Is it safe to eat inside restaurants?
COVID-19 numbers are low in Australia and new measures encourage outdoor dining to offer the battered hospitality sector a kickstart.
But doubts remain about the safety of enclosed indoor spaces.
ABC science reporter Belinda Smith experienced the spike in cases in the UK after it urged the populace to ‘Eat Out To Help Out’ in July. The four-week campaign subsidised half the cost of meals and non-alcoholic drinks (up to £10 or $18 per person) on Mondays, Tuesdays and Wednesdays.
“Areas with higher take-up (of Eat Out to Help Out) saw… a notable increase in new COVID-19 infection clusters within a week of the scheme starting, and again, a deceleration in infections within two weeks of the program ending,” said Dr Thiemo Fetzer from the University of Warwick.
Charlotte Jee, writing for MIT Technology Review, explains why there was confusion about indoor safety.
“The official line from the World Health Organization from the start of the pandemic has been that the coronavirus is mostly spread by the droplets we generate as we talk, sneeze, or cough. However, the evidence has been mounting for months now that aerosols – which are smaller than droplets and can hang in the air like smoke – are a significant route for infections, if not the main one. This would explain why virtually every recorded coronavirus outbreak has occurred indoors.”
Public Health England found that amongst people who tested positive for the coronavirus in the past two months, “eating out was the most commonly reported activity in the two to seven days prior to symptom onset”.
Scotland’s government reported a quarter of people returning positive tests for COVID-19 had been to a restaurant, pub, or cafe in the week before. A Centers for Disease Control and Prevention (CDC) study of 802 adults in the US found that people who tested positive for COVID-19 were twice as likely to have reported dining at a restaurant than those who tested negative.
And last week, a study published in Nature concluded that (indoor) restaurants are the riskiest setting for transmission of the coronavirus.
“The risk of infection is 20 times higher inside than outside,” says Bjorn Birnir, director of UC Santa Barbara’s Center for Complex and Nonlinear Science.
“Eating indoors in a restaurant is a higher risk activity,” says Dr. Anne Liu, an infectious disease specialist at Stanford Health Care.
“Several risk factors are coming together with indoor dining: being indoors, prolonged conversations and frequent mask removal. Until someone invents a mask that you can eat in, while still capturing respiratory droplets, that risk remains.”
Ali Patillo, writing for inverse.com, explained it this way: “To date, scientists don’t know exactly how much eating out (or in) is contributing to COVID-19 transmission. They do know indoor dining presents an elevated risk of catching and spreading COVID-19, compared to eating outside or at home.
“That’s because when a person infected with COVID-19 breathes, coughs, sneezes, talks, or sings, they spray respiratory droplets into their immediate vicinity. Some of these potential coronavirus containing droplets fall immediately to the ground, end up on surfaces, or linger and then evaporate in the air. Others land on the eyes, noses, or mouths of others, or are inhaled.”
Eater.com notes that the CDC recently updated its coronavirus webpage, acknowledging that it’s possible for the virus to be spread by airborne transmission. The update notes that infectious particles can “linger in the air for minutes to hours” and that past airborne transmissions “occurred within enclosed spaces that had inadequate ventilation”.
“Being in an enclosed space where air is recirculated means that if there are viruses suspended in those aerosols in a room, the longer you spend time unmasked in an enclosed space, the higher the risk of contracting the virus,” says Dr Russell G. Buhr, a pulmonary and critical care physician at UCLA Health.
“The way that people get infected is a combination of how long they are in close proximity to an infectious source, coupled with how much virus they are exposed to.”
Researchers don’t yet know how much exposure to the virus infects us. The current estimate is that just 15 minutes of proximity can do it.
“A poorly ventilated indoor space with people talking is the virus’s dream,” said Lindsey J. Leininger, a clinical professor at the Tuck School of Business at Dartmouth College.
But if you must dine indoors, take some advice from diners still living with high infection rates:
New York Times advice for indoor dining
The risk of coronavirus transmission is lower for outdoor than for indoor dining in almost every case, and the safest course of all is staying at home. But if you do decide to eat inside a restaurant, try to go at an hour when it’s less crowded. Before you sit down, take a quick look around. If the management doesn’t seem to be taking things like airflow and masks seriously, public health experts suggest eating somewhere else.
You should leave if you notice:
- stuffy, stale air
- crowds standing around the host station or anywhere else. (Outdoor host stands are a good idea)
- tables that are too close together. The distance between customers who aren’t seated together should be at least 1.5m, although some experts, like Linsey Marr, a professor of civil and environmental engineering at Virginia Tech, recommend twice that
- noise. People who talk when not wearing a mask are a risk. People who talk loudly, shout or sing without a mask are a bigger risk
- servers who linger at the table, or who drop their masks at any time.
Consider staying if you see:
- windows and doors that are open to let in fresh air
- window fans that face out. (Beware of fans that face in and of floor fans, which could move virus-laden particles around the dining room)
- portable air purifiers with HEPA filters
- movable partitions, although they are not an invincible force.
Are you attending restaurants? Do you feel they are safe? Have you seen restaurants which have taken measures against the coronavirus?
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