If the burger doesn't get hot enough, all kinds of critters can survive the cooking. So what's a body to do? The folks at the Department of Agriculture tell us the best defense is to push a thermometer into that burger and make sure it's at least 160 degrees before pulling it off the grill. Or 170 degrees for chicken breasts. Or 145 degrees for beef steaks, veal and lamb, and 160 degrees for all kinds of pork.
So there you are, armed with a thermometer to make sure you get that burger hot enough, but not too hot so that all those carcinogens form, as Smith warns.
If all this makes him sound like a party pooper, rest assured that Smith is a dedicated barbecue fan himself.
"You do get some benefits from barbecuing," he says.
For example, we've all heard that smoke is bad, and too much of it clearly is, but a little smoke coming from the barbecue is actually a good thing.
"Some of the smoke actually contains phenolic compounds, and those are antioxidants," he says. "Some are very potent antioxidants and they get coated on the surface of the product," be it meat, fish or fowl.
"I'm not knocking barbecuing," he says. "I do it all the time."
In time, he hopes, the non-volatile extracts from the spices he is studying might be available in grocery stores. That way we could make our burgers safer without having them taste and smell like rosemary.
Lee Dye's column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.