There is at least one atmospheric region on Earth that has been unchanged by human-related activities, and a research group from Colorado State Univeristy (CSU) has found where it's located.
This first-of-its-kind study measured the bioaerosol composition of the Southern Ocean, near Antarctica, and found that it has the cleanest air on Earth.
Their findings were published in the journal Proceedings of the National Academy of Sciences (PNAS) on Monday.
Weather and climate
Professor Sonia Kreidenweis and her team at CSU suspected that the air near Antarctica could be the least affected by humans, and they were right. It's a struggle for researchers and scientists to find regions on Earth that aren't affected by human-related climate change, so this is a one-of-a-kind study.
The researchers discovered that the boundary layer air, which feeds the lower clouds over the Southern Ocean, was in fact free from aerosols caused by human activity. These aerosols — solid and liquid particles and gases suspended in the air — include burning fossil fuels, certain crops planted, fertilizer production, and wastewater disposal — all of which create air pollution.
The team studied what was in the air, where it came from, and used bacteria in the air as a diagnostic tool to find out what made up the lower atmosphere in the region.
Co-author of the study, Thomas Hill, explained "the aerosols controlling the properties of SO (Southern Ocean) clouds are strongly linked to ocean biological processes, and that Antarctica appears to be isolated from southward dispersal of microorganisms and nutrient deposition from southern continents."
Hill added "Overall, it suggests that the SO is one of the very few places on Earth that has been minimally affected by anthropogenic activities."
The team also sampled the air that has direct contact with the ocean while they were aboard a research boat traveling to the Antarctic ice edge, south of Tasmania in Australia. The team then analyzed the airborne microbes, which are usually dispersed thousands of kilometers by the wind.
It turns out that air that far south doesn't come from polluted, more northern, regions.
In their study, the team described the air as "truly pristine."
Air pollution kills around seven million people per year as per the WHO, and it has been shown to increase the risks of heart disease, stroke, and lung cancer, and even shortening people's lives by three years.