As coronavirus continues to spread, some governments have restricted travel while, elsewhere, individual travellers have been taking their own precautions.
The BBC has been receiving questions about whether it is safe to fly, go on a cruise or take public transport.
Trains and buses
It’s not yet known exactly how coronavirus spreads, but similar viruses are caught from either breathing in droplets from an infected person’s coughs or sneezes, or touching surfaces with them on.
We think that coronavirus probably doesn’t hang around in the air in the same way as flu does, so, people need to be in closer contact with each other to catch it. The NHS guidance on coronavirus defines “close contact” as being within two metres of an infected person for more than 15 minutes.
So a lot of the potential risk of infection on trains and buses depends on how crowded they are, and this will vary in different parts of the country and on different routes.
It’s a common belief that you are more likely to become ill on an aeroplane, because you’re breathing “stale” air.
In fact, the air on a plane may well be better quality than in the average office (and almost certainly better than a train or a bus).
There are more people per square foot on a busy plane, which can increase the risk, but the air is also being changed at a faster rate.
Professor Quingyan Chen at Purdue University, who studies air quality in different passenger vehicles, estimates that the air on a plane is completely replaced every 2-3 minutes, compared with every 10-12 minutes in an air-conditioned building.
That’s because while you are on a plane, the air you breathe is being cleaned by something called a high-efficiency particulate air filter (Hepa). This system can capture smaller particles than ordinary air-conditioning systems, including viruses.
The filter sucks in fresh air from outside and mixes it with the air already in the cabin, meaning that at any one time half the air is fresh and half is not. Many ordinary air-conditioning systems merely re-circulate the same air to save energy.
Source: BBC News