the most contaminated territory is in tula -lrb- 39.7 percent -rrb- , orel -lrb- 37 percent -rrb- , ryazan -lrb- 13 percent -rrb- , and kaluga -lrb- 11.7 percent -rrb- oblasts , but the contamination there is not great -lrb- mainly between 1 and 5 curies per square km -rrb- .