Last time, according to the information collected by the OBD online emission terminal of the National Sixth National Congress, we made a careful understanding of the impact of vehicle exhaust emission on the environment, and also made a certain analysis on the emission and generation mechanism of vehicle pollutants. Today, I mainly want to talk about the impact of motor vehicle exhaust pollutants on human health.

Maybe everyone knows something more or less. It's definitely a good thing to have this foundation, at least it won't be ignorant. At present, vehicle exhaust pollution has become one of the main reasons for accelerating the deterioration of urban air. With the change of "epidemic situation" in 2121 and the requirement of returning to work, there has been a clear contrast.

Why do you say that? Let me give an example of real life that is very easy to understand: I returned to Shenzhen on February 9th, and my company resumed work on February 1th. In the middle days, there were several torrential rains in Shenzhen one after another, and I drove to work. Because there were few vehicles and the roads were clear, the appearance of the car body was basically the same as that of the washed car. At this time, most enterprises in Shenzhen did not return to work, which was probably less than 31%. On February 8th or so, the state required enterprises to resume work, followed by an increase in the number of cars on the street. At 11 o'clock in the evening, the sound of traffic on the main street could be heard. In these two days, a heavy layer of ash was deposited on the glass and ceiling of the car (there was no infrastructure around). This detail may not be noticed by everyone. I check the car body and tire condition before driving every day (the temperature is low, the car that doesn't run often is afraid of abnormal tire pressure).

It can be seen that urban pollution is closely related to the movement of motor vehicles, and many things that are invisible need to be solved by technical means. Motor vehicles cause obvious air pollution to the urban environment, especially to the areas near roads. If your "facade room" faces the roads, it is very likely that the ecological environment and human health have been threatened by the address, especially children, the elderly, pregnant women and people with heart disease and lung disease, who are more vulnerable.

We are most concerned about four kinds of harmful gases contained in vehicle exhaust pollutants.

carbon monoxide

carbon monoxide (CO) is a COlorless, odorless and odorless gas. It is generally believed that co shows toxic effect because it is inhaled into human body. Because its affinity with hemoglobin (Hb) which plays an oxygen transmission role in blood is 211-311 times greater than that of oxygen, it can travel with hemoglobin to form carboxyhemoglobin (CO-Hb), which greatly reduces the oxygen transmission ability of blood, resulting in. If you can get in touch with this suffocation state in time, the symptoms will disappear. If the concentration is too high or it is not relieved in time, it will be very dangerous. The combination of carbon monoxide and hemoglobin will make cardiovascular work difficult, leading to exhaustion and inability to "do work".

However, under the research of scientific and technological tests, it is found that gas piping workers have symptoms of memory decline, which shows that the problem of chronic poisoning exists. Because CO stays in the bottom of the atmosphere for a long time, we should limit the CO concentration in the inspiratory within 24 hours to below 5PPM. Since its accumulated concentration often exceeds the allowable value, our gas workers must pay attention to its harmfulness. The effects of different concentrations of CO on human health are as follows:

Table 1: Effects of different concentrations of CO on human health

CO concentration /PPM

Effects

5-11

Effects on respiratory patients

31

People stay for 8 hours, and their vision and nervous system are impaired

41

People stay for 8 hours. Headache

511

contact for 2 hours, severe heartache, dizziness and collapse

3,111

31 minutes, and death

Hydrocarbons

Hydrocarbons (HC) are generally called hydrocarbons, and there are many kinds of pollutants emitted by motor vehicles, including unburned and incompletely burned fuel, lubricating oil and cracking products and parts.

the concentration of hydrocarbons in motor vehicles is greatly influenced by the working conditions and realization conditions of the vehicles, ranging from several tens of PPM to more than 1 million PPM. Saturated hydrocarbons are generally harmless, methane gas is non-toxic, and ethylene, propylene and acetylene are mainly harmful to plants, so every time we watch a documentary, we see that air pollution will affect the growth of plants, and human beings are always suicidal.

However, unsaturated hydrocarbons are very harmful. Benzene is a colorless gas that smells like gasoline. It is estimated that children who say that gasoline smells good still exist. The smell emitted by motor vehicle exhaust can cause symptoms such as loss of appetite, weight loss, tiredness, dizziness, headache, vomiting, insomnia, mucosal bleeding, etc., and can also cause blood changes, decrease of red blood cells, anemia and leukemia. Formaldehyde, acrolein and other aldehyde gases will also have a strong stimulating effect on eyes, respiratory tract and skin. If the concentration exceeds a certain level, it will cause nausea, decrease of red blood globules, anemia and acute poisoning. This often happens in paint shops and non-standard home decoration. People obviously feel that it is not right to go in. At this time, you will really come out, especially pregnant women who have newly bought a house for decoration. The most harmful to human beings are polycyclic aromatic hydrocarbons, especially benzopyrene (barbecue, oil fume, tail gas, fried vegetables, fried), which is a strong carcinogen and is not explained. On the way back and forth, stay away from the lighted tail, fast-forward and fast-exit at the high-speed service station (some people don't turn off the engine when parking), and pedestrians should also go quickly when passing the lighted vehicles and traffic lights, so as to stay away from injuries and protect their families. This is what we should advocate.

nitrogen oxides

nitrogen oxides (NOx) are the products of the combination of the remaining oxygen and nitridation during the high-temperature combustion of fuel, and the main components are NO (nitric oxide), NO2 (nitrogen dioxide), N2O3 (nitrogen trioxide), N2O5 (nitrogen pentoxide). We may not remember that much, in fact, we don't need to remember the rest. From the perspective of air pollution and emission, as long as we look at nitric oxide and nitrogen dioxide, the rest is ignored, which is really negligible.

NO is a colorless and odorless gas, and its binding ability with red pigment in blood is stronger than that of CO. High concentration of NO can cause paralysis and spasm of central nervous system. NO2 is a brown gas with a special pungent odor, and it is one of the malodorous substances in motor vehicle exhaust. NO2 is toxic, insoluble in water, and less irritating to eyes and respiratory tract, but it is not easy to be detected when inhaled into respiratory tract in large quantities. Nitrite and nitric acid will be formed after entering alveoli, which will stimulate lung tissue, cause pulmonary edema and cause obstructive fibrobronchitis. It may be a bit vague to say this. NO2 causes climate change, acid rain and smog. If there is acid rain, it must be strictly investigated and dealt with.

table 2: effects of different concentrations of NOx on human beings and organisms

NOx concentration /PPM

effects

1.5

For 3-12 months in a row, emphysema appeared in the parts suffering from bronchitis

1.1

When the smell was smelled

2.5

for more than 7 hours, the plant leaves turned white

. Stimulation of the nose for

81

3-5 minutes causes chest pain for

111-151

31-61 minutes, and death due to pulmonary edema for

211

rapid death

particulate matter

The impact of particulate matter (PM) on human health mainly depends on the particle size and particle size. There is a positive correlation between the number of people who go to the hospital for upper respiratory tract infection, heart disease, tracheitis, pneumonia, emphysema and asthma and the concentration of atmospheric particulate matter, which is more in the north than in the south, so this is not explained. Coal mines and thermal power plants often inhale particles of 1.11-1.1um, 51% of which will be deposited in the lungs and cause pneumoconiosis. If you must go out, wear a mask and drive.

the air pollution caused by motor vehicle exhaust is often not caused by one substance, but by the comprehensive effect of many pollutants. After it is discharged, it forms a primary pollution, and then changes again through physical and chemical actions, and reacts with other substances in the surrounding environment for the second time. Some are good, such as nitrogen being absorbed by plants, and some will cause secondary pollution, which can also be called secondary pollution, and the harm degree is more serious than primary pollution.

NOx and HC discharged into the atmosphere by motor vehicles will produce an irritating light blue smoke under the action of solar ultraviolet rays, which is called photochemical smog. This smog contains ozone (O3), aldehydes, nitrates and other compounds, with ozone accounting for 85%. Solar radiation intensity is an important condition for photochemical smog. You saw the blue smoke on the bottom of the car, that's why.

I have learned from middle school chemistry that ozone is a very strong oxidant with a unique odor. What are the effects of ozone with different concentrations on human health? I also made a table:

Table 3: Effects of different concentrations of O3 on human health

O3 concentration /PPM

Effects

1.12

Began to smell bad smell

1.2

Smelled strong odor for 1 hour

1.2-1.5

Vision loss for 3-6 hours

. Paralysis causes pulmonary edema

51

31 minutes to death

In Los Angeles, USA, in 1955, there was a photochemical smog incident caused by motor vehicle exhaust. In one month, 411 people over 65 died. This kind of pollution is also very serious in Tokyo, Japan. In the pollution incident in 1971, the concentration of photochemical smog was 11 times higher than usual, causing 21,111 people to suffer from pinkeye and throat diseases, which increased to 41,111 in 1971. China's first tier cities, such as Beijing and Shanghai, is also threatened by photochemical smog. Some scientific and comprehensive measures must be taken to prevent and reduce the harm caused by photochemical smog. After years of efforts, it has been effectively controlled, and the smog phenomenon is still serious. The air quality in many areas is still not up to standard, and motor vehicles have not been effectively supervised. The supervision of motor vehicle exhaust emissions has only been put on the agenda in recent three years.

As a result, Beijing has issued a policy. Since July 1, 2119, the city's heavy-duty gas vehicles, public transport and sanitation heavy-duty diesel vehicles have implemented the national six B emission standards; From October 1, 2121, light gasoline vehicles and heavy diesel vehicles will implement the national six B emission standards. Subsequently, Shanghai introduced the standards of Shanghai, Hangzhou introduced the standards of Hangzhou, and Zhengzhou introduced the standards of Zhengzhou. Although local policies were adapted to local conditions, strict supervision was achieved, and there were differences, but we also saw the determination of local governments to "fight".

no matter what kind of standards you introduce, the purpose is to start from the source, from the doll. Compared with the national five standards, the limit of the national six B standard for light vehicles is tightened by 41% to 51%; Increased the actual road driving emission control requirements; The evaporative emission control requirements are stricter, and the emission limit is reduced by 65%. It is necessary to install an on-board refueling oil and gas recovery system (OR VR) to control the oil and gas emission during refueling. At the same time, the requirement of emission warranty period is increased, the limit values of carbon monoxide (CO) and hydrocarbon (HC) in low temperature emission test are tightened by 1/3, and strict control requirements of on-board diagnostic system (OBD) are introduced.

It's just that Speedy is engaged in this on-board diagnosis system. It can be regarded as the spring breeze of the policy in the OBD environmental emission monitoring of the National Sixth National Congress. In fact, we have studied automobile pollution emissions more deeply than any OBD enterprise. The predecessor of National Sixth was DB11-1475 (Beijing local standard). As an expert team of commercial vehicle bus, Suride participated in and formulated this standard for OBD off-line monitoring and emission of heavy fuel trucks with the State Bureau of Metrology, Environmental Ecology, Tsinghua University and China Automobile Center. Based on the policy spring breeze, we will build an on-line emission monitoring vehicle wireless terminal. This on-line emission monitoring vehicle wireless terminal will help the national and local eco-environmental departments to report the vehicle emission data to different environmental protection data centers and platforms of the National Eco-environmental Center. Whoever exceeds the standard will be inspected and will be responsible. If the vehicle exceeds the standard, the vehicle factory will be fined. If the individual exceeds the standard, go to overhaul your vehicle emission reduction sensor, fill and discharge, and check the aging and maintenance of the three-way catalyst and oxygen sensor of the vehicle. Otherwise, the new car will not be licensed at all (Hangzhou implementation).

The online monitoring system of OBD emissions of the National Sixth National Congress will help the country to strictly control the energy consumption, pollutant emission and control of motor vehicles in the ecological environment of vehicle emissions, greatly reduce the harm of vehicle emissions to health, and restore a healthy ecology for human beings and a clear water and blue sky for the world.

This article comes from the author of Chejia, car home, and does not represent car home's standpoint.