Poultry and egg - two popular and affordable protein sources - are not safe anymore as chickens are fed highly toxic tannery waste and excessive antibiotics, two studies have found.
Use of tannery waste lowers the production cost of poultry feed while antibiotics help to reduce deaths of chicks. But the practices pose serious health risks to consumers already worried at reports of formalin and other chemicals in food.
However, experts say, there is no reason to panic yet as the public health disaster caused by chromium from poultry feed to the human body can easily be avoided.
Nevertheless the government has yet to clamp down on tannery waste traders and launch awareness campaigns on a proper use of antibiotics, they add.
Recently, a Dhaka University study found traces of chromium ranging from 249 microgram (mg) to 4,561mg per kg in chickens that consumed feed manufactured with tannery waste. The permissible limit is 10-60mg.
Prof Mohammad Abul Hossain of Dhaka University's chemistry department along with his student Zubair Hasan conducted the study in 2008 and this year. Their findings were published online by the International Journal of Civil, Structural, Environmental and Infrastructure Engineering Research and Development on June 28.
With the support from the Bangladesh Council of Science and Industrial Research (BCSIR), the researchers in the journal said they had collected samples of tannery waste from Hazaribagh, Dhaka, and poultry feed from a city market to conduct the study.
"The excess amount of chromium can be transported from poultry feed to the human body through the chicken, leading to the carcinogenic effects on human beings like cancer, ulcer, liver cirrhosis and kidney damages, etc," they said.
Another research conducted by the Bangladesh Agricultural Research Council (BARC) in 2012 and 2013 said about 48 per cent poultry feed contains tannery waste. It also detected antibiotics in eggs and chicken far beyond the acceptable limit.
BARC is the apex organisation of the national agricultural research system. Its main responsibility is strengthening the national agricultural research capability through planning and integration of resources.
At the farm level in Bogra and Joypurhat, antibiotics -- ciprofloxacin and sulphonamide -- were found in chickens at up to 96.40 mg a kg. At the market level, it was up to 217.50 mg a kg, the study said.
Chicken eggs collected from Dhaka, Chittagong, Sirajganj, Joypurhat and Munshiganj were found to have contained antibiotics -- ciprofloxacin -- from 37 mg to 460mg a kg while its permissible limit is only 30mg.
And in 80 per cent of the eggs, other antibiotics -- sulphonamide, oxy-tetracycline and enrofloxacin -- were found in a range of 30-570mg a kg though the limit is only 100-120mg per kg.
"Antibiotics are used more at the sales points to protect chicks from diseases and death. To avoid risks, traders use antibiotics that exceed the permissible levels until the sale of chickens," said Dr Nathu Ram Sarker, senior scientific officer at Bangladesh Livestock Research Institute in Savar.
There is risk of developing antibiotic resistance from consuming chicken and eggs beyond the permissible level.
This means if similar antibiotics are prescribed for any disease, it will not work, and it will pose a major health risk, added the officer.
Prof Hossain told this correspondent that Bangladesh used to import various proteins for mixing in poultry feed. As those are expensive, a section of feed manufacturers started using protein generated from tannery waste at Dhaka's Hazaribagh.
Over 200 tannery factories in the area produce tonnes of solid waste every day.
"Cowhide contains high protein. This is why feed producers target tannery waste," he added. But as industries use chromium and other chemicals in tanning hide, the chemicals remain in the feed prepared for poultry.
Large amounts of tanned leather off-cuts and shaving dust generated from the tannery are unusable. But some traders collect such waste and boil and dry it before selling it to middlemen.
"The middlemen then grind the dry waste and supply it to the poultry feed mills or farmers," Hossain said, adding that chromium thus enters the food chain.
Munir Chowdhury, former director of the environment department, who conducted mobile court drives in Hazaribagh in 2011, said the traders pack the stuff with various local and foreign labels and distribute it throughout the country.
A tannery worker at Hazaribagh said it is a win-win business for both tannery workers and local traders. Many of the tanneries that earlier used to dump the waste into the Buriganga river now sell it to traders.
"Many locals are engaged in the trade. The factories grinding the dry waste are small and clandestine in nature, so they can easily avoid law enforcers," he said, seeking anonymity.
Khandker Mohammad Mohsin, general secretary of Poultry Farm Protection National Council, said the findings don't appear true to him.
"I have visited Hazaribagh, and found no (poultry feed) factory," he said. "Protein is only 3-5 per cent of total feed, and it is imported."
He added some poultry farmers might be using antibiotics unknowingly, although their number is very small.
The Department of Livestock Services, which oversees feed quality and animal health, says there is no registered feed mill in Hazaribagh.
"However, if we have information about anyone making adulterated poultry feed, we can take action," said Dr Mozammel Hoque Siddiquee, director general of the department.
The department filed a case against a feed factory in March this year for operating without a licence and selling feed having chromium beyond the approved limit.
There are 58 registered feed mills mostly in Gazipur and Dhaka districts. The department checks the feed quality and mill hygiene before renewing licences every year.
Another official said antibiotic residue in chicken or eggs can be found within seven days of slaughtering or laying eggs.
"There is no arrangement for regular tests of antibiotics due to shortage of manpower and logistics."
Sharifuzzaman Sharif, general secretary of the citizens' body Nagorik Samhati, said whenever there are issues of quality food, the authorities tend to come out with excuses behind such happenings.
"This is totally unacceptable. For the greed of a few, the whole nation cannot suffer. We want to get rid of the toxic foods. The government must act immediately," he said.
"A person selling adulterated food in a hotel will buy chemical-tainted mangoes. The one selling such mangoes will buy chicken with chromium. Thus we are all victims.
"So let's change ourselves in our own interest."