Mumbai: Why indoor dining carries a high risk of Covid-19 spread? – Hindustan Times

As Mumbai unlocks further, citizens were hopeful for more relaxation in the timings of restaurants. But the city’s administration has refrained from extending the dine-in hours. Reason: Indoor dining, mainly in air-conditioned, closed spaces is considered high risk for the transmission of Covid-19.

“Restaurants are the only places where unmasking is involved. This is perhaps why the restrictions on restaurants continue in the city,” said Dr Shashank Joshi, member of the Covid-19 task force of Maharashtra.

Currently, restaurants are allowed to remain open for dine-in services only up to 4pm on weekdays. After the first lockdown, restaurants implemented many innovative ways for a limited-contact experience for their customers. Digital food menus, staggered seating, reduced occupancy were some of the measures that were introduced. But a crucial aspect could not be changed — the air conditioners.

“In an air-conditioned space, the same air keeps circulating in the enclosed space,” said Rajneesh Bhardwaj, associate professor, department of mechanical engineering at Indian Institute of Technology-Bombay (IIT-B). “The concentration of particles in this air is higher, which makes it risky, he said.

According to Bhardwaj, closed, air-conditioned eating spaces carry a high risk of infection spread. “The risk may go down slightly in non-air-conditioned, well-ventilated spaces and it further reduces in open air space. We should not forget that there will always be a heightened risk when one does not wear a mask and the virus continues to be in circulation,” he said.

A 2020 research paper published in the Journal of Korean Medical Science that studied a restaurant setting said that droplet transmission can occur at a distance greater than 2 metres (6 feet) if there is direct airflow from an infected person in an indoor setting.

The Centers for Disease Control and Prevention has stated that being outdoors and in spaces with good ventilation reduces the risk of exposure to the virus. It also suggests increasing the circulation of outdoor air as much as possible, for example, by opening windows and doors and prioritising outdoor seating.

Medical experts say the best time to introduce relaxations for restaurants is when the city achieves nearly 70% full vaccination coverage. As more people get vaccinated, it will create safer environments for eateries and restaurants.