21. The TARDIS lands on a rocky planet, which has breathable air but dangerously high levels of radioactivity . 22. Alarms went off at nuclear plants signaling dangerously high levels of radioactivity , but the state kept mum. 23. As late as July 2013 slightly elevated levels of radioactivity were found in beef on sale at Tokyo markets. 24. This event had no consequence on the environment, because of the very weak level of radioactivity of the discharge, 25. A heavy metal with low levels of radioactivity , depleted uranium is used in ammunition to penetrate tanks and other armor. 26. In March 2011, following the Fukushima I nuclear accidents, levels of radioactivity in Utsunomiya were 33 times higher than normal. 27. Encased in 2 inches of lead, the six counters were showing extremely high levels of radioactivity _ three times normal. 28. In January, the plant's No . 1 reactor suffered a dramatic jump in the level of radioactivity in a turbine. 29. We did not find levels of radioactivity that could pose a direct threat to the environment or to human health. 30. Depleted uranium, a dense metal with low levels of radioactivity , is used in artillery because of its ability to penetrate armor.
