Excerpt from article:

BOGOTA, Colombia -- It's probably the last thing most people think about when buying roses: By the time the bright, velvety flowers reach your valentine, they will have been sprayed, rinsed and dipped in a battery of potentially lethal chemicals.

Most of the toxic assault takes place in the waterlogged savanna surrounding the capital of Colombia, the world's second-largest cut-flower producer after the Netherlands. It produces 62 percent of all flowers sold in the United States...