A clampdown on contamination in growing fields has pushed out wildlife and destroyed habitats. Adam Cole/NPR hide caption

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The U.S. Centers for Disease Control and Prevention cautions that unpasteurized milk can cause serious illness, because it's a fertile breeding ground for harmful germs like salmonella and E. coli. But such warnings haven't deterred raw milk enthusiasts. Abby Wendle/Harvest Public Media hide caption

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Charlotte Smith, of Champoeg Creamery in St. Paul, Ore., says raw milk may offer health benefits. But she also acknowledges its very real dangers. Courtesy of Champoeg Creamery hide caption

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The plate on the left contains about equal numbers of colonies of two different bacteria. After the bacteria compete and evolve, the lighter ones have taken the lead in the plate on the right. Courtesy of Michael Wiser hide caption

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Farmworkers like these in California picking produce may soon be required by the FDA to take more precautions against spreading foodborne illness. Heather Craig/iStockphoto.com hide caption

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Spinach has lots of opportunities to pick up E. coli and other bugs during harvest and growing. Here, a Mexican migrant worker cuts organic spinach during the fall harvest at Grant Family Farms in Wellington, Co. John Moore/Getty Images hide caption

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Red clover sprouts are pretty, but they and other sprouts have been linked to too much foodborne illness for major grocers to continue carrying them. Stephanie Phillips/iStockphoto.com hide caption

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Fenugreek sprouts like these may be the launching pad for recent outbreaks of illness from E. coli in Europe. Sriram Bala/Flickr hide caption

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Reinhard Burger, president of the Robert Koch Institute, tells reporters in Berlin Friday that sprouts from a German farm are the cause of the country's massive foodborne illness outbreak. Michele Tantussi/AP hide caption

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A closeup view of the bacterium behind the foodborne disease outbreak centered in Germany. Manfred Rohde/Getty Images hide caption

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Greenhouses of the shuttered Gaertnerhof Bienenbuettel organic farm in Bienenbuettel, Germany. Health authorities in the German state of Lower Saxony closed the farm over worries that the vegetable sprouts grown there could be a source of E. coli outbreak that has infected more than 2,300 people. But preliminary tests came back negative. Joern Pollex/Getty Images hide caption

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