Hurricane Sandy has come and gone from the East Coast, leaving behind a wide path of destruction that now presents a host of public health concerns to those affected. With power outages, flooded sewage-treatment plants, and contaminated floodwaters, millions of people face dangers from food, the water and the air.

Thomas Frieden, M.D., director of the Centers for Disease Control and Prevention (CDC), told National Public Radio (NPR) that people are at risk of food poisoning from eating food that has remained too long in warm refrigerators during the widespread power outage, which is what happened in New York in 2003 after a long blackout.

"We saw a significant increase in food-borne illnesses in the days after," Friedan said.

Floodwaters, however, present one of the most obvious health threats and can be harmful in multiple ways. Also interviewed by NPR, Tina Tan, state epidemiologist for the New Jersey Department of Public Health, said the water could become a mixture of toxic chemicals from the variety of pesticides, paint, and gasoline that people keep in their basements and garages.

In addition, sewage-treatment plants that have broken down due to fires or flooding can further contaminate floodwaters with various bacteria, viruses, and parasites, all of which can survive for months.

"That kind of shows up as nausea, vomiting, diarrhea and other symptoms related to gastrointestinal illnesses," Tan said

National Geographic Daily News states that the urban bacteria commonly known as E. Coliis the most concerning, which is easily spread by floods carrying raw sewage in high density areas, such as New York City.

Another danger lurking in the water includes downed wires that can electrocute people.

In preparation for the widespread power outages, people have used generators as a way to obtain power. The problem is, these generators need to be properly vented and are not meant to be used indoors. Dan Kass, the deputy commissioner for environmental health at the New York City Department of Health and Mental Hygiene, told NPR carbon monoxide is one of the most common killers after a big disaster.

In a Huffington Post story about the hurricane's affect on the health care system, Jerome Hauer, commissioner of the New York state Division of Homeland Security and Emergency Services, spoke of the decision to remove patients from area hospitals and several nursing homes. 

"You try to keep as many of these facilities open as possible as long as people are not in jeopardy," Hauer said. "These are always tough decisions."

An ABC News article noted issues at five nuclear plants affected by Hurricane Sandy, saying the nation's oldest nuclear plant had declared an alert and a second plant 40 miles from New York City was forced to shut down. However, there was no release of radioactivity, no damage to equipment or threat to public health, according to Entergy, the plant's operator.