Radioactive contamination transported to Western Europe with Saharan dust

Area of Science:

• Environmental Science
• Nuclear Chemistry
• Atmospheric Science

Background:

• The Reggane region in Southern Algeria hosted French atmospheric nuclear tests in the 1960s.
• This region is a major source of Saharan dust events impacting Western European air quality.
• A significant dust outbreak in March 2022 prompted a scientific investigation.

Purpose of the Study:

• To investigate the radioactivity carried by Saharan dust originating from Southern Algeria.
• To determine the source and characteristics of radioactive particles during a major dust event.
• To assess potential public health risks associated with radioactive dust contamination.

Main Methods:

• Collection of 110 dust deposit samples across six Western European countries.
• Geochemical and mineralogical analysis of collected samples.
• Satellite observations and back trajectory calculations to pinpoint dust origin.
• Isotopic analysis of plutonium to identify radioactive signatures.

Main Results:

• 53 samples were scientifically representative, confirming a South Algerian origin, including the Reggane nuclear test site.
• Plutonium isotopic signatures were consistent with global fallout from US and USSR tests, distinct from French signatures.
• Radioactive contamination was detected in all samples but posed no public health risk.

Conclusions:

• Saharan dust events can transport radioactive particles from historical nuclear test sites.
• The detected plutonium signatures indicate a mixed global fallout origin, not solely French.
• Despite detected radioactivity, the levels in the dust do not represent a significant risk to public health.