MADRID – A large amount of Saharan sand now in the air over much of Europe could have health consequences. A recent study discovers the inflammatory mechanism of the upper respiratory tract that may be the prelude to angina pectoris or pulmonary fibrosis.
According to the National Air Quality Index (ICA), “extremely unfavourable” air quality levels due to PM10 particulate matter have been recorded in provinces such as Madrid, Almería, Murcia, Ávila, or Burgos. To give us an idea, the authorities warn that the daily average should not exceed 40 µg/m3 of these particles. Some parts of the country, such as Murcia, report levels exceeding 300 µg/m3 due to the cloud of Sahara sand.
Click here to check the air quality in Spain
The aforementioned study, conducted in the Canary Islands, sheds some light on the health implications of breathing Sahara sand. The Canary Islands are regularly ravaged by clouds full of Sahara dust, also known as calima. The fact that a large cloud of dust from the largest desert in the world floats over Europe these days is a bit more exceptional.
Inflammatory response
The Sahara cloud contains tiny particles that turn the sky red. These particles can irritate the eyes and carry small traces of pollutants from Africa. Inhalation of this dust in suspension* triggers an inflammatory reaction in the upper respiratory tract. Scientists believe this could be the first step towards the next development of cardiovascular and respiratory diseases.
Until now, science has linked Sahara sand episodes to an increase in premature deaths of between 0.55 and 0.65%. Death due to pathologies such as heart disease or lung disease. Only it was still impossible to know how the body reacted to exposure to inhaling desert dust.
First biochemical analysis shows the inflammatory response
For the first time, a group of researchers from the Canary Islands has conducted a biochemical analysis. Patients were admitted to the University Hospital of the Canary Islands after episodes of Saharan dust – also known as calima – that occurred between June 29 and November 22, 2017.
The researchers were able to verify that the portion of the airways leading from the pharynx to the bronchi (the portion in front of the lungs) ignites upon contact with these particles.
Biomarkers of inflammatory processes
In the scientific article ‘Impact of Saharan dust exposure on airway inflammation in patients with ischemic heart disease’, scientists discovered that the concentrations of exactly two biomarkers of inflammatory processes in our body in the airways of the patients increase after inhaling the Saharan dust.
Research among patients on Tenerife
Researchers conducted this new study in Tenerife among patients attending the HUC cardiology outpatient clinic. 270 people voluntarily participated in the research. However, 232 were removed from the sample. They were removed because they smoked, suffered from chronic obstructive pulmonary disease, asthma, lung abnormalities, acute bronchial or lung disease.
Subsequently, at this screening, the sample consisted only of patients who had visited the hospital’s cardiology department for stable chronic coronary ischemic heart disease**. Consequently, they prevented with this screening”a false signal”.
The discovered inflammation of the inflammatory pathways also has to do with the infiltration and accumulation of immune cells in the tissue of the airways as a result of exposure to pathogens inhaled by the calima.
‘Irreversible changes and loss of lung function’
The inflammatory process, in turn, contributes to the thickening of the walls of the respiratory tract. Which, in the long term, could “lead to irreversible changes and loss of lung function,” the study’s signatories point out.
A possible consequence of inhaling desert dust
“Until now, research derived the possible effects from statistical analyses,” explains one of the researchers. The article confirms “an inflammatory process” that may be the prelude to the onset of “cardiovascular and respiratory diseases” described in other articles. Therefore, inhaling desert dust increases the risk of a long-term cardiovascular event, such as angina pectoris, or a respiratory event, such as pulmonary fibrosis.
More damage than originally expected
The World Health Organisation (WHO) considers concentrations of particulate matter above 50 micrograms per cubic metre to be harmful. And calima episodes should also be included in this consideration. Scientific studies of recent years have shown that they do more damage to public health than originally expected.
The Sahara also pollutes
“Until now, we focused on the health effects caused by pollutants emitted by traffic, industry, and combustion,” explains Sergio Rodríguez, a researcher at the Superior Council of Scientific Research (CSIC). However, no one paid any attention to the floating desert dust.
Chronic Obstructive Pulmonary Disease
However, inhaling these dust particles can lead not only to inflammation of the airways but also to damage to the mucous membrane that protects these airways. This makes individuals more susceptible to other potentially harmful substances. A consequence that, in the long term and with continuous exposure to this pollutant, can lead to the development of chronic obstructive pulmonary disease (COPD).
Unanswered questions
What is still unknown is how intensely an episode of dust can affect the body. Especially if the concentrations of dust are16 times higher than those recommended by the WHO. In any case, this work is likely to continue because “we still don’t know what happens in the bronchioles and the alveoli,” as Rodríguez points out.
The Canary Islands have therefore become the “ideal” laboratory for studying the health effects of desert dust. The researchers conclude that they can extrapolate their results to large areas of the planet. These are for example northern Africa, the subtropical and tropical North Atlantic, central and inland Asia.
How can you protect yourself from the Sahara desert dust?
Take precautions to avoid the effects of these potentially harmful particles on our body as much as possible.
- Wear a mask when you go outside. An FFP2 mask protects the best
- Do not go outside to exercise or take a walk
- The population groups most vulnerable to this phenomenon should try to spend as little time outside as possible. Think of the elderly, pregnant women, children, or patients with chronic respiratory diseases, such as asthma or COPD
- Wash the eyes with plenty of water in case of irritation
- Wear glasses
- Cover water sources, such as wells, to prevent contamination
- Close the windows of the house
- Drink plenty of water
*In physical chemistry, a suspension is a mixture of two substances. One of which is mixed with the other in very small particles and the mixture does not separate quickly. (Wikipedia)
**Narrowing of the coronary arteries (atherosclerosis) can cause heart problems. This results in reduced blood flow and oxygen supply (ischemia) to the heart muscle.
