For twin sisters Noo and Zina Saro-Wiwa, the U.N. Environment award given their executed father is recognition that he tried to alert the world to the corruption that has infested his country.

"All you see as African men are despotic rulers," said Zina, the 20-year-old daughter of playwright Ken Saro-Wiwa. "It is important to have a symbol of an African man who has led a fight for the environment of his country."Ken Saro-Wiwa was one of 21 individuals and organizations honored Sunday by the U.N. for their efforts to clean up the environment. Others won for their writing, for their inventions or for their political drive.

Saro-Wiwa and eight other activists were executed by the Nigerian government last November.

They had been jailed for 1 1/2 years. Supporters say they were jailed for campaigning to get the government to clean up the homeland of the minority Ogoni people, which has been scarred by oil spills. The government says they were jailed for political murders, then convicted.

"There are so many multinational oil companies in the world which take advantage of the defenseless poor minorities who are governed by corrupt leaders. And that's what my father brought to the attention of the whole world," Zina said.

Thirteen-year-old Wahn Lee from South Korea was the youngest of the honorees. He became environmentally conscious five years ago when he realized the frogs in the creek near his house were dying because the water was polluted.

He started to write stories about the environment, then collected 18 in a book that was published last year. One story is about a fictional president who gives up his limousine and starts to ride a bicycle to keep the air clean.