Ozone Layer Current Affairs - 2020

United Nations: Nitrogen Dioxide levels fell by 70% in Delhi

On July 28, 2020, the United Nations reported that the nitrogen dioxide levels in New Delhi has fell by more than 70% during the lock down. However, according to the international organization, this could be temporary till the cities re-open.


The Nitrogen Dioxide levels has fallen down in other countries as well. In China the levels have fell by 40%, in Belgium, it fell by 20%, between 19-40% in USA.

Why is Nitrogen Dioxide harmful?

The Nitrogen Oxides reduce the air quality. It depletes ozone layer (the stratospheric ozone) by combining with ammonia via particulate matter. It also increases human health risks like cancer and other respiratory diseases. The Nitrogen oxides can get converted into nitric acid and causes acid rain. Acid rains are highly harmful as they leech into under ground surfaces contaminating ground water.

Ground level Ozone and Nitrogen Dioxide

Around 90% of total ozone is present in the Stratosphere. 10% is found in troposphere and is less concentrated than that of stratospheric ozone. The Ground level Ozone is created by the chemical reaction between organic compounds and nitrogen oxides. Since ozone is a greenhouse gas, it contributed to global warming. Thus, it is essential to control nitrogen oxides in the atmosphere.

DHRUVs: UV based Sanitizer by DRDO to sanitize phones

The Research Centre Imarat (RCI) of Defence Research Development Organization (DRDO) has developed Defence Research Ultraviolet Sanitizer (DHRUVS).


The RCI of DRDO based in Hyderabad has developed a Ultra Violet Cabinet to sanitize mobile phones, laptops, iPads, passbooks, challans and paper. It can also be used to sanitize currency notes and papers. It provides 360-degree exposure to UV rays to the objects placed inside the cabinet.

DHRUV is a contactless ultraviolet sanitization cabinet that is highly useful to sanitize electronic gadgets.

How does UV kill virus?

After the spread of COVID-19, several UV technologies have emerged to disinfect the daily use objects. In China, buses are being disinfected with UV light technology every night after their use.

The technology where Ultra Violet is used as disinfector is called Ultra Violet Germicidal Irradiation (UVGI). The UV light is weak on the earth’s surface as it is blocked by sunlight. Also, UV light is harmful to humans.

The short wavelength UV are generally the germicidal UV. They are between the wavelength 200 nm and 300 nm. They are highly absorbed by nucleic acids. When absorbed, the nucleic acids lose their capability of replication. Also, the nucleic acid disintegrates shortly leading to death of the organism.