Q: We’re all told not to drink the water in Mexico, but how are crops imported from Mexico safe if they are irrigated with the water we are told not to drink? I refused to buy a cucumber from Mexico for this reason. — Bea Bunten

A: With the recent salmonella outbreak linked to peanut butter, we all may be a bit wary of where our food comes from these days, and how it’s grown and processed.

In terms of food from Mexico, or from any other country that’s sold here, the U.S. Food and Drug Administration said it must be grown according to the same safety standards as domestically produced food.

Trevor Suslow, a specialist in produce safety, quality and pathology at the University of California, Davis, said many Mexican growers producing for expert do have access to clean water, either from deep aquifers or water sources that have been filtered and treated.

Water sources used for agricultural irrigation in Mexico are increasingly subject to testing, he said, and those testing programs are subject to third-party and Mexican-government audits. And certain products, such as canteloupe, must follow a specific food safety program that must be reviewed and approved by the U.S. FDA before it can enter the United States.

Something else to consider, Suslow said, is that bacteria, pathogens and other contaminants in water may have different potential impacts depending on how we’re exposed to them.

“Minor levels of contaminants in drinking water may be serious for an individual (if ingested) but the same water applied to crops may not result in survival (of the contaminant) on the crop,” Suslow wrote in an e-mail.

And, as the peanut butter recalls demonstrate, food-borne illness comes from domestically produced food, too — even from our own backyard.

Just last year, state officials traced an E. coli outbreak in the Midwest in 2006 to lettuce grown in Kern County. The investigation found that the strain of E. coli identified in the lettuce outbreak matched bacteria samples taken from the irrigation system delivering water to the lettuce field and a dairy next door.

So how do you balance food safety concerns without swearing off fruits and vegetables? 

“The bottom line for me and my family is we recognize there is a very small but real risk of food-borne illness from consumption of uncooked fruits and vegetables,” Suslow said. “However, the benefits of a diet that includes diverse fruits and vegetables, cooked and non-cooked, are the overriding factor in my own decisions to purchase these items year-round.

“... I have to put my own faith in the evolving food safety standards and the response of various government, non-governmental organizations and industry association groups to correct the problems we have experienced in the recent years.”

The FDA provides the following tips to reduce the risk of food-borne illness:

• Choose fruits and vegetable that aren’t bruised or damaged.

• Only buy bagged salad greens or pre-cut produce — such as half a watermelon or sliced carrots — that are refrigerated or surrounded by ice.

• Don’t put fruits and vegetables in the same bag as meat, poultry or seafood.

• All produce should be thoroughly washed just with water before eating, even if you plan to peel it.

• Using soap or commercial produce washes is not recommended.

• Firm fruits and vegetables, like melon and cucumbers, should be scrubbed with a brush.

• Wiping produce dry with a towel or paper cloth can further reduce any bacteria that may be present.

— Staff writer Stacey Shepard