The coal rolling down along with sand in the rainy season lie hidden under in the river bed. People, mainly women and children, collect those by digging the riverbed, affecting the environment and the ecology.

The mineral is collected from the riverbed from Bijoypur to Birishiri, stretching about 10 kilometres. Women and children collect it from morning to sunset.

Baromary, Buranga, Dashal, Ghagra, Balikandi, Thakurbari-Kandi, Majiail, Jianagar, Mujibnagar, Dhanstra, Farongpara, Debthail, Shibgonj, Bhulipara and Bijoypur of Durgapur upazila areas are the main spots from where the coal is collected.

Normally, one person can collect one to one and half maunds, which earn him Tk 60 to 70 a day. This way, 25 to 30 tons of coal are collected everyday.

Local administration sources said there is neither any restriction not any tax for the coal collection. But some local coal traders talking to this correspondent said they have to give Tk 100 per ton as toll to ruling party activists. They sell one maund of coal at Tk 100 to 110, mainly to local brick fields.

They are also exploited because they can not carry the mineral to other places due to bad communication system. Coal traders from outside also do not come to the area due to for this, they said.

Amena Begum, 35, of Majiail village said she has been collecting coal for five years. She said she does not get a fair price of her labour as she has to accept whatever offered by local traders. She can collect one to one and a half maunds daily.

Rehena Khatun, 16, an unmarried girl from Shibgonj village, is engaged in coal collection for about six years. "It is a hard work but we do not get a fair price", she said. She earns Tk 70 to 100 daily.

Coal trader Amir Hossen said he is compelled to sell coal bought from collectors to local brick fields as he can neither carry those to other areas nor any trader comes to the area from outside due to bad communication.

"We could pay them (collectors) better if we could sell those at higher prices", said another trader Ali Akbar.

Local environmentalists said indiscriminate and unplanned collection of coal from the river bed will ultimately change its course which will increase floods and erosion. Fishes are also depleting as their sanctuaries are being destroyed. The government should either stop it or allow planned collection, they said.