BreakingNews·200606-Scientists discover the world's cleanest air

00:00

00:00

MP3下載

https://online2.tingclass.net/lesson/shi0529/10000/10339/200606.mp3

https://image.tingclass.net/statics/js/2012

Scientists discover the world's cleanest air

Scientists have discovered what they believe to be the cleanest air on Earth. Researchers from Colorado State University and the Australian Bureau of Meteorology conducted research on the purity of the air above Antarctica. They found a region over the Southern Ocean, between the south of Australia and Antarctica, that was "unaffected" by human activity. The scientists said the area they researched formed the atmosphere in the lower clouds. The analysis of the air showed that it was totally free from "anthropogenic aerosols". These are pollutants or particles derived from human activity, or dust from other continents. The scientists called this pollution-free area, "truly pristine".

The scientists analysed the structure of airborne microbes in the lower clouds over the Southern Ocean. They looked at the DNA of the microbes and tracked where they came from. Their analysis included monitoring wind trajectories to detect how far the microbes may have travelled. They found that the atmospheric eco-system was very much "isolated," self-contained, and free from contaminants from elsewhere in the world. The source of the microbes was the Southern Ocean, rather than airborne pollutants from other continents. The researchers concluded that the Southern Ocean is one of very few places on Earth that has been "minimally affected by anthropogenic activities."