:: A giant coal-fired power plant approved by Bangladesh could drastically worsen air pollution for millions and cause the early deaths of 6,000 people over its lifetime, Greenpeace said Friday.

Bangladesh is constructing the 1,320-megawatt power plant on the edge of the Sundarbans, the world’s largest mangrove forest, despite warnings the controversial project threatens the fragile ecosystem and human health.

The UN has already urged Bangladesh to halt construction, warning it poses an unacceptable risk to the UNESCO-protected mangroves that provide a barrier against deadly storm surges and cyclones.

But in a new report Greenpeace warned emissions from the plant represented one of the single largest threats to air quality for millions living across Bangladesh and as far as neighboring India.

“Over its operational lifetime, the plant’s emissions will increase the risk of stroke, lung cancer, heart and respiratory diseases in adults, as well as respiratory symptoms in children,” stated the report released Friday.

“People in Dhaka and Calcutta (India), particularly children and the elderly, would also be harmed. Even if Bangladesh currently had zero air pollution, the plant alone would cause the premature deaths of 6,000 people, and low birth weights of 24,000 babies.”

The plant at Rampal in Bangladesh’s south-west could also deposit enough mercury to render fish unsafe to eat for millions living across the Bay of Bengal, and devastate the aquatic food chain of the Sundarbans.

The plant — a joint project by India and Bangladesh — would be powered by nearly five million tons of coal shipped every year along the mangroves’ fragile waterways, a natural habitat for endangered Bengal tigers and rare Irrawaddy dolphins.

Scheduled to open in 2018, the plant is projected to discharge nearly 125,000 cubic meters of chemically-tainted water every day into nearby water catchments, Greenpeace said.

The UN warned in October that the plant would “irreversibly damage” the pristine forest, which was declared a UNESCO World Heritage site in 1997.

The dense mangroves provide a buffer against violent weather roaring into the delta, which has killed thousands living in impoverished coastal villages and islands in recent years.

There was no immediate comment from Bangladeshi authorities or the joint-venture company bankrolling the $1.7-billion plant.

Bangladeshi Prime Minister Sheikh Hasina has defended the project and rejected concerns about its impact as politically motivated.

The project has galvanized street protests in Bangladesh, with campaigners calling for the plant to be scrapped or relocated.