Angela Merkel has urged Germans to open their windows to fend off a disastrous second wave of coronavirus.
The chancellor said good ventilation could be ‘one of the cheapest and most effective measures’ to slow the rate of infection as gloomier weather forces people indoors.
Scientists say well-ventilated rooms are less vulnerable to the spread of Covid-19 because indoor air that is contaminated with infectious droplets is replaced with fresh air.
German authorities suggest ‘intensive ventilation’ if somebody starts coughing or sneezing at work as the country battles a gradual rise in cases and deaths.
Germany is battling a gradual rise in cases which has taken the daily average to nearly 2,000 a day, with Merkel warning that the figure could reach 20,000
Deaths have also risen slightly although Germany’s overall fatality rate is still substantially lower than in many Western European countries
The new recommendation is one of the latest measures agreed by Merkel’s cabinet and the country’s 16 state governments to tackle a possible second wave.
Ventilation has been added to Germany’s five-step hygiene advice along with social distancing, hand-washing, mask-wearing and using the coronavirus app.
‘The basic rules remain the same – keeping a 1.5m distance and covering your mouth and nose,’ Merkel told a press conference.
‘In addition, we have to take ventilation very seriously because so many things are taking place indoors.
‘People often laugh about it, but it could be one of the cheapest and most effective measures to slow or halt the spread of the pandemic.’
Airing homes is a common preoccupation in Germany in any case, with people urged to open their windows in winter to avoid mould.
But it has taken on new significance this year with Germany’s environment agency calling for the ‘highest possible supply of fresh air’ to avoid the spread of Covid-19.
The Covid-19 virus is thought to spread through droplets which are produced when an infected person coughs, sneezes, talks or even sings.
These droplets can land in others people’s mouths or noses, or get there via their unwashed hands.
Scientists have found that the droplets remain airborne for longer in poorly-ventilated spaces, increasing the risk of transmission.
Angela Merkel (pictured in the German parliament on Wednesday) said good ventilation could be one of the cheapest and most effective ways of preventing the spread of Covid-19
Writing in medical journal The Lancet in July, researchers said their findings ‘confirm that improving ventilation of public spaces will dilute and clear out potentially infectious aerosols’.
‘We believe health-care authorities should consider the recommendation to avoid poorly ventilated public spaces as much as possible,’ they wrote.
The German environment agency suggests opening ‘several windows in one room at the same time’ if possible to achieve the most effective ‘cross-ventilation’.
‘Should individuals be coughing and sneezing, whether at home, in the office or at school, intensive airing should be carried out immediately,’ it says.
‘In high-occupancy rooms, mere tilting of the windows is considered rather ineffective, even if it is constant.’
The issue is likely to become more prominent as colder and wetter weather prevents people from socialising outdoors in the coming months.
The virus is thought to spread less outdoors, not only because people can keep further apart but also because of the ‘unlimited dilution’ of viral particles in a breeze, as one Harvard researcher described it.
Robert Hickson, a New Zealand-based biologist, wrote last month that ‘most clusters of transmission outside of households are associated with “3Cs”: closed spaces with poor ventilation, crowded places, and close-contact settings’.
The Covid-19 virus is thought to spread through droplets which can remain airborne for longer in poorly-ventilated rooms (stock photo)
In Germany, Merkel and the state leaders have also agreed to restrict the size of gatherings and to fine anyone who flouts tracking rules in an effort to contain the spread of the virus.
The chancellor said Germans had so far done well to obey the rules but urged them to keep their discipline to avoid a second lockdown.
‘I am sure that life as we knew it will return, families will celebrate again, and clubs, theatres and football stadiums will be full again,’ she said. ‘And what a joy this will be.’
Merkel said her government wants to keep the economy running as far as possible and keep children in schools and kindergartens during the pandemic.
However, she has warned that the country could reach nearly 20,000 cases per day by Christmas if the current rising trends continue.
The current average is 1,950 cases per day, but that has risen from 1,500 only two weeks ago and deaths have also increased.
Germany’s closely-watched R rate has been above the critical threshold of 1 for much of the last few weeks as cases gradually mount.
However, the resurgence has so far been far less severe than in neighbouring France, or in Spain which has suffered the worst rebound in Europe.
Germany’s current totals are 291,722 cases and 9,500 deaths.