1. Woo ah, mercy mercy me Ah things ain't what they used to be, no no Where did all the blue skies go? Poison is the wind that blows from the north and south and east Woo mercy, mercy me, mercy father Ah things ain't what they used to be, no no Oil wasted on the ocean and upon our seas, fish full of mercury Ah oh mercy, mercy me Ah things ain't what they used to be, no no Radiation under ground and in the sky Animals and birds who live nearby are dying Oh mercy, mercy me Ah things ain't what they used to be What about this overcrowded land How much more abuse from man can she stand? Oh, na na... My sweet Lord... No My Lord... My sweet Lord MARVIN GAYE Mercy, Mercy Me

3. An environmental disaster is a disaster that is due to human activity and should not be confused with natural disasters. In this case, the impact of humans' alteration of the ecosystems has led to widespread and/or long-lasting consequences. It can include the deaths of animals (including humans) and plant systems, or severe disruption of human life, possibly requiring migration.

4. river. Hoover Dam

5. THREE GORGES DAM

6. Type: Concrete Gravity Dam Cost: Official cost $25bn - actual cost believed to be much higher Work began: 1993 Due for completion: 2009 Power generation: 26 turbines on left and right sides of dam. Six underground turbines planned for 2010 Power capacity: 18,000 megawatts Reservoir: 660km long, submerging 632 sq km of land. When fully flooded, water will be 175m above sea level Navigation: Two-way lock system became operational in 2004. One-step ship elevator due to open in 2009.

7. China's controversial Three Gorges Dam project. It will not be fully operational until 2009.

8. The project was begun in 1993 at an official cost of 200bn yuan ($25bn), though unofficial estimates are far higher.

9. In March the temporary cofferdam, which was used to block water while the main body of the dam was constructed, was destroyed.

10. The dam is already open to traffic.

11. When the dam's reservoir reaches its final height of 175m, scheduled for 2009, the five-chamber shiplock will raise boats by as much as 113m.

12. The primary aims of the dam are to alleviate flooding on the Yangtze River and generate power. Fourteen turbine generator units are already in operation.

13. At least 1 million people are being relocated to make way for the project.

14. A billboard in the port of Wushan shows the height that the water will reach, ultimately submerging all of its wharf facilities.

15. Those made homeless by the dam are being moved to new townships. Some say they miss their old homes; others are pleased to have modern facilities.

16. Despite the amount of effort that has gone into the dam, critics are sceptical that it will adequately control flooding and say silting may eventually clog up its turbines.