The great Mississippi River flood of 2011, cresting south of Memphis today, carries a mix of fertilizer, oil, pesticides, trash and farm runoff as it flows toward the Gulf of Mexico, say public health officials.
Some of it is nasty stuff, and officials say people are wise to be careful.
They urge people not to touch the water unless they're wearing rubber boots and gloves, and wash thoroughly if they get wet.
"There could be a lot of untreated sewage coming downstream," said Wilma Subra, an environmental scientist and activist in Louisiana who has tangled with oil and chemical companies. "People need to be aware."
