Wednesday, October 08, 2008 Speak out: Melamine and food safety By Romeo F. Quijano, MD College of Medicine, UP Manila
THE melamine poisoning issue is a symptom of a decadent global food system characterized mainly by corporate greed and government neglect.
Government tries to show it is doing something by parading to the media hurriedly confiscated milk products.
Yet it downplays the danger by echoing a familiar corporate whitewash: that people have to ingest unrealistically huge volume of contaminated milk to be poisoned.
Exposure to melamine and related chemicals, in fact, is not new.
Melamine is a triazine synthetic chemical used, usually with formaldehyde, in a range of products such as kitchen dishes and utensils, formica, laminate flooring, whiteboards, furniture,etc.
It is also a metabolite of cyromazine, a triazine pesticide commonly used in vegetable and chicken farms.
In 1987, melamine was demonstrated to be present in coffee, orange juice, fermented milk and lemon juice, originating from migration of melamine from the cup made of melamine-formaldehyde resin.
From 1979-1987, there was widespread melamine contamination of fish and meat meal in Italy and in 2004, there was nephrotoxicity outbreak in pets in Asia.
Again, in 2007, thousands of cats and dogs, mostly in the US, became seriously ill or died of acute renal failure after eating pet food contaminated with melamine and related triazine compounds such as ammelide, ammeline trichloromelamine and cyanuric acid.
Hogs, chicken and fish were also found to be contaminated with melamine and cyanuric acid.
Cyanuric acid is a common disinfectant used in swimming pools together with chlorine.
Trichloromelamine is the chlorinated form of melamine and is mainly used as disinfectant and cleaning agent.
Melamine may cause adverse reproductive effects, may affect genetic material and may cause bladder cancer based on animal data.
It may also cause skin, eye and respiratory tract irritation and irritation of the digestive tract with nausea, vomiting and diarrhea, and may damage the urinary system.
By themselves, melamine and cyanuric acid are considered to be of low acute toxicity by regulatory agencies based on standard risk assessments for each chemical.
It is from this limited risk assessments that official tolerance levels (e.g., “15 cups of milk per day for several months”) are derived.
However, multiple source and multiple chemical exposures, including exposure to both melamine and cyanuric acid (which has been found to be much more toxic in combination), is the more likely exposure situation and this should be the basis for assessing risks to human health.
Despite the limited scientific data and the low acute toxicity attributed to melamine and related triazine compounds, much can be said about the potential harm that these chemicals pose to animals and human beings.
The mechanism of renal toxicity of melamine and cyanuric acid is well established and that acute or chronic exposure would likely result in adverse renal toxicity that could lead to renal failure.
Existing empirical and scientific data indicate that exposure levels sufficient to cause harm are likely to be reached under present circumstances.
In fact, the European Food Safety Authority, despite using the conservative risk assessment methodology, came up with this statement, “in worst case scenarios with the highest level of contamination, children with high daily consumption of milk toffee, chocolate or biscuits containing high levels of milk powder would exceed the TDI (tolerable daily intake).”
This assessment did not consider potential additional exposures likely to occur in developing countries, such as, cyanuric acid in swimming pools, melamine from the pesticide cyromazine and in contaminated vegetables, fish and meat, and melamine leachate in kitchen wares.
The extent of harm that melamine and related compounds have caused is not clear at this time but the problem is not just melamine and simply confiscating products will not solve the problem.
Government officials should not downplay the dangers of toxic chemicals contaminating food.
Mechanisms for appropriate monitoring and timely intervention should be established.
Food safety should be placed high in the political agenda and greed, corporate and otherwise, eliminated.
Safe food should be put in the hands of the people!
