Subway PM2.5 Highest Value Exceeds World Health Standard Subway Experts Recommend Wearing Masks.

< p > do you know where the air quality is the worst in daily life and workplaces? Recently, the daily mail of London published the latest survey of King's College in London, found that in the indoor and outdoor environments, the air in the subway is the dirtiest, and the subway experts recommend wearing a href= "http://sjfzxm.com/news/index_s.asp" > masks < /a >.

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< p > < strong > subway PM2.5 value exceeds World Health Standard < /strong > /p >

Researchers at King's College in London chose 6 healthy volunteers to carry air detectors with P. They monitored the air quality at any time in a day.

Monitoring results showed that the air quality in the subway was the worst, the PM2.5 concentration per cubic meter reached 64 micrograms, followed by driving on the road, the value was 33, followed by walking to the shopping arcade and playground, the value was 31; the peak cycle was 26 on the road; the number of cars driving in the tunnel was 21; cooking in the kitchen was 19.

Relatively speaking, the air quality of garden and smokeless homes is the best, and the PM2.5 value is no more than 1.

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< p > according to the WHO's recommendation, in order to ensure human health, the PM2.5 value per cubic meter of air should not exceed 10 micrograms; the European standard is slightly lower than 25.

"But the highest value of PM2.5 in the subway has reached nearly 3 times that of the European standard, almost becoming the dirtiest place, and the pollution particulate matter is everywhere."

Frank Kelly, a professor of environmental health at King's College in London, said.

In 2011, Song Weimin, director of the Environmental Hygiene Department of Fudan University, and other experts also found that the air pollution level of underground stations exceeded the stations on the ground. Carbon dioxide as an important parameter to judge the pollution level of stations, the highest concentration exceeded 2 times.

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< p > < strong > Where does the pollution particle come from? < /strong > /p >

< p > Ben Barrett, a biomedical research center of King's College in London, believes that the < a href= "http://sjfzxm.com/news/index_s.asp" > pollution > /a > particulates may mainly come from dust particles produced by friction between wheels and tracks.

Hahn Carlson, a Swedish medical professor, also found that there are a lot of harmful particles in the subway air, such as coal, asphalt, iron and so on, which are mainly caused by the friction of the fuel and wheels which are not fully burning. In the air research of Stockholm metro,

They are more damaging than motor vehicle exhaust to health, killing more than 5000 people a year.

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Niu Wenyi, Professor of social medicine and health education, School of public health, Peking University, believes that underground, airtight and dense personnel are also important reasons for air pollution in many underground places, including the subway. P

When people breathe, they breathe out carbon dioxide and produce some fine particles. Inevitably, people will carry some dust. When they are crowded with each other, they will cause two dusts. Public places, though smoke-free, still have their own smokers.

These factors, coupled with poor underground ventilation, eventually led to a rise in PM2.5 in the subway.

Song Weimin study also found that fungal contamination is also an important factor causing all kinds of infections. All kinds of microbes are easily attached to the surface of particles and suspended in the air for a long time.

If the relative humidity of the subway is above 70% and the dust is too much, and the ventilation is bad and the sunlight is insufficient, the fungus can survive for a long time, which seriously affects people's health.

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< p > < strong > wearing masks < /strong > /p > when the subway stops.

< p > air pollution, especially the harm of micro polluted particulate matter to health, has been confirmed by more and more studies.

The British air pollution medical impact committee recently said that 29 thousand people died early every year due to air pollution in London, which is 10 times the number of deaths in traffic accidents.

Professor Kelly pointed out that PM2.5 is currently considered to be the biggest killer of health, even if it is a healthy population, it will cause chronic diseases in the body for a long time in the polluted environment.

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< p > "actually the environment in London is much better than ours.

Taking Beijing as an example, when the weather is good, the value of < a href= "http://sjfzxm.com/news/index_s.asp" > PM2.5 < /a can also reach about 100. If we measure it in the subway, we will not know how many times it is in London.

It also reminds us that the relevant departments should pay attention to the subway environment, such as changing the subway air-conditioning filter and filter regularly, monitoring and telling the PM2.5 value of the subway in real time, and strengthening the inspection and supervision by the health department.

After testing and analyzing the air quality of Tianjin subway station, Li Sha, an associate professor of Tianjin University of Technology, suggested that reducing the production of harmful substances is an effective measure to improve the air quality of the subway.

Smoking smoke, building materials volatile formaldehyde and so on are common pollution sources.

Therefore, the use of environmentally friendly decoration materials in subway smoking is conducive to ensuring the air quality in the subway station.

In addition, the air volume will directly affect the air quality in the subway.

She suggested that in the subway construction, the location of the sending and draining outlets should be reasonably arranged, for example, the draught should be near the source of harmful substances or the areas with high concentrations of harmful substances; the air outlets should be as close as possible to the customers, and be evenly distributed, reduce the eddy current and avoid the accumulation of harmful substances in the local area.

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< p > button reminds you that people who need frequent subway ride can choose to wear masks, nasal obstruction and so on to block harmful particles.

Passengers carrying diseases should wear masks voluntarily to prevent infection.

In order to avoid contamination of particles from wheel and rail friction, Song Weimin suggested that when the subway is in or out, it should be as far away from the platform as possible or wear a mask.

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