Air pollution: the death that is breathed

• PUBLIC HEALTH. One in six deaths is due to contamination
• ENVIRONMENT: Air pollution causes 800,000 premature deaths each year in Europe

The perfect crime exists, it happens right in front of us and in broad daylight, with every inhalation of urban air. More than four million annual premature deaths worldwide are directly related to environmental pollution , according to the World Health Organization (WHO).

The killer floats in the air. It is so tiny that we could almost say it is invisible, but its size is precisely what makes it so dangerous. These are particles that arise from a mixture of solid and liquid substances, mainly from the combustion of cars or pollutants from industrial processes. Its diameter is only a quarter of a pollen grain and therefore it does not find any barrier to penetrate our airways and from them pass into the circulatory system.

And all this happens without us noticing, with every breath of air. Dr. María Neira, current Director of the Department of Public Health and Environment of the WHO, maintains that this is another peculiarity that makes the crime perfect: "The individual is not able to detect that there is a high level of pollution Obviously, people with existing pathologies, such as asthmatics, will detect it much earlier, just like those people who exercise a physical activity that requires significant respiratory capacity, but it is not a toxic substance that we see or touch. That is why we call it the invisible killer in WHO , because many times we are not aware as an individual and that does not protect us as it would be advisable. "

Your foray into our body leaves a mark, and if the exposure is prolonged that mark will be indelible . The respiratory and circulatory system are the most directly affected, and therefore most of the related diseases are located in them: air pollution is responsible for about half of deaths from Chronic Pulmonary Obstructive Disease (COPD) throughout the world, of almost 30% of deaths from lung cancer and a quarter of the pathologies and deaths from stroke or ischemic heart disease. A heart sick with pollution, as the famous 80's song said.

When does pollution start to be dangerous?

Dr. María Neira is blunt about it: "There is no level of safety, we should not breathe toxic substances; if there were, it would be rather zero." It refers to the levels established by the World Health Organization itself, based on the degree of concentration in the atmosphere of particles of 2.5 microns in diameter, and which aim to serve as reference points to achieve lowering the degree of contamination

According to these levels, and thanks to the collaboration of more than 4,000 cities around the world or that have monitored the quality of their air, more than half of the world's urban population lives in cities that exceed the recommended levels, and only the 18% of the urban population lives in cities whose air shows a lower concentration than the lowest threshold, 10 µg / m3. From it, the health effects begin to multiply.

It is not a true ranking, since it depends on the participation of the cities analyzed, so many of those who have been left out are likely to steal the top positions. Despite this, the list is useful when it comes to checking if, over time, those populations that have committed themselves to monitoring and fighting against their contamination achieve improvements, and it is also useful to check what type of elements are repeated among those cities with better or worse air quality.

The cities of the Eastern Mediterranean and African regions, followed by the countries of Southeast Asia, are the ones that refer the worst data in this list. Specifically, India holds almost all the latest positions with records that exceed 17 times the recommended level , as in the case of the cities of Kanpur and Faridabad. Not surprisingly in that country the annual mortality figure associated with pollution is close to two million. Both cities show a similar profile: they are overcrowded and are industrial centers. Kanpur is known for its leather industry, owns the largest tanneries in the world, and Faridabad is the center of all kinds of factories, from mechanical to textile and chemical.

At the opposite extreme there is an exception to any rule: the city of Sirnark, also known as "Nuh," the Kurdish form of "Noah," referring to the biblical figure that filled its ark with different creatures before the arrival of the universal flood. . Sirnark is currently the scene of another tragedy , but in this case much more earthly. 75% of its surface has been destroyed as a result of clashes between the Turkish special forces and the Kurds. In spite of everything, and according to the most recent records (2016), it is the city that shows the least polluted air, with a concentration that does not reach 1 µg / m3.

From the City of Noah we pass to Santa's home. Muonio, the next one on the list, is located in Lapland, and its landscape is tinged with snow from the first days of October until the beginning of spring. Its air barely exceeds 1 µg / m3 concentration, and its profile is already adapted to what is known, as will happen without exceptions in the rest of the less polluted cities. These are almost always smaller populations, with fewer inhabitants, and located in countries with high incomes.

Population vs money

What is more decisive for pollution? The overcrowding or the level of income? "For us, as Public Health," says María Neira, "what weighs a lot is the population, because that means that there is a higher number of inhabitants who are subject to levels

high pollution. "The director of the Department of Public Health and Environment of WHO also recognizes that the risk may decrease with economic capacity, as long as these resources are used to fight pollution , but it is not automatic. In addition, the fact that a city has a high per capita income on average does not prevent the existence of important poverty centers within them, very densified agglomerations with excess traffic ... and pollution.

The air knows no borders and that is why this is, or should be, a global struggle. The phenomenon known as Transboundary, serves precisely to explain the risk that a country may be contaminated by the neighbor. That happens for example in the case of South Korea, where they have their own pollution problem and at the same time are recipients of that of China. The same could happen within the same country, therefore, since the measures come from the cities themselves, they must all be involved at the same level.

The case of Spain is no exception in this whole scenario, we also present regions with less pollution, below that first threshold of 10 µg / m3, but as with other countries, they are almost always small or large populations rural. The best positioned of the cities is Santa Cruz de la Palma , closely followed by Benicàssim. And the one with the highest population with the lowest pollution is Cáceres, with a concentration of 5.66 µg / m3.

In the middle of the fight to remove, restore or modify central Madrid, what are the most effective measures? "Each city has to make its own assessment," recommends María Neira, "If we focus on the European model, the most effective measure is to better manage traffic within the city and avoid or reduce the presence of vehicles, especially diesel or older vehicles with filtering models that are even more polluting . " This measure must be accompanied by a good public transport system, which makes mobility possible within cities, and even better if these buses, for example, are electric. Dr. Neira also adds the need to improve energy management systems, inside and outside the home. Use energy reasonably and efficiently, without waste, and choosing renewable energy models. Our role model: the Scandinavian cities, "despite the cold weather, which we sometimes use as an excuse," adds the doctor.

Neira herself recognizes that these measures are sometimes unpopular at first, but she also argues that all cities that have advanced in that direction afterwards do not want to go back since they see the enormous benefits that these same measures facilitate. A summit of C40 mayors was held in Copenhagen in early October, and the results were satisfactory. "The mayors have pledged to reach the bosses," María Neira tells us, "they have understood what that represents, not only preventing people from dying in the cities, I don't know how they can carry that burden of mortality on their backs, but represents votes, citizens will appreciate it. "

Everything finally goes through greater awareness, and it seems that we are already on the road. "People have understood that this climate change is also the quality of the air and not only the glaciers or polar bears, they are also my lungs," explains María Neira, " When they ask me about Climate Change and I say that instead of call it CC let's call it PP, for Lung Lung , people will understand it better because it's something that touches you closely, it has to do with reducing life expectancy and destroying the quality of life. " And it does not exaggerate when describing the risks, even in the European Union, where particle concentrations meet in many cases the levels set in the guidelines, it is estimated that exposure to anthropogenic particles reduces the average life expectancy by 8.6 months

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