This article is from the WeChat public account: Earth Knowledge Agency (ID: diqiuzhishiju) , author: Han Xing cold night, drawing: Sun green, proofreading: cat Stewart, editor: Yakult
In mid-February, many people ended their longest spring break and started working. Rail transportation is the main force of the Spring Festival every year, and this year’s special circumstances are no exception.
However, some worrying voices are emerging: Will the small, closed train compartments become a breeding ground for viruses? Will it further aggravate the cross-infection of the virus? Today’s article will take you to discuss whether the train will be infected by the disease?
It’s really small and tightly closed (Picture @ 杔 格)
There is a lot of sickness and no food, and I have n’t returned to my hometown for thousands of miles
When talking about the epidemic of train-borne diseases, many people first think of a famous disaster movie, which was released in 1976 in the Cassandra Bridge. The film tells the story of fugitive terrorists spreading the deadly Yersinia pestis on the train, the International Police Department intends to destroy the train, and the passengers on the train unite to break through the blockade.
It ’s really awaiting. You can find this video (picture from: “Cassandra Bridge”)
In the film, the narrow and closed train compartment allows the rapid spread of plague bacillus, which almost creates a huge biochemical disaster. This is not alarmist, especially the old green leather trains without air-conditioning ventilation system. (Currently the national railways include air-conditioned trains starting with Z, T, and K. They have been brushed into green car bodies one after another, so trains without air conditioning systems are referred to as “old green leather trains”) , which can easily cause relatively closed infection spaces for respiratory diseases. The prevention and control of tuberculosis in the early years is an important task that the railway epidemic prevention department has long adhered to.
Old green skin (in fact, it is often full of people) (Picture @ 金 涵涵 / 图 虫 创意)
For passengers, the capacity is up to 118 people in a regular-speed hard-seat carriage. The crowd is not only intensive, but also a large number of mobile people getting on and off the bus. Coupled with activities in the car such as toilets and drinking water, the number of people exposed is indeed certain Exposure risk.
For long-distance train attendants who receive long-haul passengers for long periods of time, the exposure time is even higher. In this year’s new coronavirus pneumonia epidemic, many crew members have been diagnosed with the new coronavirus infection, which even caused the entire class to be isolated and trains stopped.
Not only flight attendants, but staff outside the establishment are also vulnerable to virus infection in such a small space (picture @ 杔 格)
In the past trains, there was another kind of insects that acted as an intermediary for disease transmission. This was fleas.
(picture from: shutter @ Jiri Prochazka)
Even today, in the sleeper compartments of trains, passengers are bitten by fleas. The appearance of fleas is not necessarily a health issue in train compartments. In long-distance trains, if it is not from the start to the end, this berth will be sold to many different passengers. The bedding for this berth is (sheets, sheets and pillowcases) The replacement can only be done at the terminal. There is no space on the train to store so many beddings to achieve “one passenger and one replacement”, and the seat covers of hard seats, chairs, etc.
The sleeping berth in the train is not the only bed you have ever slept in (picture @ 图 虫 · 创意)
So no matter how clean the train is cleaned up, fleas will still be carried into the carriage by passengers. Flea, as a vector of pathogens, can transmit a variety of important infectious diseases, including ascariasis, plague, hemorrhagic fever with renal syndrome, endemic typhus, and Bartonella disease.
Clinical manifestations of flea disease
Washrooms, urinals and trash cans, which often appear dirty on older trains, are also a high-risk area. However, in terms of the current sanitation of China’s railway passenger trains, the risk of disease transmission in toilets and urinals on trains will not be higher than those in other public places.
The spring rain breaks the bridge, and the boat propels out the willow yin
Facing the risks of disease transmission mentioned above, China ’s railways, which are realizing “leap-forward” development, are not only seeking speed, but also “inside-to-out” safety for passengers. In the face of the new coronavirus epidemic, IWe don’t have to panic too much, because in the past 20 years, the “software and hardware” of disease prevention on our trains have become more advanced.
The first is the continuous improvement of train ventilation conditions.
Ventilation at the window opening and the air intake at the junction of the carriage are the air circulation methods used by the traditional non-air-conditioned old green leather trains. However, with the rapid increase of several speeds on the Chinese railway, window opening ventilation cannot meet the requirements of airtightness of trains at high speeds. At the same time, when the train is running at a high speed, if the window is opened, dangerous situations such as falling of passengers or the impact of the tunnel airflow inside the car are likely to occur.
When there are too many people, it would be too uncomfortable to open the window without ventilation (picture from: solofugue / Tuworm Creative)
Instead of the old green leather train, the new air-conditioned car body uses air conditioning to supply air to the carriage and the air at the junction of the carriage to achieve air circulation.
Although the car body is closed, the air-conditioning air supply system enables air circulation in the car. At present, national air-speed trains, direct trains with Z prefix, express trains beginning with T, and express trains beginning with K all use new air-conditioned hulls, only because the national railways with speeds below 200 km / h require green paint. So now air-conditioned trains have also become “green cars”.
(picture from: a circle / worm creative)
For the average passenger, sitting in a compartment with a powerful air-conditioning system, the risk of contracting respiratory diseases is much lower than in old green leather cars. As high-speed trains are put into operation, its more powerful air conditioning and fresh air system brings you a safer, healthier and more comfortable riding environment.
As the high-speed railway EMUs are put into operation, many people are worried that the high-speed railway will pursue stricter air-tightness standards in order to drive at high speeds. Is the air inside the car even worse with weak air conditioning?
It seems more closed, but it may not be the case (Picture @ 图 虫 · 创意)
Actually not. Take the CRH3-380, CRH1 and CRH5 EMUs as an example. In order to increase the diversion space inside a high-speed air-conditioning unit, the size of the compressor is reduced during design and production, and environmentally friendly R407C refrigerant. At the same time, the vehicle body ventilation system is designed with natural ventilation and forced ventilation systems, thereby achieving more efficient ventilation.
CRH5 (Picture @harmony 3C-0869 / Picture Worm Creative)
However, whether it is a high-speed rail or a general-speed air-conditioned train, once the train is stopped due to a line failure, the air-conditioning of the train will lose its power. Therefore, the summer train will stop due to the breakdown and cause sultry carriages and passenger sweat. But this is not an air-conditioning exhaust system