Science & Technology

New air filter technology found to deactivate over 99% of SARS-CoV-2 delta variant

Innovative antimicrobial air filter uses ingredients found in green tea

By Nandita Banerji
Published: Tuesday 20 December 2022
Photo for representation: iStock
Photo for representation: iStock Photo for representation: iStock

A team of researchers from the Indian Institute of Science (IISc), Bengaluru have developed air filters made of ingredients commonly found in green tea. The antimicrobial filters can destroy germs and remove them from their system. 

The novel antimicrobial air filters were tested at an accredited laboratory. They were found to deactivate the delta variant of SARS-CoV-2 with an efficiency of 99.24 per cent. The innovation holds promise to develop antimicrobial filters that can prevent epidemics by air-borne pathogens. 

Read more: Can Bio-CNG click: Indore plant reducing air pollution, but odour remains a challenge

The newly developed filters can inactivate germs using ingredients like polyphenols and polycationic polymers commonly found in green tea. These ‘green’ ingredients can rupture the microbes through site-specific binding, according to a press note December 17, 2022

The research was led by professors Suryasarathi Bose and Kaushik Chatterjee of the varsity. Special grants from a statutory body under the Centre, Science and Engineering Research Board (SERB), during the COVID-19 pandemic supported the research. The tech was granted a patent this year. 

A comparison of microbial growth between the new filter and a normal one. Photo: Press Information Bureau

Over continuous usage, the existing air filters become a breeding ground for captured germs. The growth of these germs clogs the filter’s pores, reducing its life. Resuspension of these germs can infect people in the vicinity. 

These novel antimicrobial filters in our air conditioners, central ducts and air purifiers can play a crucial role in our fight against air pollution and mitigate the spread of air-borne pathogens like coronaviruses. 

This technology was transferred to AIRTH, a startup that is replacing the existing germ-growing air filters with germ-destroying air filters for commercialisation.

Read more: Why Delhi continues to choke year after year

Air pollution can have severe effects on health. A recent study found that countries with higher rates of stillborn babies had higher amounts of fine particulate pollution. 

India led the list with the highest average number of stillbirths — 217,000 out of 25 million births each year. South Asia, sub-Saharan Africa and the Arabian Desert were hotspots of PM 2.5-related stillbirths due to high exposure and baseline stillbirth rate, it further found.

India had an average drop of 3.86 years in life expectancy due to air pollution, which caused 1.8 million premature deaths in 2015, according to a March 2020 study. 

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