Navigation Links
Study: Fish near coal-fired power plants have lower levels of mercury

A new study from North Carolina State University finds that fish located near coal-fired power plants have lower levels of mercury than fish that live much further away. The surprising finding appears to be linked to high levels of another chemical, selenium, found near such facilities, which unfortunately poses problems of its own.

"We found that fish in lakes located at least 30 kilometers (km) from a coal-fired power plant had mercury levels more than three times higher than fish of the same species in lakes that are within 10 km of a plant," says Dana Sackett, a Ph.D. student at NC State and the lead author of a paper describing the study. "This information will inform health and wildlife officials who make determinations about fish consumption advisories and wildlife management decisions."

The findings are surprising because coal-fired power plants are the leading source of mercury air emissions globally, and a significant amount of that mercury is expected to settle out of the air within 10 km of a plant's smokestacks. Mercury is a bioaccumulative toxin that builds up in animal tissues including fish and can pose public health problems related to fish consumption.

The researchers examined largemouth bass and bluegill from 14 freshwater lakes seven within 10 km of a plant and seven that were a minimum of 30 km from a plant. The species were chosen because they are commonly caught and eaten by recreational anglers, and because they represent two very different places in the food chain. Largemouth bass are apex predators at the top of the food chain, which consume smaller fish. As a result, since mercury builds up in the food chain, they would be expected to show higher levels of mercury. Bluegill are smaller fish that primarily dine on invertebrates, such as insects, and would be expected to show lower levels of mercury.

The researchers found that the mercury levels went up more than threefold in both species at lakes located further from the power plants, meaning that the location effect impacts fish regardless of their place in the food chain.

The researchers think that the lower mercury levels near power plants are likely linked to selenium levels. Fish tissue samples taken within 10 km of a coal-fired power plant showed selenium levels three times higher than samples taken from fish located further away. This shows an inverse relationship to the mercury levels the higher the selenium level, the lower the mercury level.

Selenium, which is also emitted by coal-fired plants, is known to have an antagonistic relationship to mercury, though the specific mechanisms at play are not clearly defined. In other words, the selenium prevents fish from accumulating high levels of mercury, and we're still working on the specifics of how that happens.

However, while lower mercury levels are a good thing, higher levels of selenium pose their own risks. "Selenium is an important dietary element," says Dr. Derek Aday, associate professor of biology at NC State and a co-author of the paper. "But at high levels, it can have serious consequences including lethal effects and an array of health problems for fish and wildlife."


Contact: Matt Shipman
North Carolina State University

Related biology news :

1. Study: urban black bears live fast, die young
2. Study: Bird diversity lessens human exposure to West Nile Virus
3. Study: Tropical wetlands hold more carbon than temperate marshes
4. Study: Wildlife need more complex travel plans
5. Study: Elderly Women can increase strength but still risk falls
6. UNC study: Text messaging may help children fight off obesity
7. Study: Did early climate impact divert a new glacial age?
8. Study: Excessive use of antiviral drugs could aid deadly flu
9. UNC study: Tinkering with the circadian clock can suppress cancer growth
10. Study: Fluid buildup in lungs is part of the damage done by the flu
11. Study: Health undervalued in reproductive rights debate
Post Your Comments:
Related Image:
Study: Fish near coal-fired power plants have lower levels of mercury
(Date:11/16/2015)... Nov 16, 2015  Synaptics Inc. (NASDAQ: ... solutions, today announced expansion of its TDDI product ... touch controller and display driver integration (TDDI) solutions ... These new TDDI products add to the previously-announced ... TD4302 (WQHD resolution), and TD4322 (FHD resolution) solutions. ...
(Date:11/10/2015)... , Nov. 10, 2015  In ... on the basis of product, type, application, ... included in this report are consumables, services, ... report are safety biomarkers, efficacy biomarkers, and ... this report are diagnostics development, drug discovery ...
(Date:11/2/2015)... , Nov. 2, 2015  SRI International has been ... provide preclinical development services to the National Cancer Institute ... will provide scientific expertise, modern testing and support facilities, ... preclinical pharmacology and toxicology studies to evaluate potential cancer ... The PREVENT Cancer Drug Development Program is an ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... -- Orexigen® Therapeutics, Inc. (Nasdaq: OREX ) today ... discussion at the Piper Jaffray 27th Annual Healthcare Conference ... is scheduled for Wednesday, December 2, at 8:00 a.m. ... will be available for 14 days after the event.  ... Corporate Communications and Business Development , BrewLife(858) 875-8629 ...
(Date:11/24/2015)... , Nov. 24, 2015 Cepheid (NASDAQ: ... speaking at the following conference, and invited investors to ... NY      Tuesday, December 1, 2015 at 11.00 ... NY      Tuesday, December 1, 2015 at 11.00 ... Conference, New York, NY      Tuesday, ...
(Date:11/24/2015)... , Nov. 24, 2015 /PRNewswire/ - Aeterna Zentaris ... of IIROC on behalf of the Toronto Stock Exchange, ... release there are no corporate developments that would cause ... --> --> About Aeterna ... . --> Aeterna Zentaris is a ...
(Date:11/24/2015)... SHPG ) announced today that Jeff Poulton , ... Annual Healthcare Conference in New York City ... (1:30 p.m. GMT). --> SHPG ) announced today that ... Piper Jaffray 27 th Annual Healthcare Conference in ... at 8:30 a.m. EST (1:30 p.m. GMT). --> Shire ...
Breaking Biology Technology: