Melamine Contaminated Milk

chinese-boyA brief summary and update to the Sciencebase original posts on Melamine in Milk and Melamine Scandal Widens.

Dairy farmers have been feeling the squeeze for years, particularly in parts of the world where technological advancement has been slow in coming and so their profit margins on their milk output have not been lifted by improved efficiency. In order to boost profits milk has been diluted. However, this brings with it the problem of falling quality – dilute with water and measurable concentrations of milk proteins, fats, and sugars fall. Dilution by up to 30% has not been uncommon, which is where melamine (as I’ve mentioned) comes in. Melamine is a small organic molecule with a high nitrogen content that can easily fool the quality control equipment into thinking that nitrogen (from protein) is present at normal levels and so the milk is passed as good.
Unfortunately, it is possible that melamine accumulates in the body and causes toxicity problems – basically damaging the kidneys and forming stones (solid deposits within the kidneys or bladder). Infants fed regularly with milk containing melamine will be particularly susceptible to these effects. As we have seen tens of thousands have been affected and several have died in China. Why this problem is not more widespread, given the rather large number of infants potentially having been drinking contaminated formula-milk for months is unclear.

Hsieh Teh-sheng, director of the Taiwan Urological Association and chief of Cathay General Hospital’s Department of Urology told the Taipei Times, that while there is no direct toxicity information on melamine’s health effects on people, the level of melamine found in the milk products is “not particularly high”. He says that kidney stones or other effects blamed on the melamine “could just as easily be caused by other harmful chemicals,” which is a point I discussed in the original post.

However, cyanuric acid is often present in melamine samples and the two can react together to form crystals, which can form stones. The current scandal could, whatever the final outcome, provide researchers with useful data on the effects of chronic exposure to melamine and its toxicity to the kidneys and bladder.

Sources in China have now said that Sanlu, which is at the heart of the controversy, was aware that its products were contaminated with melamine as long ago as December 2007. Fonterra, the New Zealand dairy company and 43% stakeholder in Sanlu claims to have approached the Chinese authorities as soon as it heard about the problem but was held back from going public because of the imminent Beijing Olympic Games. One can imagine there were additional pressures that prevented Fonterra from pushing for a solution. But, it cannot blame Chinese regulations for it failing to warn consumers as soon as it knew about the contamination.

Products across the globe containing milk imported from China seem to have been affected and authorities from Australasia and Asia to Europe and the US are withdrawing formula milk, coffee and tea drinks, candies, soup, cheese powder, biscuits, ready-made desserts, and chocolate. however, there are calls from some commentators that the US Food and Drug Administration (FDA) should be more forthright on its recommendations for consumers concerned with the melamine in milk scandal.

For those thinking of testing the products in their store cupboard, there’s a Craigslist item for sale here. It’s described as a “Rapid Melamine test kit—AgraQuant Melamine ELISA test kit”.

But, before you grab your credit card, think carefully whether you’d like to make ELISA (Enzyme-Linked ImmunoSorbent Assay) your friend. It’s a tricky test and probably not one you could rattle off in an afternoon with at least some biomedical background. Also, there’d be no point in testing your Ikea furniture for melamine, the “Melamine” they use is a polymer resin (a plastic, in other words) made from the small organic molecule melamine and formaldehyde, and no there’s no need to worry about using melamine cooking utensils or eating off a melamine-coated kitchen table.


20 thoughts on “Melamine Contaminated Milk”

  1. RE: Melamine Dishes & Utensils

    Back last year some countries (Kuwait in the link below) were banning Melamine utensils/dishes due to cheap glazing wearing off and allegedly increasing exposure to the toxins.\09\06\story_6-9-2007_pg7_34

    “A large number of organic compounds are toxic and melamine is also considered toxic, the official said. A layer of glazing powder is used to prevent contact with the human body but with use the utensils lose this protective layer and thus can be harmful to humans, the official added. ”

    “Dr Bilal of Services Hospital, said that the number of patients complaining of intestine, stomach and throat problems is on the rise. He said that modern research has shown melamine and formaldehyde are responsible for such diseases. The government should ban this industry or regulate the industry to ensure higher quality products.”

    “Rana Rizwan, a melamine utensil factory owner, said melamine costs Rs 115 per kg and so by mixing starch (kuluf), which costs Rs 35 per kg, the production costs of utensils is lowered. The producers also apply a lower quantity of glazing to the utensils to reduce costs, he added. Both these result in lower quality of the product and the glazing soon wears off, he added. “

  2. @paul said on September 30

    “One source I read says the farmers add urea”

    I can think of a very cheap and widely available source of urea…

  3. Thanks for a great insight into the current melamine issue. One thing I was thinking when reading is that since approx 80%of Chinese are lactose intolerant (quoting Wikipedia), they may be using soy based formula instead of milk based and that could account for the relatively low numbers.

    As a mom to 2 kids adopted from China and whose family (of 5) is currently now living in China, this is an issue that is very close to my heart. I appreciate your insight and will be checking back for updates.

  4. Regarding this Melamine, a world wide awareness should be done because to increase the nitrogen content & fool the tests for protein level in Milk formula the Melamine is added by producers. Same application is possible for Animal feed also. Eg. Fishmeal & soymeal are added to poultry feed and certain crude protein level is maintained in poultry-Broiler chicken feed at different ages. Usually this fishmeal raw material should consist of about 65% crude protein and Soyameal should consist of about 48% crude protein, so the suppliers or producers of this fishmeal & soyameal may add melamine to increase or fool the test for protein level. There is a possibility for that this Melamine get accumulate in chicken muscles which consume the above feed and reach human body finally.

    so this is very important to find ways to get rid of this contamination.

    U L Abdul Raheem

  5. AS long as we continue to import food products from a country sworn to destroy US then we are getting just what we deserve. I’m sorry but, if all that is important is the profits realized by the companies and not the safety of the population in general then it’s too bad. If we ever go to war with China we will have to do it barefoot. All the shoe manufacturers have gone there also. All your computer boards are made there. They don’t need spys. Just wait we’ll give it to them to build for us.

  6. I am still puzzled at how the raw milk suppliers add melamine into their diluted milk if melamine is not very soluable in water? One source I read says the farmers add urea and then when milk is turned to powder in high heat, the urea turns into melamine. But then when you add hot water and feed it to an infant, the melamine can still dissolve? Or is it only a small enough amount that it dissolves?

  7. Laura – thanks for spotting that, it was a typing error. Melamine and cyanuric acid co-crystallise but obviously don’t produce uric acid crystals, I’ve fixed the text. However, the reference to coffee drinking and low water intake was not meant to be in reference to melamine, but to the risk of kidney stones for anyone drinking lots of caffeine and little water. I’ve clarified the text in that regard.

  8. Your statements regarding melamine related kidney stones and kidney stone risks are slightly incorrect and potentially misleading.
    Melamine and cyanuric acid do not form ‘uric acid’ stones. They form melamine-cyanurate stones, which are completely different from uric acid. For example, you seem to imply that consumption of melamine in milk together with coffee consumption and low water intake might put someone at a higher risk for these stones. That is not correct.
    My guess is that this suggestion is guided by the fact that reduced water consumption and diuretic use (such as coffee) can exacerbate kidney issues related to uric acid. That is because uric acid is still quite water soluble and so, higher water consumption can largely prevent over-concentration of uric acid into uric acid stones. This is not the case with melamine-cyanurate. Melamine, and melamine-cyanurate are almost completely insoluble in water. They form these stones in kidneys in a large part because the pH in the kidneys is perfect for them to bind together, and only partially because of the concentration effect. So, while water consumption is important for overall health, it is not a risk factor people should be focusing on to reduce their risk for melamine-cyanurate kidney stones.
    All the epidemological and food surveilance information to date (9/30/08) suggest that melamine related kidney stones are isolated to formula fed infants in China and Taiwan between late 2007 and August 2008. Additionally adults seem to be able to process much larger quantities of melamine contamination without these kidney problems. As a result I would encourage folks to focus on infant risks.
    Finally while one doctor’s statement that melamine levels were ‘not that high’ may seem to bolster the idea that there is more than melamine in the infant health problems in china, I would highly doubt it for a number of reasons. 1. He was not looking at the full range of melamine concentrations in products. In economic adulturation cases such as these (especially when offenders are using such low grade starting material) actual concentrations can vary several order of magnitude, and a one time measurement does not capture what the concentrations have been over the lifetime of the infants in question. 2. His idea that melamine was ‘not that high’ may be irrelevant when the compound in question is really melamine AND cyanuric acid forming melamine-cyanurate salts in the kidneys. It is abundantly clear that melamine and cyanuric acid when co-ingested are harmful at concentrations an order of magnitude lower than either one alone. 3. The suggestion that ‘other chemicals could just as easily explain’ infant kidney problems in china misses the fact that there is a documented mechanism by which melamine and cyanuric acid contaminated food damages kidneys, causes kidney stone and failure in mammals. The concentrations of melamine in infant formula reported to date (100s of ppms) is more than sufficient to cause these exact effects. I have heard of no such evidence for any other compounds and I have heard of no problems with the melamine-cyanurate hypothesis fitting the symptoms of affected Chinese infants.

  9. I am actually surprised that melamine has turned out to be such a huge story. More than a year ago during the pet food scandal, there are news reports coming out of China that melamine was used in human food, such cake and other pastries to get better texture. Melamine had been assumed to be relatively safe for humans and pets were supposed to be the anomaly.

  10. I posted a comment to your previous article wondering about the effects of long term exposure to melamine (an open question you note above as well). In the reply comments I was directed to an article with “translations” of the FDA S/RA, quite helpful to me as I’m not a toxicologist. From this I understood that related open questions include what happens upon heating melamine, and what happens in dehydrated kidneys.

    For what it’s worth I thought I’d add that in China, baby formula (either prepackaged, or homemade using with milk powder and rice cereal) is boiled in order to kill contaminants in the water (all water must be boiled – in the finest hotels, the maids bring to you your thermos of boiled water each morning). It’s actually shocking how hot the babies learn to take their bottles. Who knows (apparently no one) what impact, if any, this has upon any melamine that might be present. Secondly, malnutrition and diarrhea in children are common problems in some areas of China; dehydration (and perhaps kidneys worse at clearing melamine) would be present as well. Finally, I do not know how common breastfeeding is in China, although it’s easy to find news stories this week on the “wet nurse revival” for Chinese parents of means.

    One does wonder why the problem is not more widespread than we have heard. I would venture to guess that it is widespread, but even with the best of intentions it is very hard for the Chinese government to collect and disseminate data on its vast, and often rural, population. They don’t even really know how many people they have, let alone if or how many babies and children have fallen ill due to this specific problem.

    Thanks for this helpful thread.

  11. Dr Ahmed, thanks for your positive comment, I wonder if, having linked to NADEC whether you would share your personal opinions of the melamine contaminated milk debacle.

  12. The introduction of (technology based) efficiencies in milk production (and/or anything else) produces temporary profit increases for early adopters only. In unhampered markets, such competitive advantages (and the boosted profits they bring) dissipate very quickly as competitors acquire the same (former) advantages as a necessary step in remaining competitive (in business).

    Technological advances in the dairy industry are no more capable of improving industrywide profitability over any significant length of time than they are in any other industry. Like market participants everywhere, all the time, milk producers will continue to “feel the squeeze” of competition for as long as competition is permitted (not much longer in industries like finance in the US).

  13. I think if parents are using competitive, sandwiches, (pizza, cookies) ELISA they must be more ready to design a formula milk powder directly.

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