The level of air pollution in London, Rome, Milanand Paris has fallen sharply since coronaviruslockdown measures have forced people indoors andoff the roads.
Levels of particulate matter, which can come fromroad transport and burning fuel, as well as nitrogendioxide, which comes primarily from vehicleexhausts, are low across London.
在倫敦,來自公路運輸和燃料燃燒的顆粒物,以及主要來自汽車尾氣的二氧化氮的含量都很低。
The UK capital's levels of ultra-fine particulate matter, known as PM2.5, are currently aroundhalf that would be normally recorded at this time of year.
目前,倫敦的超細顆粒物(PM2.5)水平約為往年同期正常水平的一半。
The city's level of nitrogen dioxide has also been lower than the average for the previous fiveyears, scientists say.
科學家表示,倫敦空氣中的二氧化氮水平也低于過去5年的平均水平。
Both pollutants have fallen by around a half since a peak in mid-February, according to datafrom the London Air Quality Network, analysed by the National Centre for Atmospheric Science.
Meanwhile, European Environment Agency (EEA) data confirmed a 50 percent decrease in airpollutant concentrations in Rome and Milan.
與此同時,歐洲環境署的數據證實,羅馬和米蘭的空氣污染物濃度下降了50%。
A Paris air quality monitoring agency has also recorded up to a 30 percent decline in overallair pollution levels there.
巴黎一家空氣質量監測機構的數據顯示,巴黎的整體空氣污染水平下降了30%。
As daily life grinds to a halt in the UK due to restricted movement to control the spread ofCOVID-19, air quality has improved due to a sharp reduction in traffic.
'Air quality has started to improve in many UK cities, mirroring what has been seen in othercountries that have restricted travel and levels of outdoor activity,' said Professor AlastairLewis, from the National Centre for Atmospheric Science, University of York.
'This is primarily a consequence of lower traffic volumes, and some of the most clearreductions have been in nitrogen dioxide, which comes primarily from vehicle exhaust.
“這主要是交通流量減少的結果,而二氧化氮的減少最為明顯,二氧化氮主要來自汽車尾氣。”
'However fine particles (PM2.5) have also reduced significantly.
“不過,PM2.5也顯著減少。”
'In London for example, PM2.5 is noticeably lower than would be expected for this time of yearat the roadside, and these reductions stretch through into the suburbs as well.'
“以倫敦為例,路邊的PM2.5濃度明顯低于往年同期水平,而且郊區也出現了這種下降趨勢。”
Professor Lewis said it's especially important to consider how PM2.5 levels have changedcompared to what is normally seen at this time of year.
劉易斯教授表示,目前尤為重要的是要思考PM2.5水平與往年同期相比發生了怎樣的變化。
While nitrogen dioxide is mainly emitted from vehicle exhausts, sources of particulate matterare more varied, ranging from road transport to burning fuel.
雖然二氧化氮主要來自汽車尾氣,但顆粒物的來源更為多樣,包括道路運輸和燃燒燃料等。
Air pollution is linked to health problems including stroke, heart disease, lung cancer anddisease, and respiratory diseases and infections, as well as stunting the growth of children'slungs.
Professor William Collins, professor of meteorology at the University of Reading, said a largeamount of the air pollution that is breathed in comes from traffic.
雷丁大學氣象學教授威廉·柯林斯表示,人們吸入的空氣污染物主要來自交通污染。
And as levels of traffic pollution have plummeted with many countries in lockdown, exposureto pollutants is reduced by people staying off the streets and in their homes.
隨著多國實行封閉措施,交通污染水平大幅下降。人們遠離街道并待在家里,減少了接觸污染物的機會。
France's stay-at-home orders to combat the coronavirus outbreak have produced a 20 to 30percent decline in overall air pollution levels in Paris, according to a report from the region'sair quality monitoring agency.
France's lockdown has taken countless cars and delivery trucks off the roads since coming intoeffect on March 17, and massively reduced the number of flights at the two airports serving thecapital.
The Airparif report said that just two days after the self-confinement began, it registered 'a 20to 30 percent improvement in air quality in the Paris metropolis, after nitrogen oxideemissions dropped by more than 60 percent.'
The European Environment Agency's (EEA) data has confirmed a large decrease in airpollutant concentrations - in particular of nitrogen dioxide (NO2).
歐洲環境署的數據證實了空氣污染物濃度的大幅下降,尤其是二氧化氮。
NASA satellite images have already revealed dramatic reductions in concentrations of nitrogendioxide in China and northern Italy, coinciding with lockdowns there.
美國國家航空航天局的衛星圖像顯示,在各國實施封鎖期間,中國和意大利北部的二氧化氮濃度大幅下降。
Other footage from the European Space Agency Copernicus satellite reveals a 'notable drop' inair pollution over Italy after the coronavirus lockdown.