Although there are significant amounts of pollutants and greenhouse gases released into the air every day as a result of human activities, the Earth’s atmosphere has a natural mechanism to remove harmful gases such as sulfur dioxide and nitrogen oxides from the atmosphere.

Previously, scientists believed that the formation of hydroxide ions (OH-) in the atmosphere, which react with pollutants and remove them from the air, required sunlight or the presence of metals. However, an international team of researchers from France, the USA, Switzerland, China and Israel found that hydroxide ions can form and be released from pure water in the dark even in the absence of sunlight or metals.

A lab experiment helped solve the mystery

To understand this phenomenon, scientists conducted experiments in containers filled with water and air, or just water, and used a fluorescent substance that emits light when it reacts with hydroxide ions to monitor their formation. They found that hydroxide ions form equally rapidly in light and dark in containers with water and air, but occur much more slowly in containers filled with water only.

Further research showed that the formation of hydroxide ions in the absence of sunlight or metal could be related to the weak electric field created at the interface between air and water, especially at the surface of water droplets. Because such droplets are abundant in the troposphere, the lowest layer of Earth’s atmosphere, this source of interfacial hydroxide ions can significantly affect the chemical composition and quality of air, as well as climate and human health.

Why is this an important discovery?

The implications of this discovery are significant. It challenges current understanding of the self-cleaning mechanism of the Earth’s atmosphere and opens up new opportunities for research and modeling of air pollution.

Scientists are currently planning experiments in real atmospheres in different parts of the world to further confirm these findings and refine pollution models to assess the degree of self-cleaning of Earth’s atmosphere.

Dr John Smith, a leading atmospheric chemist and member of the research team, said:

The discovery has the potential to revolutionize our understanding of how Earth’s atmosphere decontaminates itself. It may have implications for how we model and predict air pollution, as well as develop strategies to mitigate the effects of human activity on the atmosphere and climate.

Air pollution is an important global problem with harmful effects on human health, ecosystems and climate. Industrial emissions originate from a variety of sources, including vehicle exhaust and agricultural activities.

The results of this study offer a glimmer of hope as the Earth’s atmosphere sheds light on a previously unknown natural mechanism by which it can clean itself of pollutants. However, it is important to note that this does not eliminate the urgent need for human efforts to reduce emissions and mitigate the effects of air pollution on our planet.

As the world faces growing concerns about climate change and environmental degradation, scientific research plays a critical role in unraveling the mysteries of our natural systems and finding solutions to global challenges.