It is a proven fact that pollution in cities increases the chances of suffering from allergies, even in the non-predisposed population. It may seem paradoxical but it is very common that, in large cities, where pollen concentrations would be expected to be lower than in the countryside, allergies skyrocket. Why does this happen?
It seems that, due to pollution and climate change, pollens express a higher content of allergenic proteins. For example, a work published in 2004 in the journal Allergy concluded that, in areas with high levels of contamination, Arizona cypress trees ( Cupressus arizonica ) express higher amounts of Cup a 3, an allergen present in the pollen of these plants. . A similar study published by Spanish researchers in 2002 and focused on grass pollen, one of the families of plants whose pollen produces more allergies, also revealed that pollution triggered its allergenic activity through the expression of the compound Lol p 5 .
On the other hand, according to a review on the subject published in 2007 in the Journal of Investigational Allergology and Clinical Immunology , diesel emission particles can cause, in contact with pollen grains , the shelling of the plant, facilitating the arrival of these particles to the respiratory tract.
More allergies in a climate change scenario
Climate change also affects the pollen calendar of plants, since it advances or lengthens the pollination period. Furthermore, in the presence of high concentrations and temperatures of CO2, plants increase their pollen production. Climate change can also lead to the extinction of species and the consolidation of non-native species, with the consequent risk of allergic sensitization in the exposed human population.
It is a kind of vicious circle, since rising temperatures and the absence of rain are also responsible for the levels of pollution to skyrocket in large cities. “PM10 particles (between 2.5 and 10 microns in diameter) and, especially, the finer particles (those with less than 2.5 microns) that are produced by combustion engines accumulate in the absence of wind and rains, amplifying allergic responses to pollen. So not only do we have advanced and anomalous pollen production, but its effects on health are more pronounced, especially in urban areas ”, explained Fernando Valladares, researcher in the Department of Biogeography and Global Change of the National Museum of Natural Sciences (MNCN-CSIC), in an article published in The Conversation on early spring and climate change.
What will allergy season be like?
According to the Spanish Society of Allergology and Clinical Immunology (SEAIC), in Spain there are more than eight million allergic people. This organization predicts that in 2019, the amount of pollen grains in the air will be between moderate and intense, especially in the south of the peninsula.
To prevent episodes, it is advisable to know what type of pollens we are allergic to and at what times of the year we can be most affected. The use of sunglasses when we are on the street, or avoiding going out first thing in the morning or at the last minute , when pollen levels are higher, are some simple measures to make spring more bearable if you are allergic.
Experts also recommend rolling up the windows when we are in the car, closing windows at home and cleaning the filters if we have air conditioning. Another simple measure is to change our clothes when we come from the street , thus avoiding contact with the pollen that may have been attached.
According to SEAIC experts, foods with vitamins E such as nuts and vegetables help people with allergies to improve the respiratory symptoms caused by this seasonal illness. And, if our eyes itch a lot, we can wash with serum or chamomile.
