Trains are safer than planes

Air circulation and filter : Are you safer from Corona on a plane than on the train?

Two suspected cases, 1200 passengers: Corona alarm was triggered on the "Aida Aura" in Norway. The two guests came into contact with a corona patient a week ago. "All passengers remain on board," announced the German cruise line on Tuesday. It was a false positive. The journey continues now, but the nervousness in the industry remains.

600 passengers on the "Diamond Princess" had previously contracted the coronavirus off the Japanese coast, and seven patients have died so far. The infection rate on board the ship was four times higher than in severely affected corona areas on land, according to a first study by the Swedish Umeå University. One of the reasons for this could possibly have been the ventilation systems on board.

“Cruise ship air conditioning systems mix outside air with inside air to save energy. The problem is that these systems cannot filter out very small particles. If the coronavirus was about the same size as Sars, the air conditioning would put the virus in every cabin, ”said Qingyan Chen. The professor at Purdue University in the United States researches the spread of viruses and bacteria in different modes of transport.

The initial situation is similar in rail traffic. "Most trains also use a mix of circulated and fresh air from outside, whereby the most frequently used filter systems cannot efficiently remove the smallest corona particles," said Chen Tagesspiegel Background. Only the so-called Hepa filters could do that, but they are not used in trains, ships, buses or subways.

Airplane air as clean as in the operating room?

Hepa stands for high-efficiency particulate air and is said to be able to filter even the smallest virus particles out of the air. Such systems have so far only been used in aircraft for means of transport. “The degree of separation of these filters corresponds to the standard of the filters in a clinical operating room,” says Lufthansa, “in addition, the air flow in aircraft takes place from top to bottom. There is no horizontal air flow sideways or in the longitudinal direction ”.

In the aircraft, the risk of transmission depends on other factors, such as how many passengers come very close to you - and, above all, what you touch. Studies show, for example, that the risk of infection is lowest in window seats and highest in aisle seats. According to the World Health Organization (WHO), only those passengers who are up to two rows of seats away are considered to be "contact persons" in suspected corona cases on board. Other researchers, however, are more cautious.

It is better not to touch anything in any of the seats without prior disinfection, if you are risk-averse: the folding tables on the front seat are particularly contaminated with bacteria, according to studies. And even after buckling up, it can be worth disinfecting your hands. The risk naturally rises again in the toilets, which also applies to trains and long-distance buses.

New York wants to completely disinfect the subway

Rail and bus operators as well as shipping companies whose means of transport do not have Hepa filters should, if possible, set the air conditioning and ventilation systems during the spread of the corona so that one hundred percent fresh air flows into the cabins and no circulated air, urges US researcher Qingyan Chen. Without the circulating air, only the temperatures could be a bit too high or too low.

The air conditioning is only one of many factors, which is why it cannot be said in general that this or that means of transport is riskier than others. The WHO, for example, has not yet rated the risk of infection on cruise ships as higher than in other places with large crowds, which is why the same precautionary measures should apply there as elsewhere. At airports, on the other hand, there are often standard fever controls, but hardly any at stations outside of particularly affected areas.

Local transport providers are reacting to the spread of corona by increasingly disinfecting buses or subways. In New York, the Metropolitan Transportation Authority (MTA) announced on Tuesday that it would disinfect all subways and buses every 72 hours. Turnstiles and ticket machines are to be cleaned daily at more than 700 stops. So far there is one confirmed corona patient in the city

Tesla advertises with "Bioweapon Defense Mode"

With the Geely Group, a first car manufacturer has announced the introduction of the new IAPS air conditioning system in response to the coronavirus outbreak, which stands for Intelligent Air Purification System and which has been installed in new vehicles since the beginning of March. It was developed in 20 days and can filter viruses and bacteria out of the air, according to the company, but is only a first step. Further developments are to follow.

The first 150 cars are used as emergency vehicles in corona crisis centers. The IAPS system could become a selling point if the auto market in China picks up again later this year. It is still unclear whether and when group subsidiaries like Volvo will take over the upgrade. However, Geely is not the first brand with a supposed anti-virus filter.

Tesla has been advertising a Hepa filter for years and, with the usual immodesty, a “Bioweapon Defense Mode”. The air filter system was inspired by space travel. “We wanted to ensure that the system could capture and eliminate fine particles, bacteria, viruses, pollen and spores,” said Tesla. The filter system is said to be "several hundred times more efficient" than that of the competition.

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