The Washington-based Centers for Science in the Public Interest tracked data from 1990 and 2006 and revealed which foods caused the most food-poisoning outbreaks during that period.

1.  Leafy greens, 363 outbreaks. Greens were found to contain various pathogens, including E. coli, norovirus, and salmonella. They often can become contaminated during harvesting or during the pre-washing process for bagged lettuce.

2.  Eggs, 325 outbreaks. Most of the outbreaks were from salmonella due to improper handling and cooking. Restaurants were the worst offenders, serving eggs too raw or leaving them too long on buffet tables.

3.  Tuna, 268 outbreaks. The primary culprit is something called Scombroid poisoning, a toxin released when fresh fish is stored above 60 degrees F. It can cause headaches, cramps, nausea, diarrhea, palpitations, and loss of vision.

4.  Oysters, 132 outbreaks. Norovirus is common in tainted oysters and usually comes from the waters in which these delicacies are harvested. A bacterium called Vibrio is also present in oysters and it can infect the bloodstream and be life-threatening.

5.  Potatoes, 108 outbreaks. Outbreaks occur most frequently from contaminated or improperly refrigerated potato salad. The most common cause of potato-linked illnesses comes from E. coli and salmonella.

6.  Cheese, 83 outbreaks. Salmonella is the most common cheese hazard. Although most cheese is made with pasteurized milk, California officials have warned that many Latin-American-style cheeses may be made by unlicensed manufacturers using milk that could contain harmful bacteria. Pregnant woman should be cautious about eating soft cheeses like Brie or Camembert, which can carry Listeria. Listeria can cause miscarriage, say experts.

7.  Ice cream, 75 outbreaks. Salmonella and staphylococcus, most often from raw eggs in homemade ice creams, were the biggest threat.

8.  Tomatoes, 31 outbreaks. Tomatoes were implicated in four multistate outbreaks of salmonella. Restaurants were responsible for 70 percent of tomato-related illnesses.

9.  Sprouts, 31 outbreaks. Sprout seeds can become contaminated with salmonella or E. Coli during storage. Because sprouts pose a contamination hazard, the FDA recommends that people with compromised immune systems, the elderly, and the very young, do not consume raw sprouts.

10.  Berries, 25 outbreaks. Berries can be contaminated with hepatitis A or Cyclospora. In 1997, more than 2.6 million pounds of contaminated strawberries were recalled across several states when students became ill with hepatitis A, possibly from an infected farm worker.