Tuesday, October 7, 2008

Melamine hysteria - or ...why is AVA not forthcoming?


Today's press carried a report that Malaysia was going ahead to test their vegetables for melamine. I guess being an agricultural country, they have to...but it's probably going to be a waste of time and money. Melamine isn't all that toxic, and so far only appears to be problematic for infants who consume disproportionately large amounts through tainted milk formulae. The main problems are related to formation of renal stones and consequent renal failure. There is no apparent association with cancers.

Melamine generally finds it's way into synthetic milk products where producers try and cheat the protein assays by spiking melamine into the raw materials. Where vegetables are concerned, melamine is apparently a breakdown product of the approved pesticide cyromazine. Recent screening in China identified as much as 17mg/kg of melamine in batches of Chinese mushrooms. Apparently small amounts of melamine are already in our food chain, as a result of contaminated animal feeds etc.

It has been difficult for the regulatory authorities to pin down an acceptable concentration of melamine in food products. The FDA appear to have kind settled on 2.5mg/kg (not applicable to infant food products). Taiwan and Hong Kong use this benchmark as well, although some products have been voluntarily recalled even though levels were less than this arbitrary cut-off.

It is not clear what Singapore's standards are. A visit to the AVA website reveals little about what the permissable levels are. The prohibited products listed contain a minimum of 8.1 ppm (8.1mg/kg).

It is unfortunate that our AVA has not been as forthcoming as they ought to be about this matter. Press releases are few and far between. Important information is squirreled away on their obscure website. I tried, for example, to find out what products have been tested (I really want to know if my 3:1 coffee mix is safe or not!!)...but found no such listing. Does this mean that all other products are safe or that we actually don't know?

There are also some problems with respect to the information they provide....for example the cited TDI (Tolerable Daily Intake) published by the FDA is wrong. The AVA report cites a value of 0.63mg/kg melamine, or a total intake for a 60kg man of 37.8mg, whereas the FDA uses a value 0f 0.063 mg/kg of melamine plus analgues, or 3.78 mg for a 60kg man. This is 10x lower.

Also the measured amounts of melamine in the banned items are listed in ppm units....While this may be technically correct, it really makes no sense to the general public, particularly as acceptable limits etc are published as mg/kg?

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