The capital may lose its green lungs as many lakes in Hanoi are disappearing because of construction or have been heavily polluted by households waste for years.

Huu Tiep, or B52 Lake, in Ba Dinh District has historical value as a B52 plane was shot down and fell into the lake.

The wreckage remains in the lake but now it has been polluted with rubbish. Despite efforts to clean the water, people continue to throwing rubbish into the lake.

Meanwhile, Hao Nam Lake has lost some of its area due to the construction of a section of elevated rail line and the small area left is also full of rubbish.

Van Chuong Lake and even West Lake, especially the section near Thanh Nien and Nguyen Dinh Thi streets, are heavily polluted. On some hot days, the water even boils up with black bubbles.

According to research done by the Centre for Environment and Community Research in 2010 at 120 lakes and ponds revealed that 71% of the lakes in Hanoi were seriously polluted.

As rubbish keeps getting dumped into the lakes and people continue to build onto their surface area, many lakes in Hanoi may disappear.

The authorities have tried to dredge mud and grow rafts of anti-pollutant plants on affected lakes but the situation has not improved much due to the large amount of daily sewage.

About 650,000 cubic metres of wastewater is discharged into the river system each day.

However, the capital only has three waste treatment plants with total capacity of 206,000 cubic metres a day.

The Institute for Water Supply, Sewerage and Environment warned that Hanoi's underground water sources are also being heavily polluted.

B52 Lake polluted with rubbish

Large amount of rubbish in Hao Nam Lake

Heavily polluted Van Chuong Lake

Waste thrown by the West Lake