Radiation in Ticino: Forty years after Chernobyl, an increasingly advanced monitoring system

On April 26, 1986, the explosion of reactor number four at the nuclear power plant Chernobyl Nuclear Power Plant It caused the most serious civilian nuclear accident ever recorded. The resulting radioactive cloud swept across much of the European continent, leaving traces even in Switzerland.

In Switzerland, the most significant depositions were recorded in Ticino, St. Gallen, and Thurgau, thanks to a rainfall event in early May of that year. It was then that the Cesium-137 settled on the ground, marking the beginning of a long phase of environmental monitoring.

Forty years later, the radiological impact has significantly reduced. Natural physical decay has led to a reduction of more than 50% of the initial contamination. Today, it is estimated that approximately 40% of the cesium deposited in 1986 is still present, but at levels similar to natural background levels.

From crisis to building an efficient network

While the Chernobyl accident represented a turning point, it also triggered a profound transformation in radiation protection systems. In Switzerland, measurement organization has evolved significantly, moving from limited instruments to a complex, automated, and constantly updated network.

Today's surveillance relies on a combination of advanced technologies and sophisticated predictive models. Thanks to data processed by MeteoSwiss, it is now possible to accurately simulate the dispersion of any radioactive clouds, providing timely information to the authorities.

At the same time, Switzerland plays an active role at the international level through the National Alarm Center, which acts as the competent authority on behalf of theInternational Atomic Energy AgencyThis enables the seamless exchange of information across European and global platforms, including the EURDEP system.

The control system also includes mobile vehicles, helicopters for aerial radiometry and the support of specialized NBC (Nuclear, Biological, Chemical) units, as well as intervention forces such as the SCAM CENAL.

Ticino's strategic role in monitoring

In the national panorama, Ticino occupies a prominent positionThe Cantonal Laboratory of the Department of Health and Social Affairs has been recognized as one of the seven Swiss centers of excellence for the analysis of radioactivity in foodstuffs.

Monitoring efforts, which began immediately after 1986, have never stopped. Over four decades, over one hundred surveys have been conducted on 59 different environmental and food matrices.

Particular attention was paid to wild mushrooms, considered sensitive indicators of soil contaminants. Analysis of nearly eight hundred samples collected from various districts in Ticino revealed a significant reduction in Cesium-137. Today, almost all edible mushrooms have levels well below the limits established by federal regulations.

Tests on grass, milk, and soil also confirm a reassuring trend: the transfer of radioactivity along the food chain is now negligible.

Continuous surveillance and response capacity

Although the current risk level is considered minimal, the authorities remain highly vigilant. Over the years, the regulatory framework has been strengthened, and coordination between the Confederation and the cantons has become more efficient.

In Ticino, a specialized working group is responsible for developing and updating intervention measures in the event of new radiological events. The goal is to ensure a rapid response, based on reliable data and a detection network capable of promptly identifying any anomalies.

During a press conference held on April 21, 2026, the director of the Department of Health and Social Affairs, Raffaele De Rosa, he underlined how the Chernobyl experience has contributed to building one of the most advanced control systems, capable today of ensuring both early detection and the safety of food products.

A consolidated system, between memory and prevention

Forty years after the accident, the radiation issue in Ticino is profoundly different than in the past. While uncertainty dominated in the 1980s, today an approach based on scientific data, technology, and international cooperation prevails.

Constant monitoring, combined with simulation capabilities and operational readiness, represents the most tangible result of a process built over time. A system that, despite being born out of a crisis, continues to evolve with the goal of ensuring safety and transparency for the population.