Growing various crops was the only source of livelihood for the people of Gorkhana, Chodurkhil, and Haldarchar -- three villages in Manikchhari upazila of Khagrachhari where the Halda river originates.
Farming in remote, rugged territory, they had to struggle to find buyers and were often forced to sell off their produce at low prices.
In 2007, farmers in these villages were approached by representatives of tobacco companies who proposed that if they cultivated tobacco, it would be bought from them at twice the market price.
Saira Begum, 45, of Gorkhana village of Manikchhari upazila, told The Daily Star they were tempted as the tobacco companies supplied seeds, fertilisers, and pesticides to the farmers for free.
Most importantly, she said, the companies would buy directly from their village, ridding the farmers of the hassle they face in selling their produce.
The farmers started growing tobacco as a cash crop and while it provided a steady source of income for them, it led to an environmental problem which became evident over the years.
However, the Integrated Development Foundation (IDF), an NGO, introduced an initiative in 2018 for farmers in the area to return from tobacco to other crop varieties, bringing about a change in just two years.
Now the three villages -- where farmers used to cultivate tobacco on around 400 acres -- have almost stopped growing this crop.
TOXIC RESIDUE, DECLINE IN EGG YIELDS
A large amount of toxic residue from the pesticides used in tobacco farming in these villages wash downstream into the Halda river, a 98-kilometre-long unique waterbody in South Asia where brood fish spawn naturally each year.
As the tobacco farmland increased at the hinterland -- one of several manmade hazards posing a threat to Halda -- the fallout the river faced was unprecedented.
Spawning reduced alarmingly in 2016 with no eggs laid by the brood fish in Halda.
Over the years, the river saw a massive drop in egg yields by brood fish from 211kg in 2011, to just 70kg in 2013, 47kg in 2015, and none at all in 2016.
This decline was blamed by researchers on tobacco farming.
Prof Dr Manzoorul Kibria, eminent Halda researcher, told The Daily Star that he had been observing that the volume of eggs laid by brood fish was declining.
This prompted the researcher to conduct a baseline study in 2016 to find the reason behind the decline of egg yields in the Halda since 2011, he said.
"As we were looking for the reason, we came across the large swathes of Halda hinterlands at Manikchhari where the Halda river originates.
"These had been engulfed by tobacco farming. As tobacco farming requires large amounts of pesticides and fertilisers, the toxic residue washed downstream causing egg production to slump."
Villager Saira Begum said, "We could never imagine the damage we are doing to Halda river. People of our village walked into their [tobacco companies'] trap.
"The tobacco growing was on the rise, thanks to the high profits. As production increased over the years, however, the company agents showed their real face by reducing the profit margins."
They also experienced some skin-related diseases due to the high amounts of pesticides they needed to use in cultivation. The profits they made from tobacco farming, they had to spend for their treatment, she added.
RETURN TO OTHER CROPS
IDF, the NGO, made villagers aware of the harm to their health and the damage to the river, arising from tobacco farming.
"Following all aspects of the situation, we returned to crop farming once again," said Saira.
Gias Uddin, another farmer from Chodurkhil village of Manikchhari, told The Daily Star that all they cared about was to live a better life.
"Tobacco once gave us that. But later we realised that our land is losing its fertility, our health is in jeopardy, and our environment is degraded."
The whole village has now left tobacco farming, he said.
Prof Kibria said he had earlier proposed to the relevant authorities to give an alternative to the farmers of Halda upstream.
IDF came forward to save the Halda and in just two years, the farmers were convinced to switch from tobacco farming, he said.
The Halda is also recovering and last year, the egg yield by brood fish in the river was 25,736kg, which is the highest in 14 years, according to the researcher.
Md Hasinur Rahman, Manikchhari upazila agricultural officer, told The Daily Star that they always discourage tobacco farming, due to its disastrous impact on the environment.
The tobacco companies lure them in many ways, he added.
"It is very motivating that the farmers changed from tobacco farming and took to other crop varieties. We have to keep this up."
Jahirul Alam, executive director of IDF, the project was undertaken following a report of The Daily Star published March 29, 2016.
In the beginning, he said, it was tough to move the farmers back to other crop varieties.
"We sat with them several times, convinced them of the negative impacts of tobacco farming, and supported the farmers with grants and other necessities.
"All these thing helped achieve the goal."
IDF also initiate a conversation with vegetables wholesalers and expects to get a positive outcome within this year, Jahirul added.