Posted tagged ‘toxicology’

Melamine is here

November 26, 2008

Melamine in infant formula, here in the USA?

Yup. Trace amounts of this, as well as many other industrial chemicals, are found throughout the food chain. Plasticizers, solvents, cleaners, all sorts of chemicals are used in the processing and packaging of food. And shortly, you’re going to hear all sorts of grandstanding by politicians eager to make a splash in the news. But before you get caught up in the coming hysteria, let’s hear the rest of the story…

Melamine is an industrial product used in cleaning food equipment and packaging. It can also be used deliberately by ruthless food manufacturers to “fool” chemical assays of protein content—that’s probably why it was added in large amounts to several sources of milk used to make infant formula and other foods in China. That story broke in August, 2008, shortly after the Olympics. To date, the Chinese government has acknowledged 3 deaths and 50,000 sickened children from exposure to melamine, though many observers think the totals could be far higher. Melamine causes illness by binding with other chemicals in the urine and forming kidney stones. The tainted products were also exported from China to several neighboring countries, though very little was brought to the United States (only a few candies and novelty foods, mostly sold in Chinese markets, have been shown to be contaminated in high concentrations from the Chinese milk.)

Formulas and other foods in China that made babies ill have been found to have 2,500 parts per million (ppm) of melamine. Keep that number in mind.

In the United States, regulations prohibit the use of melamine as a food additive, but do allow melamine-containing solutions to be used as cleaners of food processing equipment (that regulation was passed over 40 years ago.) The FDA has established a “safe concentration” for most foods of less than 2.5 ppm, 1000x less than the toxic levels seen in China. However, this “safe concentration” does not apply to infant formula—for formulas, no “lower safe limit” has ever been established.

The commercial assays available for manufacturers to test for melamine have a lower detection limit of 0.25 ppm. This includes the published method that the FDA suggests food manufacturers use to test their own products. However, chemical methods continue to improve, and lower limits of detection have become possible with new technology.

The FDA began testing infant formula shortly after the melamine story broke, using the most sensitive assays available. They’ve found that several infant formulas in the US have measurable concentrations of melamine, about 0.14 ppm. It’s not known (or least I couldn’t find) assays of the concentration of melamine in breast milk or drinking water—but my guess is that it will be more than zero.

This concentration in formula is far less than the established safety threshold for most foods, and far far far less than the concentration that has made kids sick in China. Only a few years ago, this concentration wouldn’t even have been detectable; it’s only improved chemistry that has allowed us to know it’s even there.

Paracelsus (1493-1541), a Swiss chemist, is often credited for his statement of the most basic tenet in toxicology: “The dose makes the poison.” In other words, any substance is a poison at a high enough dose (for example, water, salt, and vitamin C will all kill you if you ingest enough of these.) And there is no substance that is poisonous if taken at a low enough dose. Even deadly rattlesnake poison or the most lethal nerve gases have a threshold of toxicity, below which they’re harmless.

Several politicians have already seized on the melamine issue, insisting on a “zero-tolerance” policy. From a science point of view, that’s silly: ordinary foods always contain traces of deadly chemicals, including arsenic (a natural element) and cyanide (which is produced in small amounts in each one of your body’s cells every day.) As chemical assays improve, it becomes possible to detect the most minute amounts of anything—does that mean that the small amounts, which may always have been present, pose a danger? And if all of the infant formula is recalled, what, exactly, are we supposed to feed our babies once they’ve weaned?

The harm of a mass recall of formula—babies being fed some kind of home-brew concoction, or products that are very demonstrably unsafe for infants (like plain whole cow’s milk)—is far, far greater than any harm that might be posed by these infinitesimal amounts of melamine. Besides, there’s an even higher amount of melamine allowed in whatever parents might use as formula substitutes. That couldn’t be an improvement.

The melamine issue requires some clear thinking. Formula manufacturers should work to find the source of the minimal contamination—probably a cleaning solution that could be rinsed more thoroughly—and eliminate that source. Studies to look for possible long-term effects of food-source melamine should be undertaken, and reasonable steps to minimize contamination with melamine and other chemicals should be taken at every step of food processing and preparation. But there is no reason for any sort of formula recall, and no reason for anyone to panic.