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.
Sue Knapp | EurekAlert!
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences