How Pervasive Is Melamine In The US Food Supply?

It's time to check.

James E. McWilliams, writing in an Op-Ed piece for the New York Times yesterday:
Our Home-Grown Melamine Problem

... says China probably isn't the only country whose food supply is awash in melamine. The US food supply may also be contaminated.

Some of his points are debatable, but one I think is spot-on involves the dose-response relationship. Where a few acute doses of melamine might lead to kidney failure, what effect exists from small doses ingested over a long period of time? Because, without a doubt, there is melamine in our food.¹

One of the commenters, Elena P. from Seattle, WA shares my concerns:

"One health effect of melamine is kidney stones.

Not too long ago, I read an article about rising rates of kidney stones among children and young adults.² In the past, these groups have been considered low risk for kidney stones, but the article suggested this may be changing.

After reading this article, I wonder if there's any connection. Maybe not, but still, it's an interesting observation. Checking the food supply for possible melamine contamination might be a good place to start."

________¹ Besides Chinese milk and eggs, and products made from them such as candy (the Cadbury's Hazelnut Chocolate shown was found to contain melamine at levels 25 times Hong Kong's legal limit of 2.5 ppm), melamine has been found in ammonium bicarbonate, a leavening agent (contaminating 18 types of biscuits in Malasia), and in frozen green peas imported from China. China is one of the world's leading food exporters.
² Perhaps this one: A Rise in Kidney Stones Is Seen in U.S. Children