More rain is in the forecast for many flood-ravaged areas this week, but in areas where floodwaters have receded public health officials are warning people to not eat fruits and vegetables from backyard gardens or commercial growing fields that were under water.

“Gardens that were partially flooded may still be growing. Produce ripe for picking may look edible. However, any plants that came in contact with floodwater must be destroyed. It is a serious health concern,” cautioned West Virginia Commissioner of Agriculture Walt Helmick in a public warning in recent days. Floodwater carries pathogens such as E. coli, Salmonella and Listeria, according to the West Virginia notice and guidance from the U.S. Food and Drug Administration. Raw sewage, heavy metals and chemicals are also a concern. “Whenever those organisms come in contact with a food source, it becomes dangerous to consume,” Hemlick’s warning said. Numerous state health and agriculture websites, as well as extension offices at colleges and universities across the country, have posted warnings in recent days advising against trying to salvage vegetables or fruits from gardens or fields that were under floodwaters. Even root vegetables, such as potatoes and carrots, that are under ground should not be consumed if floodwaters covered the soil above them. Similarly, fresh produce such as squash and melons that have been touched by floodwaters should not be eaten, according to the FDA. Their thick rinds do not provide protection for the edible flesh inside. “There is no practical method of reconditioning the edible portion of a crop that will provide a reasonable assurance of human food safety,” according to the FDA’s posted guidance information about flooding and food safety. Any of the following foods that came into contact with floodwater should be discarded:

• Surface crops such as leafy greens, tomatoes, string beans, berries and sweet corn;
• Underground crops, such as peanuts, potatoes, carrots and garlic;
• Crops with a hard outer skin or shell, such as watermelon and winter squash; and
• Grains, nuts, corns and similar products stored in bulk.

Fruits and vegetables can “take up” contaminants in floodwater, distributing pathogens and other dangerous substances through the tissue and edible portions of the produce, according to Penn State’s Master Gardner Program website. “Even crops growing on stalks or vines above water levels can be tainted by splashing or infiltration,” according to the Penn State information. “Gardeners preparing an unplanted field or making soil that has been partially or completely flooded ready for replanting should treat the soil as if it has been treated with fresh manure: do not harvest or consume any produce grown in the field for 120 days.” As of Monday evening, the National Weather Service reported four states with major flooding ongoing — Louisiana, Mississippi, North Dakota and Oklahoma —  and minor flooding in seven other states. In Louisiana alone seven people have died and 20,000 have been rescued from the flooding. Sunday Gov. John Bel Edwards said the state had 10,000 people in temporary shelters because of the disaster. (To sign up for a free subscription to Food Safety News, click here.)