好英语网美人均寿命延长归功空气污染减少
Continuing declines in air pollution are linked to increasing life expectancy, a national study has found.
美国一项全国性的研究发现，人均预期寿命的延长，跟空气污染持续减少有关。
From 2000 to 2007, air pollution, as measured in concentrations of particulate matter less than 2.5 micrometers in diameter, has continued to decrease, although not as rapidly as in the 1980s and '90s. But even the slower rate of decrease is apparently lengthening life expectancy.
从2000年到2007年，用直径小于2.5微米的颗粒物密度(PM 2.5)来测量的空气污染程度持续降低，尽管降低的速度没有20世纪八九十年代那样快。但是，即使空气污染程度降低的速度变慢，也显然延长了人均预期寿命。
The study, published online last week in the journal Epidemiology, used data from 545 counties nationwide, both metropolitan and rural, and found an average decrease of 1.56 micrograms per cubic meter in particulate pollution over the eight years. At the same time, life expectancy increased an average of 0.84 years.
这项研究于上周发表在《流行病学杂志》(Epidemiology)的网站上。根据来自全美545个县的都市及乡村的数据，在过去的八年里，每立方米内的颗粒污染物平均减少了1.56微克。同时，预期寿命平均增加了0.84年。
Of course, many other factors contribute to increased life span besides cleaner air. The researchers controlled for smoking prevalence, income and other health and economic factors. They estimated that about 18 percent of the increase in life span can be attributed to reduced air pollution.
当然，除了干净空气外，许多其他因素对延长寿命有所贡献。在排除了吸烟率、收入及其他健康和经济因素后，研究者判断，人均期望寿命延长约18%可归因于空气污染的减少。
"What this means is that even if particulate pollution has been declining in recent years at a slower rate, even if we have already done a lot of cleanup, still continuing to clean is important," said the senior author, Francesca Dominici , a professor of biostatistics at the Harvard School of Public Health. "Our paper is strong evidence that additional investment in cleaning the air is beneficial."
该报告资深作者、哈佛大学公共卫生学院生物统计学教授佛朗西斯卡·多米尼奇(Francesca Dominici)说，“这就意味着，尽管近几年颗粒物污染降低的速度放慢了，尽管我们已经做了许多空气治理工作，但继续减少空气污染还是很重要的。我们的报告有力地证明，对减少空气污染做额外投资是有益的。”