导读:随着医疗和生活水平提高，人类平均寿命在持续增长，但美国人平均寿命出现二十年来首次下降。主要原因为疾病造成的死亡率上升。
Life expectancy in the United States has declined for the first time in more than two decades.
美国人的平均寿命二十年来首次出现下降。
Data from the National center for Health Statistics showed a drop for men from 76.5 years in 2014 to 76.3 in 2015, and from 81.3 to 81.2 for women.
国家卫生统计中心的数据表明，男性平均寿命从2014年的76.5岁降至2015年的76.3岁，而女性从81.3岁降至81.2岁。
The figures show rises in several causes of death, especially heart disease, dementia and accidental infant deaths.
数据显示，几种导致死亡的因素增大，尤其是心脏病、痴呆以及婴儿突发死亡。
Life expectancy last fell during the peak of the HIV/Aids crisis in 1993.
上一次平均寿命下降出现在1993年，在艾滋病/艾滋病毒危机顶峰时期。
It has improved slightly in most of the years since World War Two, rising from a little more than 68 years in 1950.
自二战后，比起1950年68岁的平均寿命，大多年份的平均寿命都有小幅度上升。
It also fell in 1980, after a severe outbreak of flu.
1980年在一场严重的流感爆发后，平均寿命也曾有所下降。
Overall life expectancy for men and women is now 78.8 years, a decrease of 0.1 year from 2014.
目前，男性和女性总体平均寿命为78.8岁，比2014年降低了0.1岁。
"This is unusual," lead author Jiaquan Xu, an epidemiologist at the NCHS, told AFP news agency. "2015 is kind of different from every year.
“这不正常。”国家卫生统计中心的流行病学家许佳权告诉法新社。“2015比起往年来略有不同。”
"It looks like much more death than we have seen in the last few years."
“这一年比往年的死亡率更高。”
The report is based mainly on 2015 death certificates.
该报道主要基于2015年的死亡证明文件。
It showed death rising death rates for heart disease - the leading cause of death, as well as chronic lower lung disease, accidental injuries, stroke, Alzheimer’s disease, diabetes, kidney disease and suicide.
这表明心脏病造成的死亡率升高——而这是死亡的主要因素，除此之外还包括慢性肺部疾病、意外伤害、中风、阿尔茨海默症、糖尿病、肾病以及自杀。
But while all of those rose by 3% or less, deaths from Alzheimer’s disease rose 15.7% in a single year, and there was an 11.3% increase in the rate of death for babies under one due to unintentional injuries.
这些因素综合起来，使得死亡率上升3%左右，然而这一年阿尔茨海默症导致的死亡率上升了15.7%；一岁以下儿童由于意外伤害造成的死亡率上升了11.3%。
"The only good news we see in 2015 was that the cancer death rate continued to decrease," said Jiaquan Xu.
“2015年唯一的好消息就是癌症死亡率持续下降。”许佳权说。
