what are the health risks?

The dust transported from the Sahara, which has been responsible for the orange color of the sky since Tuesday, contains elements that can be toxic, and fine particles, which can therefore enter the body and cause lung and cardiovascular damage.

A thin layer of sand from the Sahara fell over much of Spain from Monday to Tuesday, before rising towards France. The phenomenon, which should last and disappear until Thursday, has a strong impact on air quality in Spain, where stations in Madrid measured “extremely unfavorable” air quality Tuesday.

Currently there does not appear to be an impact on the particulate matter level in France, but the spread of this dust is being closely monitored as it can have an impact on both air pollution and health.

Fine particles that can enter the body

Particles from sand and dust storms include particulate matter, which – such as during pollution peaks caused by car traffic, for example – can infiltrate the lungs and cause certain damage.

“When this desert dust is found in so-called coarse particles (PM10) (ie a diameter of less than 10 micrometers), they enter the body. Their amount can cause health effects and seriously affect health,” underlines ATMO Nouvelle Aquitaine, (air control agency) .

“Sirocco facilitates the transmission of pathogens through the respiratory tract”, also writes on Twitter the medical biologist Claude-Alexandre Gustave Tuesday. “Inhaled sand particles can serve as vehicles for bacteria, pathogenic viruses (…) They also promote inflammation of the lower respiratory tract, which can complicate respiratory infections or chronic pneumopathies.”

A sometimes toxic composition of this substance

Aside from the dust itself, what it wears can be dangerous. So, to the sand particles can be added “particles resulting from human activities, such as residential heating, car traffic or even agriculture,” notes ATMO Nouvelle-Aquitaine.

These winds can also transport pollen, cell fragments, molds and fungi, and “some of these microorganisms may be opportunistic pathogens for humans” wrote the INVS (Institut de Veille Sanitaire) in a report of 2017 on desert sandstorms. Some fungi found in these shipments are known to cause “allergic reactions, lung infections or skin infections in humans.”

Under certain conditions, chemical reactions can occur between the mineral elements in sandstorms and certain components present in the atmosphere.

He notes that “thus on the island of Majorca it was possible to measure peaks of sulfates during sandstorm periods as a result of the chemical reaction between the calcium and magnesium carbonates in the dust from Africa and sulfuric acid compounds in the local atmosphere”.

However, it is important to specify that currently “air pollutants are in a minority from phenomena of natural origin (sand winds from the Sahara, soil erosion, volcanic eruptions, etc.) and in the majority of human activities”, explains the Ministry of Health

Decreased Respiratory Capacity and Cardiovascular Effects

All of these elements can lead to multiple health consequences for people exposed during the peaks. “The health effects of aerosols depend on their composition in chemical and microbiological elements, and also on the size of the particles that make up them,” explains the INVS.

“Large PM10 particles are more likely to be deposited in the bronchi and thus impair breathing capacities (asthma, chronic obstructive pulmonary disease, pneumonia and other respiratory infections), the report explains. “In contrast, fine particles (PM 2.5) are more likely to reach the alveoli, cause systemic inflammation and lead to cardiovascular effects.”

“There is a close and quantitative association between exposure to high concentrations of particulate matter and particulate matter (PM10 and PM2.5) and increased mortality and morbidity, both daily and in the long term,” the World Health Organization also writes.

Claude-Alexandre Gustave advises to continue wearing the mask during these periods of air pollution. The Department of Health also advises “prefer shorter trips and those that require the least effort” and in the case of respiratory or heart problems, “seek the advice of a health professional”, especially if you have a fragile heart or have a fragile lung.

Salome Vincenton BFMTV journalist