Air pollution from nitrogen dioxide has fallen by an estimated 40% in three European cities, according to new satellite data released by the European Space Agency (ESA), coinciding with a widespread lockdown to curb the spread of the coronavirus.
欧洲航天局发布的新的卫星数据显示，为了阻止冠状病毒传播多地封城期间，据估计在三个欧洲城市中，二氧化氮造成的空气污染下降了40%。
The space agency's Copernicus Sentinel-5P satellite mission on Friday released three composite images showing nitrogen dioxide concentrations in the period March 14-25 over France, Spain and Italy, compared to the monthly average of concentrations from 2019.
欧洲航天局的哥白尼哨兵-5p卫星任务在周五发布了三个合成图像，显示了3月14日至25日期间法国、西班牙和意大利的二氧化氮浓度，与2019年的月平均浓度做了对比。
"This is a first level estimate; some of these values have gone down by about 40% of the normal value... so a very drastic decrease," Josef Aschbacher, ESA Director of Earth Observation Programmes, told Reuters via a video call.
欧洲航天局地球观测项目主任Josef Aschbacher在视频通话中对路透社说：“这是一级估值，其中一些数值与正常值相比下降了约40%，下降幅度竟如此之大。”

Researchers studying the impact of emissions from industry and transport on climate change and human health are scrambling to understand the possible implications of the coronavirus pandemic as economies slow, flights are disrupted and quarantines imposed.
目前经济放缓，航班被迫取消，还要实行隔离，研究工业和运输排放对气候变化和人类健康影响的研究人员正在尽力了解新冠疫情可能产生的影响。
"What you really see are the centers of this pollution... It is quite a good first level indicator of anthropogenic pollution coming from traffic and industry," added Aschbacher.
Aschbacher补充说：“你真正看到的都是污染中心。这是交通和工业产生的人为污染的很好的一级指标。”
Nitrogen dioxide, a noxious gas emitted by cars, power plants and factories, is blamed for some respiratory and heart conditions.
二氧化氮是汽车、发电厂和工厂排放的有毒气体，会导致呼吸和心脏疾病。
Almost every city-dwelling European is exposed to pollution levels that exceed healthy levels, according to a 2019 report from European Environment Agency (EEA).
2019年欧洲环境署的一份报告显示，几乎所有在城市居住的欧洲人身边的污染程度都超过健康水平。