Excessive lead residues in almost all the 266 samples of raw and pasteurised cow milk and cadmium in all the samples that the Bangladesh Food Safety Authority found in April–May have the authorities worried, leaving them to look for further leaks in dairy value chain.
‘We are worried about widespread lead contamination in cow milk,’ said Mahbub Kabir, a member of the Food Safety Authority.
‘There could be a number of sources for heavy metals to get into the milk — fodder, adulterated pesticides, fertilisers and industrial pollutions,’ he said.
Experts and green campaigners have for long opposed unplanned industrialisation, especially the dumping of untreated industrial wastes into rivers which adds to the risk of chemicals getting into the food chain.
They have raised the concern again as public and private research has over the years noted that soil health continue to decay for an excessive use of fertiliser adulterated with metals such as lead, cadmium and chromium.
‘Grass or other plants absorb metals available in soil,’ said Abdur Razzaque, an agricultural chemistry teacher in Sher-e-Bangla Agricultural University. ‘Metals can enter cow’s body through grass or other plants.’
Razzaque, however, doubted whether natural sources were the only way for metals to get into cows in such amounts as tests detected.
The permissible limit of lead residue in milk is 0.02 milligrams a kilogram.
The Food Safety Authority, in tests done in two government and three private laboratories on a High Court order, found up to 0.12 mg/kg of lead residue in both raw and pasteurised milk samples.
All the 194 raw milk samples were collected from 50 sources — individual farmers and milk collection centres of the companies — in 10 districts.
Samples of pasteurised milk that 10 out of 11 companies produce and market were no better in test results.
Industrial pollution may have had a role in the contamination of milk collected from Dhaka, Gazipur, Narayanganj and Chattogram, having a large number of industrial units, experts said.
But experts find hardly any reason for milk contamination because of industrial pollution in Sirajganj, Pabna, Sylhet, Mymensingh, Bogura and Cumilla that do not have too many industries.
Razzaque said that the cattle feed used to fatten cows or increase their milk production could be a significant source of metal contamination.
Cows are fed calcium imported in bulk without being properly tested to see if in contains any harmful substances, he said.
Concentrated protein and fibre, often mixtures of ingredients mostly from unverified sources, could also be contaminated with metals, he said.
But the Food Safety Authority in found nothing wrong with 48 samples of fodder produced by 12 leading feed producers tested on the High Court order.
There are other small companies, accounting for 92 per cent of feed consumption, that are still outside any regulation, livestock officials said.
The Department of Livestock Services seized several thousand tonnes of Bangla Protein, concentrated protein locally made of chromium-treated tannery wastes, in raids on places in Dhaka and Savar in the past two years.
Studies have found animal protein contaminated to a dangerous level with metals such as lead and cadmium since 2009.
The Institute of Public Health detected lead in almost a quarter of 30 cow feed samples tested, cadmium in all the samples and chromium in 76 per cent of the samples on February 10. Chromium in 69 per cent of the samples was beyond the permissible limit.
Feed samples tested were collected directly from dairy farms in Dhaka, Gazipur and Narayanganj.
Testing 96 samples of raw cow milk and 31 samples of packaged milk,
The institute also found 96 samples of raw cow milk and 31 samples of packaged milk to be contaminated with microbes and chemicals.
All raw cow milk samples contained pesticide residues beyond the permissible limit; 15 per cent of them contained excessive lead residues and 13 per cent contained excessive residues of drugs, mainly antibiotic. Lead, antibiotic and aflatoxin were found in packaged milk.
The study prompted the High Court to order the Food Safety Authority on February 11 to test raw and pasteurised cow milk and fodder.
The tests were done at the Bangladesh Council of Scientific and Industrial Research, the Atomic Energy Commission, the International Centre for Diarrhoeal Disease Research, Bangladesh, WAFFEN Research Lab and Plasma Lab.
The report was submitted to the High Court in July, officials said.
On hearing the Food Safety Authority and the Bangladesh Standards and Testing Institution, the court posted for October 20 an order on the issue.
Additional livestock secretary Kazi Wasi Uddin admitted that they needed to go a long way to ensure safe milk. ‘We need to change our agricultural practices and strengthen monitoring and food testing capacities.’