What pollution causes (and we didn't even suspect)
It is a brilliant day, the sun is shining, the air is stirring the leaves of the trees and you feel like taking a deep breath. If you live in a big city know that with each inhalation you introduce into your lungs nitrogen dioxide (produced by traffic and industry), suspended particles (generated by traffic) and tropospheric ozone. There are three pollutants harmful to health that, according to Juan Bárcena, head of the Air Quality Area of Ecologists in Action, in Spain exceed the legal limit values set by the European Union. Also know that living on the outskirts of the city does not always offer guarantees, since it is precisely in that area where tropospheric ozone accumulates during the months with the most sunshine, a pollutant that, in the words of Juan Bárcena, “forms from of chemical reactions with other pollutants and the sun's rays, which is why it is higher when the weather is good”.
But the contamination is not perpetuated in the air, it spreads to the water, to the land and reaches the food. This is the case of persistent organic pollutants: DDT (a pesticide used against mosquitoes that transmit malaria), endosulfan (insecticide), hexachlorobenzene (pesticide) and polychlorinated biphenyls (PCBs), present in electrical equipment and old buildings. Remains have been found in remote areas: “These compounds, in addition to being transmitted through the food chain, also travel through the air: their volatility causes them to mix with hot air currents and settle in cold places. That is why traces of DDT have been found in penguins and polar bears, animals that inhabit places where this product has never been used”, explains Juan Pedro Arrebola, an expert in environmental pollution and a researcher at the Granada Biosanitary Research Institute.
None of the aforementioned pollutants is used in Spain, although they are still present in the environment because they have been designed to persist for years. Of course: the exposure doses are below the limits established by international regulatory bodies. However, Arrebola raises a question: "We do not know if continuous exposure translates into harmful effects in the long term, we must also take into account that we are exposed to several pollutants, not just one."
The World Health Organization (WHO) reveals a close link between exposure to environmental pollutants and the development of cardiovascular diseases, such as strokes and ischemic heart disease, lung disease and even cancer. In recent years, in addition, different investigations and studies have begun to point to pollution as a factor that contributes to the increase in other health problems, such as allergies. But there are others less known.
1. Contributes to obesity
The relationship between pollution and obesity has been studied for ten years: "It has been seen in in vitro tests that persistent organic compounds have the capacity to proliferate fat cells, in addition to being related to alterations in fat metabolism", says researcher Juan Pedro Arrebola. At the same time, fat appears to act as a magnet for these compounds. This follows from the study carried out by this specialist with 300 people, who were measured the concentration of pollutants in the body.
“We saw that the most obese had a higher concentration of pollutants. These tend to accumulate in fat, both from food and from people,” she says. Therefore, one of his advice is to take care of the diet and reduce the intake of products with fat, especially large oily fish (tuna, swordfish, etc.) that accumulate higher concentrations of fat and contaminants, because they usually have a longer life. "You have to moderate its consumption, especially in childhood and pregnancy, which are important times in development," he concludes.
2. Decreases performance in children
Researchers at the Center for Research in Environmental Epidemiology (CREAL), in Barcelona, have carried out a study with 2.897 children between seven and ten years old from 39 schools in Barcelona and San Cugat del Vallés (Barcelona) who were exposed to environmental pollution caused by the traffic.
For more than a year they evaluated whether exposure to air pollutants was associated with the cognitive development of minors through tests that assessed working memory and attention span. They also measured pollution due to traffic both in the schoolyard and inside the classroom. Surprisingly, children in the most polluted schools had less growth in cognitive development than those in the least polluted schools. They found, for example, that contamination by elemental carbon particles reduced the growth of working memory by 13%.
“The observed association was consistent in cognitive measurements, although it was more evident for working memory, a good indicator of learning achievement. Therefore, the reduction in cognitive development of children who attend schools with higher air pollution could lead to a disadvantage that should be taken into account in air quality control", explains Jordi Sunyer, researcher main of the study.
3. Generates skin problems
It seems logical to think that polluted air affects the quality of the skin (dryness, wrinkles) and there is work carried out by cosmetic brands that reflects this: a study carried out by Olay among more than 200 women in Beijing shows that those who live in Highly polluted districts have worse skin hydration than those in pollution-free areas. However, there are no studies in the scientific community on these effects. "It is difficult to quantify how pollution affects the skin because there are no internationally validated objective scales for measuring the qualities of the skin (luminosity, brightness, density...)", explains Dr. Cristina Eguren, attached to the Dermatology Service of the Hospital Infanta Leonor, in Madrid.
On the other hand, according to the dermatologist, a relationship between contamination and atopic dermatitis has been found by analyzing epidemiological data. “In the last 30 years, the incidence of this problem in industrialized countries has tripled and it is believed that the most influential factor is pollution. In non-industrialized countries they have a low rate of atopic dermatitis, but when immigrants from those countries come here they get our same incidence rate. Genetic changes cannot explain it because it is a short period of time for them to occur, ”she concludes.