A team of foreign and local researchers has detected excessive levels of toxic lead in turmeric powder available in the markets of a selected area, raising serious health concerns.
The findings came following an inquiry into the presence of lead in children's blood in Sirajdikhan of Munshiganj.
The team found that all 18 samples of turmeric powder collected from different households in the area contained lead, a heavy metal highly harmful to human health.
Of the samples, 12 contained excessive levels of lead -- up to 483 parts per million (ppm) -- that far exceeds the permissible limit of 2.5 ppm set by Bangladesh Standards and Testing Institution (BSTI).
The samples of turmeric powder were tested at a laboratory of Harvard School of Public Health of Harvard University in the USA.
The study was conducted jointly by the representatives of Dhaka Community Hospital (DCH), Harvard School of Public Health, and Boston Children's Hospital.
The findings were made public at a press conference at the DCH yesterday.
The researchers said they were yet to conduct similar studies in other parts of the country.
"It appears that use of artificial colour in turmeric powder is one of the reasons for lead contamination," said Prof Quazi Quamruzzaman, chairman of the DCH Trust.
Turmeric powder with high level of the toxic metal was primarily responsible for lead contamination in the blood of 284 children, aged between 20 and 40 months.
A high level of lead -- above 5 microgram per decilitre -- has been found in the blood of 80 percent of the children, while 10 microgram per decilitre of lead has been detected in the blood of 26 percent of the kids.
The researchers collected samples of water, soil, dust, rice, chilli and turmeric from the children's homes to know the source of lead in their blood.
No lead was found in the water samples tested at Bangladesh University of Engineering and Technology (BUET).
A tolerable level of lead was found in soil examined at the laboratory of Harvard School of Public Health.
The other samples will be tested later, according to a DCH statement.
Quamruzzaman said more work needs to be done, as the study involved “a minimum sampling” in a country of 16 crore.
"To get the answers to all questions, we will carry out random survey throughout the country," he said.
The study was conducted between 2012 and early this year to find out whether presence of arsenic or any metal in the mother's body has any impact on the child's health.
"We are surprised to find high levels of lead in children's blood although we were not expecting to find that. There should be no lead in children's blood because it is highly toxic for them," said Maitreyi Mazumdar, staff neurologist of Boston Children's Hospital.
"Lead exposure has many health consequences for children. Lead is associated with cognitive deficits. Children with lead in blood do worst in schools and they cannot reverse that because it damages their brains permanently," said Maitreyi, who led the team.
Lead also causes heart and kidney problems, speech and language impairment, and affects muscle and bone growth.
High levels of lead in blood could be life threatening and could cause seizures, unconsciousness and death, said the DCH statement.
Quamruzzaman said food contamination contributes to kidney failure and heart diseases, and presence of lead in blood is a reason for the spread of these diseases.
The joint research team found lead in turmeric powder before the US Food and Drug Administration (FDA) detected lead in Pran's turmeric powder last month, he said.
Later, Bangladesh Council of Scientific and Industrial Research and the BSTI also found lead in Pran's turmeric.
The researchers said they tested samples of turmeric powder collected from the children's homes, not those of any particular brands.
"We waited for sharing the findings because we wanted to be sure," said Quamruzzaman.
The use of powdered spices in families is on the rise across the country, and various types of chemicals and methods are used in processing those.
“It is necessary to examine all these chemicals and methods," said the DCH statement, urging the government to strictly monitor the market to ensure food safety.
Quamruzzaman said those involved in using toxic chemicals in turmeric powder should be given exemplary punishment.
Mahmuder Rahman, member and coordinator of the DCH Trust, said a detailed research is needed to detect the source of lead contamination in turmeric powder and determine whether the heavy metal comes from soil or during the post-harvest and processing phase.