Man-made chemicals found in all soil samples collected by Danish schoolchildren

Man-made chemicals have been detected in every soil sample collected by 30,000 Danish schoolchildren as part of a nationwide science project, according to a report by Danish broadcaster **DR**.

The findings, released by the national science education centre **Astra**, reveal that industrial chemicals and PFAS—often called “forever chemicals”—were present in all tested soil from 97 of Denmark’s 98 municipalities. Only **Læsø**, the country’s smallest municipality, did not participate.

Researchers from **Aarhus University, Aalborg University, and the Technical University of Denmark** analysed the samples, collected last September as part of the annual **Masseeksperiment (Mass Experiment)**. The project, supported by the **Nordea Foundation** and **Villum Foundation**, engages schoolchildren in large-scale scientific data collection.

**”It’s a wake-up call”**
Mogens Humlekrog Greve, the lead researcher and section head at Aarhus University, described the results as alarming.

*”I think it’s a wake-up call when we confirm that the situation is as bad as—or worse than—we feared,”* he told DR. *”This is the first time we’ve systematically examined soil in urban-adjacent areas, and the findings are concerning.”*

While the presence of chemicals has been confirmed, their concentrations have not yet been measured. Further analysis will determine levels of contamination.

**PFAS detected in 80% of samples**
The study found **PFAS (per- and polyfluoroalkyl substances)** in roughly **80% of the samples**, alongside other industrial chemicals. These synthetic compounds, used in products like non-stick cookware and firefighting foam, are known for their persistence in the environment.

Lene Christensen, programme director for Masseeksperiment, emphasised the reliability of the data despite being collected by schoolchildren.

*”The students aren’t trained lab technicians, but experience shows they gather high-quality data when given clear instructions,”* she said.

**Data to support EU soil monitoring laws**
Humlekrog Greve noted that the findings will aid Denmark in implementing the **EU’s Soil Monitoring Law**, which requires member states to track soil health.

*”We need to establish threshold values for soil health indicators, and this project has provided a goldmine of data we can draw from,”* he said.

The Mass Experiment has run annually since 2007, engaging students in hands-on science while contributing to national research.