;具体的风险取决于地理位置——例如，在俄罗斯约为9个月，在埃及约为1.9年。
But few epidemiological studies have analyzed associations between air pollution and cognition in older adults, a team of researchers from France and Britain wrote in a 2014 study in the journal Epidemiology. Their study found that traffic-related pollution in greater London was associated with declining cognitive functions over time among study participants, who had an average age of 66.
但是，法国和英国的一组研究人员2014年在《流行病学》(Epidemiology)期刊上写道，很少有流行病学研究分析空气污染与老年人认知之间的联系。他们的研究发现，在大伦敦地区，交通相关污染与受试者认知机能随时间推移而下降相关，研究参与者平均年龄为66岁。
In China, which already has the world’s largest population of people with dementia, the number is expected to rise to 75.6 million by 2030, up from about 44.4 million in 2013, according to a report that year by Alzheimer’s Disease International, a nonprofit based in Chicago.
根据位于芝加哥的非营利组织阿尔茨海默病国际组织(Alzheimer's Disease International)今年的一份报告显示，中国拥有世界上最多的失智症患者，预计到2030年，将从2013年的4440万人增加到7560万人。
The new study’s findings “imply that the indirect effect on social welfare could be much larger than previously thought,” the authors wrote. “A narrow focus on the negative effect on health may underestimate the total cost of air pollution.”
这项新研究的结果“意味着对社会福利的间接影响可能比以前认为的要大得多，”作者写道。“对健康的负面影响关注过于狭隘，可能会低估空气污染的总成本。”
The study used test scores from the 2010 and 2014 editions of China Family Panel Studies, an interview-based exam given nationwide, as well as air-quality data from readings of three types of pollutants: sulfur dioxide, nitrogen dioxide and particulate matter that is between 2.5 and 10 micrometers in diameter, called PM10.
该研究使用了2010年和2014年中国家庭追踪调查(China Family Panel Studies)的测试结果，这是一项全国范围内的研究，包括基于面试的考试结果，以及三种污染物的空气质量数据：二氧化硫、二氧化氮和直径在2.5到10微米之间，被称为PM10的颗粒物质。
“Essentially, we compare the same person in two time periods,” said Zhang Xin, the study’s lead author and a pollution expert at Bejing Normal University, referring to the study’s methodology. “The major variation stems from exposure to local air pollution at the date of interview, which is largely random.”
“基本上，我们在两个不同时期比较同一个人，”该研究的主要作者、北京师范大学污染专家张欣提到该研究所采取的方法。“主要变量源于采访当天的当地空气污染，在很大程度上是随机的。”
The study found that “accumulative exposure” had a pronounced impact on verbal test scores — especially for older, less-educated men — and that cutting the local concentration of PM10 to levels that meet United States Environmental Protection Agency air quality standards would move people up from the median, or 50th percentile, to the 58th percentile on math test scores and the 63rd percentile on verbal scores.
该研究发现，“累积暴露”对口头测试结果有显著影响——特别是对于年龄较大、受教育程度较低的男性——并且，如果当地PM10的浓度降低到符合美国环境保护局(United States Environmental Protection Agency)空气质量标准的水平，会使人们的数学考试成绩从中位值，或第50个百分位，上升到第58个百分位;并令口头考试成绩上升到第63个百分位。
He Guojun, an economist at the Hong Kong University of Science and Technology who studies pollution in China, said that he hoped the new study would be the first of many to examine apparent links between pollution and cognition in China. “The paper is quite solid, both in terms of data and methodology and results,” said Dr. He, who was not involved in the study.
研究中国污染问题的香港科技大学经济学家何国俊表示，他希望这项新研究能够带动对中国污染与认知之间明显联系的更多研究。“在数据、方法和结果方面，这篇论文很扎实，”没有参与这项研究的何国俊说。
The research tried to minimize the impact of other variables besides pollution. For example, it excluded test takers who migrated across counties between 2010 and 2014, and others who worked in mining, smelting, wood processing and other “polluted occupations.”
该研究试图将污染以外的其他变量的影响降至最低。例如，它排除了2010年至2014年间跨县迁徙的测试者，以及从事采矿、冶炼、木材加工和其他“污染职业”的人。
However, Dr. He said, measuring long-term effects of pollution exposure can be difficult, in part because individual exposure depends on so many factors — including, for example, whether a person uses air filters at home.
然而，何国俊说，测试污染暴露的长期影响可能很困难，部分原因是个人暴露取决于很多因素，例如是否在家中使用空气过滤器。
In another critique, Rajasekhar Balasubramanian, an air quality expert at the National University of Singapore, noted that while the study’s authors speculate that continued exposure to pollution can alter brain chemistry, they offered no clinical proof. (The authors agreed, writing that the hypothesis should be explored further.)
在另一项批评中，新加坡国立大学的空气质量专家拉贾塞卡·巴拉苏布拉马尼安(Rajasekhar Balasubramanian)指出，虽然该研究的作者推测，持续暴露于污染之下会改变大脑化学物质，但他们没有提供临床证据。(论文作者表示同意，并写道应该进一步探讨该假设。)
But Dr. Balasubramanian said the study was useful in part because, while the effects of pollution on children’s cognition had been documented by epidemiologists, this was the first to focus on such risks to China’s older people. He said similar research was now needed in other countries. 但巴拉苏布拉马尼安表示，这项研究之所以有用，是因为虽然流行病学家已经记录了污染对儿童认知的影响，但这是第一次关注污染对中国老年人的风险。他说其他国家现在需要进行类似的研究。
“The outcome of such studies would provide a sound scientific basis for tightening air quality standards to curtail air pollution and protect public health in both developing and developed countries,” Dr. Balasubramanian, who was not involved in the study, said in an emailed statement.
“这类研究的结果将为提高空气质量标准提供合理的科学依据，以减少发展中国家和发达国家的空气污染，并保护公众健康，”未参与该研究的巴拉苏布拉马尼安在一份电子邮件声明中表示 。
As public outrage has grown in China over smog and respiratory illnesses related to it, officials have in recent years closed hundreds of coal-fired power plants, imposed limits on driving and residential coal burning, and sent teams of police officers to inspect factories.
由于中国公众对雾霾和与之相关的呼吸系统疾病的愤怒日益增加，近年来，官员关闭了数百座燃煤电厂，限制了车辆和住宅燃煤，并派出大批警察到工厂进行检查。
But China’s carbon dioxide emissions increased last year, and even though the country is on its way to meeting its major climate change goals, many of its cities still have dangerously high levels of outdoor air pollution.
但去年中国的二氧化碳排放量有所增加，尽管该国正在实现其主要的气候变化目标，许多城市仍然存在危险的重度户外空气污染。
In one sign of the problems, a study published in April found that about 142 million people, or just over half the population surveyed in 155 Chinese cities, were exposed in 2014 to average annual “multicontaminant concentrations” that were above the World Health Organization’s limits. The study said that eastern China and megacities were worst affected.
4月发表的一项研究揭示了这类问题的其中一个表现，研究发现，2014年大约有1.42亿人，或155个接受调查的中国城市的一半以上人口，暴露在高于世界卫生组织规定年平均浓度的多污染物中。该研究称，中国东部和特大城市受影响最严重。
