A quiet town in Croatia's Lika region has become home to the country's most puzzling environmental anomaly. Gospić recorded a 961% jump in radioactive strontium-90 in its surface soil between 2023 and 2025, according to annual reports from the Zagreb Institute for Medical Research and Occupational Health (IMI), published on the Interior Ministry's website. Activity per square metre rose from 24.5 to 260 becquerels — nearly eleven times higher in just two years.
Here's the strange part: strontium-90 doesn't exist in nature. It's created by nuclear fission, and according to IMI's Radiation Protection Department, every trace of it on Croatian soil dates back to the 1986 Chernobyl disaster. With a half-life of 28.8 years, roughly 38% of the original deposit remains, and levels should only decline over time — unless there's a new source. Elsewhere in Croatia, that's exactly what happened: levels fell in Zadar, Osijek, Buzet/Pula and Opuzen between 2023 and 2025. Zagreb saw a rise of about 92%. Gospić alone went from having the lowest reading of five measuring points to the highest.
There's no evidence linking the spike to the illegal waste site at the former PPK Velebit in Gospić's Bilajska Street — the measuring point sits about 7.6 km southwest of it. But no alternative explanation has been offered either. An unnamed radioactivity expert consulted by Index was blunt: a multiple increase without a new contamination source would be 'a perpetual motion machine.' His best guess is flawed sampling or imprecise lab work, noting that Sr-90 measurement near detection limits is notoriously difficult, with analyses taking about three weeks.
What's perhaps most striking is the institutional shrug. IMI says it can't order extra sampling on its own — the Interior Ministry, as the client, decides, and no request for follow-up testing in Gospić has been made. The last measured value of 260 Bq/m² isn't a historical high (Gospić recorded 440 Bq/m² back in 2003), but monitoring lapsed entirely from 2007 to 2022 before resuming in 2023, so there's a long blind spot. Meanwhile, the Croatian Institute of Public Health reportedly said it 'doesn't deal with' health-risk questions, and the Interior Ministry's Civil Protection Directorate ignored repeated inquiries.
Importantly, this isn't a confirmed health crisis. Soil concentration per square metre is not the same as the radiation dose residents actually receive, and without dose or food-chain studies, no conclusion about danger — or the absence of it — can honestly be drawn. IMI says health-risk assessment falls outside its monitoring contract.
For travellers, Gospić sits on the road between Zagreb and the Adriatic coast, near Plitvice Lakes, and there's no advisory against visiting. The real story here is accountability: an anomalous reading that repeated in consecutive years, and an apparent reluctance by any institution to commission a second look. Anyone heading through Lika should simply know that this story is still developing, and that local reporting — in this case by Index's Slobodan Mufic — is keeping the pressure on. Full credit for the original reporting goes to Total Croatia.
