43.空气污染与痴呆症

Passage Forty-Three

Air pollution and dementia

空气污染与痴呆症

【1】Air pollution from traffic is linked to some of the more severe(serious) forms of dementia, and could be a significant(important) cause of the condition among those who are not already genetically predisposed to it, research suggests.

研究表明，交通造成的空气污染与一些较为严重的痴呆症有关，并且可能是那些没有遗传易感性的人患上痴呆症的一个重要原因。

【2】A study carried out in Atlanta, Georgia, found that people with higher exposure to traffic-related fine particulate matter air pollution were more likely to have high amounts of the amyloid plaques in their brains that are associated with Alzheimer's disease.

于乔治亚州亚特兰大进行的一项研究发现，在与交通相关的细颗粒物空气污染中暴露程度越高的人，大脑中淀粉样斑块的含量越高，而淀粉样斑块与阿尔茨海默病有关。

【3】The findings, which will alarm anyone living in a town or city, but particularly those living close to busy roads, add to the host of harms already known to be caused by road traffic pollution, ranging(changing) from climate change to respiratory diseases(illness).

这一发现将给所有住在城镇的人，尤其是那些住在繁忙道路附近的人敲响警钟。同时也增加了道路交通污染造成的许多已知危害，包括气候变化和呼吸系统疾病等。

【4】A team of researchers from Atlanta's Emory University set out to investigate(research) the effects on people's brains of exposure the type of fine particulate matter known as PM2.5.

来自亚特兰大埃默里大学的一组研究人员开始研究暴露在一种被称为PM2.5的细颗粒物中对人们大脑的影响。

【5】This consists of particles of less than 2.5 microns diameter - about a hundredth the thickness of a human hair - suspended in the air, and known to penetrate deep into living tissue, including crossing the blood-brain barrier. Traffic-related PM2.5 concentrations are a major source of the ambient(surrounding) pollution in the metro-Atlanta area, and also in urban centres across the planet.

PM2.5由直径小于2.5微米的颗粒组成，大约是人类头发粗细的百分之一，悬浮在空气中。 据我们所知，这种颗粒可以渗透到活体组织深处，甚至穿过血脑屏障。交通产生的PM2.5是亚特兰大市区和全球城市中心周围环境污染的主要来源。

【6】The Emory researchers examined(inspected) the brain tissue of 224 people from Atlanta, 90% of whom had a diagnosis of some form of dementia, who had agreed to donate their brains to medical science after their deaths.

埃默里大学的研究人员检查了来自亚特兰大的224人的脑组织，其中90%的人被诊断患有某种形式的痴呆症，他们同意在死后将自己的大脑捐献用于医学研究。

【7】They also investigated the traffic-related PM2.5 pollution exposure at subjects 'home addresses in the years leading up to their deaths. The average level of exposure in the year before death was 1.32 micro-grams per cubic metre, and 1.35 micrograms per cubic metre in the three years before death.

研究人员还调查了捐赠者死亡前几年的家庭住址，以及与交通有关的PM2.5污染暴露情况。捐赠者死亡前一年的平均暴露水平为每立方米1.32微克，死亡前三年的平均暴露水平为每立方米1.35微克。

【8】“We found that donors who lived in areas with high concentrations of traffic-related air pollution exposure, in particular(especial) PM2.5 exposure, had higher levels of Alzheimer's disease neuropathology in their brain”said Anke Huels, an assistant professor at Emory, who was the lead author on the study.

埃默里大学助理教授安克·霍尔斯是这项研究的主要作者，他说：“我们发现，居住在交通污染浓度高、尤其是PM2.5暴露水平高的地区的捐赠者，他们的大脑中的阿尔茨海默病神经病理水平更高。 

【9】“In particular, we looked at ... a score that is used to evaluate(assess) amyloid plaques in the brain in autopsy samples, and we showed that donors who live in areas with higher levels of air pollution also had higher levels of amyloid plaques in their brain.” There was a positive relationship between the exposure to high levels of PM2.5 and the levels of amyloid plaques in the brains.

具体而言，我们观察了一种用于评估尸检样本大脑中淀粉样斑块的评分，我们发现，生活在空气污染程度较高地区的捐赠者大脑中淀粉状斑块的水平也较高。”环境中PM2.5浓度与大脑中淀粉质斑块的水平之间存在正相关。

【10】Researchers found that people whose PM2.5 exposure was 1 micro-gram per cubic metre higher in the year before death were nearly twice as likely to have higher levels of amyloid plaques in their brains, while those with higher exposure in the three years before death were 87% more likely to have higher levels of plaques.

研究人员发现，去世前一年每立方米PM2.5浓度高出1微克的人，其大脑中淀粉样斑块的含量较高的可能性几乎是普通人的两倍，而去世前三年PM2.5浓度较高的人，其大脑中淀粉样斑块的含量较高的可能性要高出87%。

【11】Huels and her team also investigated whether having the main gene variant associated with Alzheimer's disease, APOEe4, had any effect on the relationship between air pollution and signs of Alzheimer's in the brain. We found the association between air pollution and the severity(seriousness) of Alzheimer's disease was stronger among those who did not carry an APOEe4 allele [gene variant], that is those who did not have that strong genetic risk for Alzheimer's, Huels said.

霍尔斯及其团队还调查了与阿尔茨海默病相关的主要基因变异APOEe4是否对空气污染和大脑中阿尔茨海默病的迹象之间的关系有任何影响。 霍尔斯说，“我们发现，空气污染与阿尔茨海默病严重程度之间的因果关系在那些没有携带APOEe4等位基因(基因变异)的人身上更为明显，也就是那些没有那么强的遗传风险患阿尔茨海默病的人身上。

【12】“Which suggests that environmental exposure to air pollution may explain some of the Alzheimer's risk in people whose risk cannot be explained by genetic factors.” The findings are published in the 21February online issue of Neurology, the medical journal of the American Academy of Neurology.

“这表明，暴露在空气污染的环境中可能解释了一些无法用遗传因素解释的阿尔茨海默氏症患病风险。”研究结果发表在2月21日的《神经病学》在线版上，这是美国神经病学学会的医学杂志。