John Clark pours raw milk into a glass at Applecheek Farm in Hyde Park, Vt. Toby Talbot/AP hide caption

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Oranges for sale at a market in Rio de Janeirol. Antonio Scorza/AFP/Getty Images hide caption

itoggle caption Antonio Scorza/AFP/Getty Images

Irradiation is most often used to kill insects, parasites, or bacteria in or on spices, which are typically dried outdoors in before being shipped. Lui Kit Wong/MCT /Landov hide caption

itoggle caption Lui Kit Wong/MCT /Landov

Adrian Mesa protests the overuse of antibiotics in meat production outside a Burger King in Coral Gables, Fla. in 2003. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images