空气污染可导致精神分裂或自闭症

1、空气污染可导致精神分裂或自闭症Mice study links air pollution to autism, schizophreniaA new research describes how the brains of mice are damaged by exposure to air pollution in early life.The brain damage includes the enlargement of a part of the brain that is seen in humans who have autismandschizophrenia.The stu

2、dy is published in the journal Environmental Health Perspectives.As in autism and schizophrenia, the changes occurred predominately in males. The mice also performed poorly in tests of short-term memory, learning ability, and impulsivity.The new findings are consistent with several recent studies th

3、at have shown a link between air pollution and autism in children.Most notably, a 2013 study in JAMA Psychiatry reported that children who lived in areas with high levels of traffic-related air pollution during their first year of life were three times as likely to develop autism.“ Our findings add

4、to the growing body of evidence that air pollution may play a rolein autism, as well as in other neuro developmental disorders, ” said Deborah Cory-Slechta, Ph.D., professor of environmental medicine at the University of Rochester and lead author of the study.In three sets of experiments, Cory-Slech

5、ta and her colleagues exposed mice to levels of air pollution typically found in mid-sized US cities during rush hour.The exposures were conducted during the first two weeks after birth, a critical time in the brain s development.micThe were exposed to polluted air for four hours each day for two fo

6、ur-day periods.In one group of mice, the brains were examined 24 hours after the final pollution exposure. In all of those mice, inflammation was rampant throughout the brain, and the lateral ventricles chambers on each side of the brain thatcontain cerebrospinal fluid were enlarged two to three tim

7、es their normal size.“ When we looked closely at the ventricles, we could see that the white matter thatnormally surrounds them hadn t fully developed,-Slecht”said. Cory“ It appears thatinflammation had damaged those brain cells and prevented that regionof the brain from developing, and the ventricl

8、es simply expanded to fill the space.The problems were also observed in a second group of mice 40 days after exposure and in another group 270 days after exposure, indicating that the damage to the brain was permanent.Brains of mice in all three groups also had elevated levels of glutamate, a neurot

9、ransmitter, which is also seen in humans with autism and schizophrenia. Most air pollution is made up mainly of carbon particles that are produced when fuel is burned by power plants, factories, and cars. For decades, research on the health effects of air pollution has focused on the part of the bod

10、y where its effects are most obvious the lungs.That research began to show that different-sized particles produce different effects. Larger particles, the ones regulated by the Environmental Protection Agency (EPA), are actually the least harmful because they are coughed up and expelled.But many res

11、earchers believe that smaller particles known as ultrafine particles which are not regulated by the EPAare more dangerous, because they are small enough to travel deep into the lungs and be absorbed into the bloodstream, where they can produce toxic effects throughout the body.That assumption led Co

12、ry-Slechta to design a set of experiments that would show whether ultrafine particles have a damaging effect on the brain, and if so, to reveal the mechanism by which they inflict harm. The study is the first scientific work to do both.“ I think these findings are going to raise new questions about

13、wherththe currentregulatory standards for air quality are sufficient to protect our children,” saCory-Slechta.相关内容一项新研究表明，老鼠若在幼年期长期接触污染大气，脑部可能会受损。这种受损包括大脑某一部分变肿大， 就人类而言，变肿大的部分常出现在自闭者与精神分裂患者脑中。相关研究结果已发布在环境健康透视杂志上。就自闭症和精神分裂而言， 这种变化更多出现在雄性之中。 此外，试验中雄性小鼠的短期记忆、学习能力和冲动性行为均有下降。除本实验外，其他最近几项研究也表明大气污染可导致儿童自闭症

14、。最显著的是 2013 年美国医学协会杂志 : 精神病学分册上发表的一项研究，该研究显示儿童若在一岁多时生活在交通尾气污染严重地区， 患上自闭症的概率是同龄儿童的三倍。“随着调查的深入，我们搜集到的证据也越来越多，这些数据一致表明大气污染和自闭症之间存在必然联系，污染甚至还可能引发神经系统发育障碍， ”罗切斯特大学环境医学教授德博拉 ?科里 ?斯彻塔解释道。在三组试验中， 斯彻塔与同事采集了美国二线城市交通高峰期的空气样本， 并将老鼠置于其中。科里 ?斯彻塔用出生仅两周的老鼠进行试验，此时正值其脑部发育的关键时期。试验期间，小鼠每天要呼吸污染的空气长达四个小时， 为期两到四天， 试验分为两期进

15、行。试验结束后，科里为第一组小鼠进行了长达二十四小时的脑部检查。 所有小鼠的大脑和侧脑室均已严重发炎 左右脑的脑腔里都是脑脊髓液 小鼠的大脑增大两至三倍。“我们仔细检查了小鼠的脑室，发现大脑的白质未完全发育 ”，科里 ?斯彻塔说道。“我们观察发现炎症损害了小鼠的脑细胞，限制了大脑的发育，脑室不断扩张，占满了整个大脑。 ”科里 ?斯彻塔还在试验后 40 天和 270 天分别测试了第二和第三组小鼠， 发现大气污染对脑部造成的伤害是永久性的。三组小鼠的脑内的谷氨酸水平也明显升高， 谷氨酸是一种神经递质， 如果人类脑部的谷氨酸水平过高，则会患上自闭症和精神分裂。空气污染产生的主要原因是发电厂， 工厂和汽车燃烧燃料后排放出的碳粒子。 几十年来，在研究大气污染对健康的影响时，人们往往只关注病症最明显的部位 肺。随着研究的深入， 研究人员渐渐发现不同大小的碳颗粒对大脑的损害不同。 大型碳颗粒受美国环保局监管，其