Earth Science News  





. Dartmouth Researchers Alarmed By Levels Of Mercury And Arsenic In Chinese Freshwater Ecosystem

Lake Baiyangdian. Photo courtesy AFP.
by Staff Writers
Hanover NH (SPX) Jan 10, 2008
A team of researchers, led by biologists at Dartmouth, has found potentially dangerous levels of mercury and arsenic in Lake Baiyangdian, the largest lake in the North China Plain and a source of both food and drinking water for the people who live around it.

The researchers studied three separate locations in Lake Baiyangdian, all at varying distances from major sources of pollution, such as coal emissions, agricultural runoff, and sewage discharge. They found concentrations of arsenic and mercury in fish were above the threshold considered by the U.S. Environmental Protection Agency (EPA) to pose a risk to humans and wildlife.

The findings were published online on Dec. 24, 2007, in the journal Water, Air, and Soil Pollution.

"It's important to study this system because it is typical of many throughout China where human activity and industrialization are having detrimental effects on the environment with major human health implications," says Celia Chen '78, a research associate professor of biological sciences. "It makes perfect sense to apply what we're learning about lakes in the U.S. to other places in the world, like China, that have a growing global impact."

Chen and her team were curious to learn how arsenic and mercury, two toxic environmental metals, moved through the food web in a freshwater ecosystem known to be polluted and contaminated. In a process called bioaccumulation, mercury and arsenic were found throughout the food web, from the water, into the algae, through the tiny algae-eating zooplankton, to the fish. As expected, the researchers found that more nutrient-rich environments supported larger algal blooms, which resulted in lower concentrations of mercury and arsenic in the water due to uptake by the algae.

In their previous work, the researchers found that when there is a lot of algae present, mercury and arsenic are biodiluted, or more dispersed, so zooplankton that eat the algae are exposed to lower levels of the metals and transfer less to fish.

"Despite this potential interaction - a decrease in bioaccumulation due to high algal biomass - the mercury and arsenic in this system are high enough to be of concern to humans and wildlife that drink the water and consume fish," says Chen. "For example, we saw arsenic levels in the water that represent more than fifty times the EPA-recommended limit for consumption of fish and shellfish."

Chen's co-authors include Carol Folt, dean of the faculty and professor of biological sciences at Dartmouth, Paul Pickhardt at Lakeland College, and M.Q. Xu at the Chinese Academy of Sciences in Beijing. Chen and Folt are both affiliated with Dartmouth's Center for Environmental Health Sciences and its Toxic Metals Research Program. Funding from the National Science Foundation and the National Institute of Environmental Health Sciences supported this work.

Community
Email This Article
Comment On This Article

Related Links
Dartmouth
Our Polluted World and Cleaning It Up




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Mafia at centre of Naples' rubbish mess
Naples, Italy (AFP) Jan 9, 2008
Many Naples residents sum up the region's recurring waste disposal nightmare in one word -- the mafia -- but organised crime is only part of the conundrum.

.
Get Our Free Newsletters Via Email
  



  • WHO Says Only 151 000 Iraqis Died From Violence Since 2003 Invasion
  • Indonesian landslide, floods toll at 107 dead: health ministry
  • New Indonesia landslide as search for victims continues
  • Natural catastrophes will grow with climate change: re-insurer

  • Japan temperatures could rise five degrees by 2100: panel
  • Electric Sand Findings Could Lead To Better Climate Models
  • Australian climate changing, experts say
  • North Atlantic Warming Tied To Natural Variability; But Global Warming May Be At Play Elsewhere

  • Japanese satellite flops at map-making: official
  • SERVIR: NASA Lends A Hand In Central America
  • ISRO To Launch Carto-2A Satellite In January 2008
  • Outside View: Arctic satellite balance

  • Sustainable Fuel For Road, Rail, Air And Sea Transport
  • China poised to be world leader in renewable energy, expert predicts
  • Analysis: Crunch time for Bolivian gas
  • Northrop Grumman Wins Orders To Upgrade Navigation Systems For Shell Liquefied Natural Gas Carriers

  • Building boom drives rapid AIDS spread in Indonesia: ADB
  • MIT Finds Key To Avian Flu In Humans
  • China reports good progress in human bird flu vaccine
  • Sea cucumber protein used to fight malaria

  • 480-Million-Year-Old Fossil Sheds Light On 150-Year-Old Paleontological Mystery
  • Humans Have Caused Profound Changes In Caribbean Coral Reefs
  • Elephants outsmarting humans on Indonesia's Sumatra: report
  • It's raining iguanas after Florida cold snap

  • Mafia at centre of Naples' rubbish mess
  • Dartmouth Researchers Alarmed By Levels Of Mercury And Arsenic In Chinese Freshwater Ecosystem
  • Italian troops to help dig Naples out of rubbish crisis
  • Plan to end Naples rubbish crisis wins cautious welcome

  • New Book Reveals An Evolutionary Journey Of The Human Body
  • US braces for baby boom retirement wave
  • Evolution Tied To Earth Movement
  • Monkeys Can Perform Mental Addition

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement