Small particles can lead to serious respiratory issues
Johannes Saers, general practitioner at Baggängens health centre in Karlskoga, Sweden and recent PhD graduate at Örebro University.
When sandstorms swept across Sudan, researcher Johannes Saers observed something that raised both concern and curiosity. Swedish soldiers who had never previously been in a desert environment suddenly started experiencing various respiratory problems such as asthma and the early stages of COPD. “Studies show that small airborne particles can contribute to lung disease,” he says.
”Before I started medical school, I served as a UN officer in Sudan. While there, I noticed that when the sandstorm season began, several colleagues who came from non-desert countries developed unusual pneumonia and new-onset asthma,” says Johannes Saers, general practitioner at Baggängens Health Centre in Karlskoga, Sweden, and recent PhD graduate at Örebro University.
When he asked fellow doctors both locally and back home in Sweden about a possible connection, it was considered unknown and nearly unthinkable.
“As the years went by, Americans began to notice the same phenomenon in their soldiers, and that's when I started investigating small particles. What made it particularly exciting was that it was mostly uncharted territory in research terms.
This marked the start of a research journey – from desert sand to ironworks, wood pellet plants, and pulp mills – examining how traffic and occupational exposure contribute to respiratory problems. This led to the doctoral thesis Dust Exposure as a Risk Factor for Respiratory Disease.
Blood rain sweeps across Sweden as sandstorms travel thousands of kilometres
Sandstorms can affect life as far north as Sweden when sand is blown high into the atmosphere and falls as rain, known as blood rain.
“It’s sand and dust from the Sahara. When it rains, you can sometimes notice the ground being slightly reddish due to the particles. This is oxidised iron after it reacts with water. But it’s rarely concentrated enough in our latitudes to be harmful,” he explains.
Protective equipment and air filtration
“In all my studies, there would appear to be a link between the number of particles, the duration of exposure, and the severity of symptoms that follow. This applies to Swedish military personnel on overseas deployment, workers in wood pellet plants, pulp mills, and foundries, and those exposed to both traffic-related and occupational air pollution,” says Johannes Saers.
In workplaces where the air may contain harmful particles, it is essential that staff wear appropriate protective equipment and that ventilation systems are high-quality.
Facts from the thesis
What is blood rain?
- Blood rain occurs when strong sandstorms in North Africa lift large amounts of dust and sand into the atmosphere. These dust clouds travel across Europe, and when it rains, these particles fall to the ground, causing rain that can appear slightly red, especially on snow.
- Swedish soldiers deployed abroad experienced more frequent respiratory problems after deployment compared to those who had not served overseas.
- The study was carried out across three industries – a paper mill, a wood pellet plant, and a foundry – and assessed the exposure among 213 workers to silica dust, paper dust, and wood dust. Lung function was measured by spirometry and demonstrated varying degrees of impairment among participants.
- Respiratory symptoms increase in individuals reporting exposure to traffic and occupational air pollution. The most severe symptoms occur in those exposed to both.
- Link to the thesis: Dust Exposure as a Risk Factor for Respiratory Disease.
Text: Elin Abelson
Photo: Tord Saxin
Translation: Jerry Gray