Featured Research

from universities, journals, and other organizations

Toxic Flood Lifts Lid On Common Urban Pollution Problem

Date:
September 20, 2005
Source:
University of Florida
Summary:
Broken sewers, flooded industrial plants and dead bodies are all likely to blame for poisoning the waters being drained from New Orleans. But the water – and the muck it is leaving behind — also owes its contamination to a source as mundane as it is unexpected: Toxins common in most urban environments that made their way en masse into the water as it stagnated atop the city.

Related Articles


But the water – and the muck it isleaving behind — also owes its contamination to a source as mundane asit is unexpected: Toxins common in most urban environments that madetheir way en masse into the water as it stagnated atop the city.

Sosays a University of Florida professor who has spent years studying theharmful contaminants that turn up in urban runoff, or rainwater thatwashes across streets and other hard surfaces in cities. Environmentalengineering professor John Sansalone’s perspective is especiallyrelevant because it is based on field research in New Orleans and BatonRouge, where he was a professor at Louisiana State University beforetaking a job at UF this summer.

“What we see in New Orleans isthat when you put a lot of water in contact with the urban environment,all the potential contaminants that stayed around in that environmentare now back in the water – definitely, to our horror,” Sansalone said.

Federaland Louisiana officials continue to sound alarms about the contaminatedwaters and scum left behind by the retreating flood. Early Septembertest results released late last week showed high levels of bacteria,lead and harmful levels of chemicals including arsenic, according tothe Environmental Protection Agency.

While the sources of theseand other contaminants remain under investigation, public scrutiny hasfocused on broken sewer pipes and other major failures in the city’sinfrastructure attributed to Hurricane Katrina. Though these arecertainly real problems, it’s also highly likely that the stagnantwaters are contaminated because they’ve soaked up “legacy” pollutantsthat accumulated during normal conditions on the city’s streets,sidewalks, roofs and other impermeable surfaces, Sansalone said.

Thesepollutants, which normally appear in urban runoff, are more toxic thancommonly understood, he said. In a study published last month in WaterEnvironment Research, Sansalone and three co-authors report that runofffrom an elevated section of Interstate 10 in Baton Rouge contained somecontaminants at levels “greater than those found in untreated municipalwastewater from the same service area,” according to the study.

Thefindings were based on periodic analysis of runoff that drains offInterstate 10 into Baton Rouge’s City Park Lake just below the highway.Based on data first gathered in 1999, they revealed high levels ofparticulates, or microscopic- to millimeter-sized particles ofmaterial, as well as high chemical oxygen demand, an indicator of thepresence of organic chemicals in oil, gas, grease, cigarette filtersand other pollution.

Other research on urban runoff, meanwhile,has detected high levels of toxic metals and nutrients includingphosphorus thought to leach from building materials, Sansalone said.

Organicchemicals are particularly dangerous to fish and other aquatic lifebecause they reduce the levels of oxygen in the water, impinging on itsability to support life. Particulates cloud water, reducing sunlightpenetration and plant growth. Once they cross a certain threshold,organic chemicals and metals also can be harmful to people.

NewOrleans officials remain extremely concerned about bacterialcontamination in the flood waters. Typically the result ofcontamination from untreated sewage, bacteria also can come from urbanrunoff, Sansalone said. Although it was not measured as part of hispublished study, other studies have found that such runoff containsheightened levels of bacteria stemming from bird and animal droppings,among other sources.

Sansalone said based on his studies of urbanrunoff alone, it’s critical that environmental officials scour the cityof flood residue. “How we clean up this residual matter – which willnot be easy – will be a chronic issue to the health of the city,” hesaid.

He said the contamination in New Orleans also highlightsthe need for other cities nationwide to do more to remove the toxins inurban runoff before, rather than after, it gets washed into waterways.There are several good strategies, he said. Increasingly affordable“permeable pavements” allow runoff to be stored, evaporate or percolatethrough pavement and into the ground, where soil and microorganisms canhelp filter the contaminants. Planting vegetation and especially treesalso creates aesthetically pleasing buffer zones, providing storm waterflooding control and other benefits. Finally, cities can use high-techstreet sweeping equipment that is very effective at capturing pavementcontaminants.

“If you pick up this potentially toxic materialbefore it gets into the hydrological cycle, it is far more economicalthan if you try to take it out of the water after the fact,” he said.


Story Source:

The above story is based on materials provided by University of Florida. Note: Materials may be edited for content and length.


Cite This Page:

University of Florida. "Toxic Flood Lifts Lid On Common Urban Pollution Problem." ScienceDaily. ScienceDaily, 20 September 2005. <www.sciencedaily.com/releases/2005/09/050920081636.htm>.
University of Florida. (2005, September 20). Toxic Flood Lifts Lid On Common Urban Pollution Problem. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2005/09/050920081636.htm
University of Florida. "Toxic Flood Lifts Lid On Common Urban Pollution Problem." ScienceDaily. www.sciencedaily.com/releases/2005/09/050920081636.htm (accessed October 24, 2014).

Share This



More Earth & Climate News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins