Ambassador-at-large Tommy Koh said he hoped the transformation, catalogued in 'Clean, Green and Blue', would be an inspiration for other countries looking to embrace environmental awareness.

He was speaking at the book's official launch on Tuesday, which was held in conjunction with the President's Award for the Environment ceremony at the Istana.

The award honours individuals, organisations and companies that make contributions to keeping Singapore green.

This year's winners were the Alexandra Hospital, power generation company Senoko Power and the Southwest Community Development Council.

Clean, Green and Blue was penned by permanent secretary for the Ministry of Environment and Water Resources Tan Yong Soon and his colleagues.

'The book shows how hard won our pollution free environment is,' noted Professor Koh, who was one of the inaugural recipients of the President's award.

'We cannot take the environment for granted.'