壹份新的研究表明，那些乘出租車、汽車和小轎車的人比那些騎自行車和步行的人吸入更多的汙染物。研究者用壹種新發明的帶攝像機的粒子計數器來測量繁忙的倫敦大街上由交通工具產生的極小的粒子層次。
The equipment allowed them to match particle levels with each of the five modes of transport. They also could identify what activities and behaviors lead to the highest exposures(暴露). On average, taxi passengers were exposed to just under100,000 and people in cars about 40,000.
這種設備可以將各種粒子層次分別與五種運動形態想匹配，還能夠識別何種活動和行為能引起最高的汙染度（曝光率）。壹般說來，乘出租車的人暴露在十萬單位的汙染物中，乘小轎車的乘客暴露在四萬單位的汙染物中。
Pedestrians and bicyclists, meanwhile , were exposed to counts of just 5 ,000 and 8 ,000 , respectively. Ultra-fine particles are so small that large amounts can be breathed in a single breath, after which they can settle in the lungs and damage cells.
與此同時，騎自行車和步行的人們則分別暴露在僅5000和8000單位的汙染物中。
細微粒子由於體積太小，所以人們會在單次呼吸中就吸入大量的汙染物粒子，這些粒子會停留在肺中損傷細胞。
Would the results hold true in New York City or elsewhere? We generally found that the trends such as pedestrians having the lowest exposures and the in-vehicle exposures being much higher to be common across different countries,” study co-author Surbjit Kaur of Imperial College London said, “However, the concentrations(濃度) do vary due to different local conditions, such as traffic, meteorology, building layout, and configuration. “
在紐約或者其他地方會跟倫敦有同樣的結果嗎？倫敦帝國學院的合作研究人說：“我們發現壹個普遍的現象，雖然在不同國家，但是步行者總是生活在汙染粒子濃度最小的地方，而交通工具內的汙染濃度就要高得多。然而，汙染物的濃度確實會因當地條件不同而有所差異，這些條件包括交通狀況、氣象因素、建築設計和城市布局。”
People sitting in a vehicle in the middle of heavy traffic are directly in the path of the pollutant source---other vehicle’ s mufflers. Pollution in cars is less than in other vehicles most likely because cars generally spend less time in traffic than taxis and buses, Also, private cars tend to be cleaner to begin with.
那些在交通繁忙地段車中的人們，就直接暴露的汙染源之中，汙染源就是其他車輛的煙筒。轎車中的汙染會比其他車輛的汙染度輕壹些，主要是因為轎車在路上的時間比出租車和公車少很多，而且私家車在使用之前也比其他車幹凈得多。
Bikers stick mostly to the outer edges of the street, where pollution levels are lower. People on the sidewalk are even further away.
自行車行者基本都是在汙染程度低得多的街邊，而步行者就更加遠離汙染。