Tonight, special correspondent Rick Karr looks at environmental concerns in New York City. Many residents in Brooklyn want to know more about the risks of chemicals that may have spread when the storm surge hit.

　　RICK KARR:The area around Brooklyn's GowanusCanal could be New York City's answer to Amsterdam. At least, that's what some real estate developers are betting. The canal's neighbor to the north, Newtown Creek, can offer up its own beautiful vistas, but both waterways are also surrounded by heavy industry, as they have been for more than a hundred years.

　　And so they're among the most polluted in the country, so bad that the Environmental Protection Agency has designated both as superfund cleanup sites.

　　THOMAS BURKE, JohnsHopkinsUniversity: There are persistent contaminants there, like PCBs, like heavy metals, that have been there probably for a good part of the last century.

　　RICK KARR:Thomas Burke teaches about the environment and public health at JohnsHopkinsUniversity.

　　THOMAS BURKE:There are also kind of combustion byproducts—that sounds like a fancy term, but that's from the old plants there, coal tar plants and plants like that, so there's heavy petroleum molecules too.

　　RICK KARR:Some of those chemicals in the water have been shown to cause cancer in animals. Others can damage the central nervous system. Both the creek and the canal overtopped their banks when Sandy's storm surge reached them. The water lapped onto sidewalks and poured into buildings nearby.

　　Here in the Greenpoint neighborhood, the Newtown creek is less than a quarter-mile away. And one of New York's biggest sewage treatment plants, which was also in the flood zone, is just around the corner. Resident Jacqueline Lombard says water poured into her house from both directions.

　　JACQUELINE LOMBARD,New York resident: The evening that Sandy hit, we were hit with an eight-foot storm surge that basically flooded my basement up through the ceiling and my landlord's basement here up through their first floor. So it was a very smelly, noxious mix.

　　RICK KARR:The floodwaters drained out of Lombard's basement quickly, but left a lot of muck behind.

　　JACQUELINE LOMBARD:There was a lot of silt, a lot of mud, a lot of debris, sewage that flowed in and then flowed out. And the residue was left.+RICK KARR:The flood left residue in Emrys Berkowers' waterfront furniture workshop too.

　　EMRYS BERKOWERS,New York resident: There was an oily sheen, a slippery feel to everything. I saw a good number of things that had a sort of white foamy, kind of almost waxy film. I really don't know what it is. And it's kind of alarming to me, actually.

　　RICK KARR:Berkowers' workshop sits around three quarters of a mile from the mouth of the polluted GowanusCanal and this oil distribution depot.

　　REP. NYDIA VELAZQUEZ,D-N.Y.: We don't know what was in that water.

　　RICK KARR:Nydia Velazquez is a Democratic member of Congress who represents areas around the GowanusCanal and Newtown Creek. She's been pushing the Obama administration to find out what kinds of contaminants may have been spread by the storm and what can be done to prevent contamination during future floods.

　　NYDIA VELAZQUEZ: We have a cluster of heavy industries throughout the waterfront with some kind of metals, petroleum. We need to know if there are any safety and health issues as it relates to this storm surge that impacted these communities.

　　RICK KARR:The Environmental Protection Agency did test a few flooded sites, two along the GowanusCanal and two near the Newtown Creek. The agency tested the Newtown creek sites 13 days after the storm.

　　The EPA detected high levels of bacteria and some gasoline and diesel fuel. The agency declined requests for an interview, but in a press release reported that other chemicals that were tested were below levels of concern or not detected.

　　Thomas Burke of Johns Hopkins used to be the state of New Jersey's chief environmental scientist. He says it appears the risk from Sandy's floodwaters are low, but it's impossible to know the long-term risks of what may have been in the water without more extensive testing.

　　THOMAS BURKE:Does every single house have to be sampled? Can we characterize what was in the floodwaters without doing that? Probably. But we do need more samples. And I think, if I lived there, I would want to know.

　　RICK KARR:Burke says it's difficult for the EPA to do a lot testing in the wake of disasters like Sandy, but he says testing is the only way to ameliorate the fears of flood zone residents like Jacqueline Lombard.

　　JACQUELINE LOMBARD: I ended up in the hospital with a full-blown case of bronchitis. Eight days after, so did my landlord, so did his wife. So did our neighbor.

　　Everybody sort of got sick at the same time. All of us sort of attributed it to, well, we're all stressed out. It's very cold. We're all sleeping in houses without heat or hot water.

　　But, that said, you know, there is a lot of nasty stuff hanging about. And, you know, again, when the EPA shows up with a van and six people get out, you know, it kind of tells you something.

　　RICK KARR:Lombard says she's lucky. Because she was renting, she can move elsewhere. But her neighbors near the Newtown Creek's Superfund site may have to live through another flood and whatever it brings with it.