Sahara dust: bad for your health

The Saharan dust cloud or haze that currently hangs over Spanish skies is an oversized version of those constantly crossing the Atlantic, carrying particles that irritate the lungs, but also fertilize plant and ocean life.

The huge dust cloud has arrived in Spain, sweeping and staining the sky with a dense orange cloud. The air grew heavy with dust hour by hour. Readings from atmospheric stations marked higher numbers than ever before. Many of us have never seen anything like it.


Natural phenomenon.

This particular mist is both remarkable and totally ordinary. Each year, these types of storms sweep across the Sahara, carrying some 180 million tons of mineral-rich dust. Thousands of kilometers upwind, fine dust determines both the ecology of the places where it falls and the climate as a whole.

These fine particles irritate the lungs, cause respiratory problems, especially in people with chronic respiratory conditions, and can be very dangerous.

The dry desert expanses of North Africa are the largest and most constant sources of dust in the world. Sand dunes generally do not provide dust; only the strongest winds can lift such heavy particles. But the fine dust particles often accumulate in the hollows or flats of the desert landscape that once held water. Throughout the year, a strong wind blowing over the surface of these dust-rich places can blow tons of dust into the air.

Under the right conditions, usually between late spring and early fall, large amounts of dust are drawn into the “Saharan Air Layer”, hot, dry air that is often found above one kilometer from the surface of the Earth and which can be several kilometers away. thick.

In the summer, the dust leaves the mainland every few days. Once blown into the atmosphere by cooler air masses from the ocean, the dust can float for days or weeks, depending on the height and dryness of the air. Trade winds from east to west carry it across the Atlantic to the Caribbean and the United States in a matter of days. As the dust storm moves, they fall in a steady rain of particles.


Dust is harmful to health.

Saharan dust is mostly made up of tiny bits of minerals that were once rock. As you travel miles, the dust gets smaller and smaller, larger pieces are left behind.

Breathing fine particles is not good for the lungs.

Fine particle concentrates are harmful to human health. Respiratory diseases are one of the leading causes of death and disability worldwide. The dangers of exposure to poor air quality are well known, and scientists link prolonged periods of exposure to an increased risk of death from COVID-19.

These particles, with high concentrations of PM10 and PM2.5, in concentrations above those recommended, pose risks to human health.

The composition and the PM10 and PM2.5 particles themselves can produce harmful effects on the lungs.


Recommendations mist or airborne dust:

  • It is recommended not to exercise or exercise outdoors.
  • Try to leave the house as little as possible, only the necessary outings. People with respiratory illnesses should stay at home.
  • Monitor people with respiratory problems.
  • The use of FFP2 masks outdoors is recommended.
  • Stay hydrated.
  • Close and secure doors and windows.

In short, in the event of an intense Saharan episode, such as the one we are currently experiencing, it would be recommended to the most vulnerable people due to respiratory pathologies to reduce the time they spend outdoors.

Pathogenic bacteria.

In a 2016 study, a research team found that phytoplankton weren’t the only organisms that use magic desert dust. Bacteria, specifically 12 different species of pathogenic bacteria in the genus Vibrio, use these nutrients to create their own flowers.

Vibrio bacteria are quite abundant in the world’s oceans, but there are also freshwater species: you’ve probably heard of cholera, the disease caused by freshwater Vibrio cholerae, which infects millions of people around the world, especially in developing countries.

An outbreak of V. cholerae following the 2010 earthquake in Haiti killed an estimated 10,000 people, and in Yemen an ongoing cholera outbreak has infected over a million people and killed 2,000+ . Another Vibrio, the marine “flesh-eating” Vibrio vulnificus, is also quite lethal to humans. It enters through an abrasion or puncture, like a fish hook, and causes severe infection in immunocompromised people.

Marine species of Vibrio also play a role in many diseases of ocean organisms. Do you know that you are not supposed to eat seafood from certain places during the summer? This is because there is more Vibrio in the water when it is warmer, and filter-feeding shellfish accumulate Vibrio parahaemolyticus and Vibrio vulnificus in their flesh, which cause most shellfish-related illnesses and deaths. Other Vibrio species are known to be associated with diseased corals that are already dealing with many other environmental stressors. Diseases and mortality caused by Vibrio have even placed an economic burden on the fishing and shrimp farming industries.

Fertilizer rain.

Each dust storm influences biology and climate in places that are often thousands of miles from the source.

The dust that comes from the Sahara is an event that occurs every year.

The iron that gives Saharan dust its rich red color feeds phytoplankton.

It was long assumed that the world’s rainforests were the main source of oxygen in the atmosphere, but it is now more accepted that the production in the ocean acts as a second lung for the planet. Phytoplankton photosynthesis is responsible for half of the oxygen and also a significant uptake of carbon dioxide on the planet.

The mineral fragments that make up Saharan dust storms are often rich in iron and phosphorus; terrestrial plants and marine phytoplankton need these nutrients to grow.

When the dust breaks away from the traveling storm and lands on the sunny surface of the ocean, it fertilizes the photosynthetic organisms that live there, which are often starved of these elements. More than 70% of the iron available for ocean photosynthesis in the Atlantic comes from Saharan dust.

The powder does the same job for the Amazon. The rainforest is one of the most biologically productive places on earth, but the soil that anchors rainforest trees is notoriously low in some of the crucial elements for growth, especially phosphorus. Much of the land in the basin does not have enough phosphorus to support the abundance of life that grows there, and a key feature of rainforest habitat, rain washes away unused phosphorus almost as quickly as it appears.

fewer cyclones.

Many scientists believe that dust traveling high in the atmosphere plays another role in the Atlantic basin: it helps suppress the formation and strengthening of tropical cyclones.

Layers of dusty air are often very dry, and this is a death sentence for tropical storms, which feed on humid heat.

The layers of dust are usually carried by fast winds, so they can cross the ocean in a few days. A storm that develops into a powerful whirlwind can be tossed around by these winds, preventing it from developing.

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