We examined the level of the Radon gas for the Kahramanmaraş Earthquake which occurred in February 2023. The concentration is increased 400%.

https://www.aa.com.tr/tr/asrin-felaketi/depremlerin-ardindan-kahramanmarasta-normalin-4-kati-radon-gazi-ortaya-cikti/2840814#

The second article is about decrease in the level than previous one. 

https://www.aa.com.tr/tr/gundem/depremin-merkez-ussu-kahramanmarasta-radon-gazi-seviyesi-dustu/2966708