The pollution due to photochemical smog due to NOx, it is visible by the human eye
The past Wednesday at midnight will be activated again the scenario 1 within the protocol’s anti-pollution of Madrid. It is the stage most mild, where is limited to 70 km/h the accesses to the capital (inside M-40) as well as the M-30. This measure attempts to alleviate the pollution by oxides of nitrogen (NOx).
The stage 1 is activated when there are two hours of level notice or notice of NOx. If two measuring stations of the air quality recorded values of 180-200 micrograms of NOx per cubic meter of air is reached to that level.
If not relieved by the weather or by the effective reduction of emissions due to the lower average speed -that, in reality, has an impact on very small – must go to scenario 2, where it will begin to produce limitations of traffic and parking.
The stage 2 is triggered when you reach 400 micrograms for three hours in a row, within the same area, if they report three measuring stations. That that the alert level. See our article on the different scenarios.
Now let’s put these figures in perspective
The annual limit value for the protection of human health is 40 µg/m3 annual NOx, and 200 µg/m3 not to be exceeded more than 18 times a year. Therefore, to limit the parking or the circulation in Madrid is done in situations of need, it is not a conspiracy of the city Council of Madrid, and become bitter to the drivers.
In 2016 has reached the stage 2, but has not reached a limit in the alternate circulation of vehicles (exceptions aside) because it has not reached a level so alarming. If the pollution by oxides of nitrogen is bad, let’s not talk already of the particles.
Map of the pollution in China is particulate matter PM2,5 – In green the areas with the same average level of contamination to Madrid in 2015. Yes, it could be worse
During 2015, the particles PM2,5 reached 40 micrograms/m3 in the station Schools Aguirre, and reached maxima above 25 μg/m3. The maximum supported by a european directive is 25 micrograms/m3 annual mean, and despite these peaks, the annual average remained below half of that value. What would happen over the long term, if Madrid were not to be taken measures? Let’s see what happens on the other side of the world.
If we go to China, we will understand the dimension of the problem in a different way. In Beijing, during 2015, the average levels (not maximum) of fine particles were 83,2 micrograms/m3, that is to say, seven times more than Madrid. Shenzhen tripled the level of Madrid and Shanghai it quadrupled. There are many towns to mention, but these are some of the most well-known.
In this country has reached a record of pollution of 1,000 µg/m3 in Shijiazhuang. According to the WHO, prolonged exposure of more than 10 micrograms/m3 are sufficient to suffer from cardiopulmonary disease, as well as lung cancer. Therefore, Madrid also has a serious problem of contamination by fine particles, the average value exceeds the 10 micrograms/m3.
Traffic in Madrid – Photo: José Antonio Morcillo Valenciano (Flickr) CC BY
Fortunately, Madrid does not have as much heavy industry as many chinese cities, nor have as much population, nor is it a use as intensive as coal. The main problem is the traffic. China has adopted Euro 4 recently, in Madrid governed in Euro 6. If the chinese have the same proportion of diesel passenger cars that Madrid probably would have died, drowned.
measures to limit pollution, such as preventing the parking or the circulation, are certainly uncomfortable, but have been planned as a last resource. Madrid very much depends on the weather to keep the air clean, that if there is no exodus holiday that will alleviate the impact of traffic. Little is done to pursue those who suppress particulate filter (customers, not workshops, they are more guarded), as inimical to the public health.
The main responsible of the pollution by oxides of nitrogen are diesels, and that more fine particles emitted are the diesel and some petrol turbo charged with direct injection of the latest generation. The day formally accused the manufacturers to produce thousands of deaths each year in Europe by the pollution of its cars, we will be faced with a scandal-industrial of biblical proportions.