研究：住临街房可能患痴呆

痴呆症常见的危险因素包括年龄、家族史和遗传病史。但最新研究指出，除此之外，还有另外一个因素可能会影响患痴呆症的可能性：居住在车水马龙的主干道旁边。加拿大一项新研究发现，由于空气中的污染物可能通过血液进入大脑，引发神经系统病变，住在交通繁忙地段附近的人患痴呆症的风险更高。

Living near a main road increases the risk of dementia, the first major research into air pollution and disease has shown.

首项研究空气污染与疾病关系的重要调查发现，住在主干道旁边有可能增加患痴呆的风险。

A decade-long study of 6.6 million people, published in The Lancet, found that one in 10 dementia deaths in people living within 50 metres of a busy road was attributable to fumes and noise.

该研究时长超过十年，参与样本超过660万人并发表在医学期刊《柳叶刀》上面。研究结果表明，在居住在嘈杂路段50米范围内的痴呆症死亡患者中，有十分之一的患者病因可归因为尾气和噪音。

There was a linear decline in deaths the further people lived away from heavy traffic.

结果表明，离车水马龙的道路越远，他们的死亡率越低，且呈直线下降。

Air pollution is already known to contribute to the deaths of around 40,000 people in Britain each year by exacerbating respiratory and heart conditions, while previous research showed emissions can cause brain shrinkage.

我们已经知道空气污染可引起呼吸系统及心脏健康的恶化，每年造成近乎4万英国人死亡。此前的研究还表明，尾气排放会引起大脑萎缩。

But the new study by Canadian public health scientists is the first to find a link between living close to heavy traffic and the onset of dementia, a discovery described as "plausible" and "impressive" by British experts.

然而，加拿大公共健康方面的科学家们最新的研究，却第一次找到住在马路旁和患痴呆几率上升之间的关系。这次发现被英国科学家们称之为“可信的”及“令人震惊的”。

Dr Hong Chen, the lead author from Public Health Ontario, said:

本次研究结果的首席作者、加拿大安大略省公共医疗局陈宏 "Our study suggests that busy roads could be a source of environmental stressors that could give rise to the onset of dementia."

“我们的研究结果表明繁忙的交通有可能成为一种加大患痴呆几率的环境压力源。”

"Increasing population growth and urbanisation has placed many people close to heavy traffic, and with widespread exposure to traffic and growing rates of dementia, even a modest effect from near-road exposure could pose a large public health burden."

“人口增长及城市化让许多人住在繁忙路段附近，大范围接触到繁忙交通，老年痴呆病患上升。住在路边的一般影响也有可能严重危及公共健康。”

"More research to understand this link is needed, particularly into the effects of different aspects of traffic, such as air pollutants and noise. Around 850,000 people suffer from dementia in Britain, and it is now the leading cause of death for both men and women."

“我们需要做更多研究证明这样的联系，特别是对交通各种不同方面的影响，比方说空气污染物及噪声。在英国，约85万人身患痴呆。痴呆现在已经是人们死亡的主要原因之一了。”

There has been concern that air pollution could be driving neurodegenerative conditions for many years.

有担心者表示，空气污染很有可能导致多年的神经退化。

Last year British scientists discovered tiny magnetic particles produced by car engines and brakes in the brains of people diagnosed with Alzheimer's disease.

去年，英国科学家在阿尔兹海默症患者的脑部发现了汽车发动机和刹车系统排放出的磁粒子。

In the new study, the team tracked all adults aged between 20 and 85 living in Ontario for more than a decade from 2001 to 2012. They used postcodes to determine how close people lived to a main road and analysed medical records to see if they went on to develop dementia, Parkinson's disease or multiple sclerosis.

最新的这次研究从2001年到2012年跨越10年，研究人员追踪了住在安大略省的人们，年龄跨度涵盖20岁到85岁。他们用邮编来确认大家住得离主干道有多近，并进一步分析他们的医疗记录，分析他们会不会得老年痴呆、帕金森或者是多发性硬化。

Over the study period, more than 243,000 people developed dementia, 31,500 people developed Parkinson's disease and 9,250 people developed multiple sclerosis.

在研究过程中，超过24.3万人患上了老年痴呆，约3.15万人患上了帕金森，而有9250人得了多发性硬化。

While there was no association between living near a road and Parkinson's disease or multiple sclerosis, dementia risk reduced as people lived further from a main road, with a 7 percent higher risk in developing dementia among those living within 50 metres; a 4 percent higher risk at 50-100 metres and a 2 percent higher risk at 101-200 metres.

目前还没有找到住得离繁忙路段远近和患帕金森或多发性硬化几率的联系，然而人们住得离主干道越远，患老年痴呆的几率就会下降。这些住所离主干道50米之内的人患痴呆的几率会高7%，50-100米内，几率会高4%，而距离在101-200米内几率会高2%。

After 200 metres there was no increase.

距离超过两百米后，就几乎没有什么显著的影响了。

Researchers believe that noise of traffic may also play a role in the raised risk as well as other urban pollution, which is often present near busy roads.

研究者相信交通噪音及其他城市污染也很有可能是导致风险增加的原因。这在嘈杂路段非常常见。