Melamine poisoning tip of the iceberg

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!

Romeo F Quijano, MD. Professor, Department of Pharmacology and Toxicology, College of Medicine,
University of the Philippines, Manila.

Chemical Cocktail 14(1); September 2008 ASEHA QLD Inc

MELAMINE POISONING ‘TIP OF THE ICEBERG’

Like many similar incidents in the past, the melamine poisoning scandal is just a symptom of a decadent global food system, characterised mainly by corporate greed and government neglect. The government ridiculously tries to show it is doing something to address the problem by parading to the media hurriedly confiscated milk products, yet at the same time, it downplays the dangers by echoing a familiar corporate whitewash that humans will have to ingest unrealistically high volumes of contaminated milk to be poisoned. Just as quickly, Nestle and other companies put out expensive adverts proclaiming that their products are safe, even without undergoing the appropriate tests. These short-sighted and self-serving knee-jerk reactions do not protect the health of consumers but perpetuate the pathetic state of affairs as far as food safety is concerned.

Food safety has never been a serious concern of governments and corporations, particularly with the advent of corporate globalisation. World Trade Organisation (WTO) provisions related to food safety
clearly subordinate protection of health and environment to corporate interests. Countries, especially the weaker countries, are forced to import food products contaminated with toxic chemicals or substances.

Any attempt to ban or restrict such harmful substances, even those already banned in other countries, is met with fierce resistance by corporate giants and their host countries. Such is the case e.g. artificial sweeteners and additives, GMOs and now melamine.

Exposure to melamine and related chemicals, in fact, is not new. Melamine is a triazine synthetic chemical usually used with formaldehyde, in a wide range of products such as kitchen dishes and
utensils, formica, laminate flooring, whiteboards, furniture, cleaning agents, fabrics, glues, colorants, flame retardants, fertilisers and drugs. Melamine 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 a nephrotoxicity (kidney disease) outbreak in pets in Asia. Again, in 2007, thousands of cats and dogs, mostly in the USA, became seriously ill or died of acute renal failure after eating pet food contaminated with melamine or 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. Cyanuric acid was used as an ingredient in herbicides and is also used in the production of the bacterial degradation of melamine and in the production of chlorinated bleaches and whitening agents. Trichloromelamine is the chlorinated form of melamine and is mainly used as disinfectant and as a 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 diarrhoea, and may damage the urinary system. Cyanuric acid and trichloromelamine have pretty much the same spectrum of toxicity as melamine. However, cyanuric acid and trichloromelamine have the greater toxicity potential, particularly, in causing kidney damage, developmental toxicity and cancer.

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 assessment that official tolerance levels are derived. However, multiple source and multiple chemical exposures, ncluding 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. Other important triazine compounds must also be considered in the assessment of risks.

For example, the triazine herbicides exemplified by atrazine are structurally similar to melamine and cyanuric acid. These herbicides are known to cause neuroendocrine and endocrine-related
developmental, reproductive and carcinogenic effects.

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 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 the statement, “in worse 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. Since milk and milk products from China were already banned in Europe at the time of the assessment, the worst case scenario for European children did not even consider potential sources from milk and ice cream!

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!

– Romeo F Quijano, MD. Professor, Department of Pharmacology and Toxicology, College of Medicine,
University of the Philippines, Manila.