Add environmental injustice to the costs of food-borne illness: It turns out that low-income shoppers are at greater risk of buying cucumbers, strawberries, and other produce tainted with bacteria, yeast, and mold.

The findings are part of a Drexel University pilot study, published in the May issue of the American Journal of Preventive Medicine.

The Drexel researchers tested foods from six markets in and around Philadelphia, Penn., over a 15-month period. They found that at markets serving lower-socio-economic-status populations (areas where more than 25% of the residents were below the poverty line), ready-to-eat greens and strawberries showed higher bacteria, yeast and mold contamination, and cucumbers higher yeast and mold counts, than the same produce in higher-income and status neighborhoods (areas where fewer than 3% lived below the poverty line).

"No signifıcant differences were found for microbial indicator counts for broccoli, watermelons, orange, juice, or milk," according to the researchers.

Why the difference? Are suppliers targeting the poor with older, crappier produce that they can't unload on the rich? As usual, it's not quite that simple.

The reason these moldy oldies are ending up in low-income nabes appears related to the long-known-and-fought problem of "urban food deserts": neighborhoods that have been abandoned by large supermarkets offering healthy food at an affordable price.

The generally-accepted definition of a food desert is that residents must travel twice as far to get to the nearest supermarket as their cohorts in better-off parts of a town.

Where would you shop for meat and produce once a week or more, if you had to travel twice as far to get to the nearest supermarket? Quite possibly, you'd do what many living in urban food deserts do: you'd shop at a smaller local market or convenience store, which might or might not make a point of handling produce carefully, if it carried produce at all.

"Conditions needed to maintain perishable foods safely and allow minimal growth of bacteria," write the Drexel team, "include proper refrigeration during transport and storage, protection from pests, and protection from excessive handling, which might introduce bacteria."

Small retail facilities that serve populations in low-SES urban areas may lack the resources, time, or knowledge to focus on sanitation and proper refrigeration. Small urban retailers may also rely on nontraditional transportation methods that are not refrigerated if they are located in small, inner-city streets. They may also be a captive market for less quality products from suppliers who have strict quality standards to meet for large corporate retailers.

Food deserts are such important factors in rates of obesity, diabetes, and other illnesses, that Michelle Obama has made access to healthy, affordably-priced groceries it a cornerstone of her "Let's Move!" campaign against childhood hunger and obesity.

Still, even if you live in a "food oasis," don't get complacent about the safety of your local food supply. In comparing rates of pathogens like salmonella and campylobacter in raw chicken, as well as E.coli, fecal coliforms and bacteria in ground beef, the Drexel researchers found that bacteria levels in ground beef were higher in high-socio-economic-status markets, although fecal coliform and E. coli levels were about the same in both income areas.

These findings suggest, they say, that these pathogens are being introduced "at the level of farm and production facilities," not at the retail end of the food supply chain.

Yum.

Image credit:http://www.flickr.com/photos/australianshepherds/ / CC BY 2.0