Miniscule amounts of radioactive iodine and cesium have been detected in Seoul’s atmosphere.

An environmental radiation monitoring center at Hanyang University in Seoul said Tuesday that tiny amounts of iodine and cesium were found in Seoul's air sampled during the past five days. However, the center was quick to stress that the amount of radioactive materials found was very small and would have no effect on the environment or the human body.

The center said traces of iodine have never been detected in the nation before, adding that the radioactive material is likely to have come from Japan's quake-crippled Fukushima nuclear power plant.

As for the detected cesium, the center said it has yet to determine whether the material came from the Japanese nuclear power plant or from China.

The center’s announcement comes after minimal amount of the radioactive substance xenon was detected in the air on the eastern coast of Korea in Gangwon Province last Wednesday.