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Notre Dame's Department of Civil Engineering and Geological Sciences

Cadmium is one of a group of potentially dangerous elements -- including arsenic -- that's been found in trace amounts in durum wheat, the variety used to make pasta. Wheat grown in Canada and the United States has been found to contain much higher concentrations of cadmium than wheat harvested in Argentina, Italy and other parts of the world, according to Jinesh C. Jain, an assistant professional specialist in the civil engineering and geological sciences department who is studying cadmium's movement into the food chain.

The likely reason, Jain says, is that North American farmers apply more phosphate-based fertilizer, which often contains small amounts of cadmium.

Cadmium is a heavy metal that accumulates in the body and has been tied to kidney disease and prostate cancer. In high enough concentrations, it can even be fatal.

The good news is that even the elevated levels of cadmium found in North American wheat aren't thought to be harmful, even if one ate pounds of spaghetti made from it daily.

That doesn't mean researchers aren't concerned, however. With additional cadmium getting into water and soils via industrial pollution and other sources, some health organizations worry that its concentration in the food chain could increase.

The best-documented case of cadmium food poisoning occurred in Japan in the 1950s, when more than 50 people were diagnosed with itaie-itaie, a disease that primarily affects the lungs, kidney and bones. Elevated levels of cadmium were found in rice they had eaten.

Cadmium also poses an economic danger. No standard has been established for safe levels of cadmium in food products. If one were set, however, North American wheat farmers might have to find ways to reduce levels in their crops or risk losing export markets, Jain says.

Scientists not only want to pinpoint where the cadmium in food is coming from but find ways to keep it from being taken up by plants. Jain's contribution to those efforts has been to measure precisely how much cadmium exists in wheat grown in different places.

To do that, the Notre Dame researcher uses a chemical analyzer employing a relatively new technology, Inductively Coupled Plasma Mass Spectrometry. The system is so sensitive it can detect the presence of every element on the periodic table down to one-billionth of a gram for most elements and one-trillionth of a gram for some. It scans for all the elements at once. Amazingly, the whole process takes only about a minute, he says.

The machine, which is kept in an ultra clean room equipped with special air filtering, for obvious reasons, can analyze any kind of material -- solid, liquid or gas. Among the more unusual materials Jain has analyzed are pieces of brain tissue taken from Alzheimer's patients.

Jain says one of the goals of his research is to find wheat that contains no cadmium. Seeds from the plants that produced such wheat would then be planted in soil containing cadmium to see if the element was taken up by the roots. Once plants are found that don't take up the element, scientists can genetically manipulate a new line of cadmium-resistant durum wheat.

-- Ed Cohen