Cows that consume feed, grass or water contaminated with radioactive iodine-131 can concentrate the element in their milk. Peter Elvidge/iStockphoto.com hide caption

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Red #40, Blue #1, Yellow #6 - a rainbow of food dyes. Josh Roulston/Flickr hide caption

itoggle caption Josh Roulston/Flickr

Ultrasound scan of twins at 4 months. Getty Images hide caption

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Moshe Rute smokes marijuana at the Hadarim nursing home in Kibutz Naan, Israel, in early March. The Israeli government and a private company are distributing cannabis for medicinal purposes to more than 1,800 people in Israel. Uriel Sinai/Getty Images hide caption

itoggle caption Uriel Sinai/Getty Images