BJP supremo Amit Shah to visit Mangaluru on Oct 4

Madikeri, Apr 22: The quality of water in the River Cauvery in Kodagu district has improved significantly following the nationwide Lockdown.

The discharge of effluents from home stays and resorts situated on the banks of the river in the district has stopped due to lack of visitors. The discharge of waste water had made the river impure all these years.

The suspension of boat ride in Dubare has reduced the pollution from diesel motorboats in the river. For the last few years, the water quality of the river had reached 'C' category from 'B' category during the summer.

Bengaluru, Apr 5: The COVID-19 related lockdown has substantially improved the air quality of Bengaluru, taking it from satisfactory level to good, a senior state pollution control board offcial said here on Sunday.

"During the course of the lockdown 19 problem, we reached good position from satisfactory.

It is between zero to 50 AQI (Air Quality Index) now. We have good quality air," the Karnataka State Pollution Control Board member secretary Basavaraj Patil told PTI.

He said the indicator for knowing the air quality in

"If the AQI is zero to 50 then it is good. If it is 50 to 100 then it is satisfactory. 101 to 150 is moderate and if it is 151 to 200, then it is poor, he explained.

Patil said as per available recrods, there has been a 60 to 65 per cent reduction in pollution during the lockdown.

The city railway station and Peenya industrial area, which used to be among the areas with highest AQI, has seen pollution levels come down significantly, he said.

Another major contributor of pollution was construction activities, which too had ground to a halt due to the lockdown, resulting in zero dust emission.

Patil opined that the improved air quality would boost the immune system of the people.

"It will improve the immune system of people, including those who have breathing problems like asthma," he said.

He asked the public to learn lessons from the lockdown and later switch to sustainable means of transport such as public transport, walking and cycling,.

"We can still reduce the pollution load even after the lockdown is over," Patil said.

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.