This release can be found in the USGS Newsroom at: http://www.usgs.gov/newsroom/article.asp?ID=2349.
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From Toxic Dust and Algae to Ill Winds From Africa
USGS at the Society of Environmental
Toxicology and Chemistry
Note to editors: The SETAC conference will be held in New Orleans from
Nov. 19-23. For more info on the conference, visit their Web
site.
Toxic dust: Toxins in coal-tar-based sealcoats in parking lots may
be the culprit in contaminated house dust, according to a USGS study. PAHs
– or polycyclic aromatic hydrocarbons – are large molecules found in
oil, coal and tar deposits, and can have toxic effects. It’s long been
known that PAHs are often found in house dust; however, the specific sources
of these PAHs are largely undetermined. Researchers found that dust from
indoor areas near parking lots with coal-tar-based sealcoat had substantially
elevated concentrations of PAHs. This study, PAHs in house dust and
relation to coal-tar-based pavement sealcoat, will be presented on
Nov. 20 at 10:20 a.m. in the Belle Chasse Room. For more information, contact
Barbara Mahler at bjmahler@xxxxxxxx
or at 512-927-3566.
Eensy-weensy spiders play large role as sentinels of contaminants: Spiders
that live near water may be an effective warning system for contaminants
in aquatic ecosystems, according to a new USGS and U.S. Environmental Protection
Agency study. Scientists examined PCB (polychlorinated biphenyls) levels
in shoreline-living spiders at Lake Hartwell, a Superfund site in South
Carolina, and used this information to map contaminant concentrations in
lake sediment. Future monitoring studies will use the spiders as indicators
of ecosystem recovery from PCB contamination. Researchers also made risk
maps for a spider-eating bird, the Carolina wren, which could be exposed
to PCBs through eating spiders. These spiders rely heavily on adult aquatic
insects for food and play a key ecological role in the transfer of contaminants
between water and land ecosystems. In spite of this, they are underused
as a sentinel species at contaminated sediment sites. This study, using
riparian spiders as sentinels of PCB export and risk, will be presented
on Nov. 21 at 3:50 p.m. in the Versailles Room. To learn more, contact
David Walters at waltersd@xxxxxxxx
or at 970-226-9484.
It’s an ill wind that blows: African dust making it across the ocean:
Increasing quantities of African dust have blown across the Atlantic
Ocean to the Caribbean and Americas over the past few decades. During that
time, the dust’s composition has changed. In this study, African dust
air masses in Africa and the Caribbean were analyzed for persistent organic
contaminants and metals. These potentially toxic contaminants can
originate from the burning of plastics, biomass and waste; widespread use
of pesticides, plastics, and pharmaceuticals; and increased industrialization.
Multiple pesticides and other contaminants, including carcinogens, suppressors
of immune systems, disruptors of endocrine systems, and nervous system
or liver toxins were identified from all sample sites. All are known
to persist in the environment, accumulate in organisms, and are toxic at
very low concentrations. This study, Chasing clouds of dust: transoceanic
transport of synthetic organic pollutants and trace metals with African
dust, will be presented on Nov. 22 at 11 a.m. in Ballroom D. For more
information, contact Ginger Garrison at ginger_garrison@xxxxxxxx
or at 727-803-8747, ext. 3061.
Invasive carp and the secret language of scent: The chemical language
of invasive Asian carp may eventually be turned against them in the fight
to help eradicate these harmful invaders from the Mississippi River.
Asian carp, introduced into the Mississippi River in the 1970s and 80s,
are now abundant throughout the lower Missouri, the Mississippi and Ohio
rivers, posing a threat to native species. Carp seem to have a chemical
language effective for predator defense and reproduction in murky environments,
so researchers put this language to the test by subjecting young carp to
extracts prepared from the skins of other carp. The result: the young carp,
upon detecting the extracts, significantly avoided them by moving from
the area, becoming immobile, and schooling. This “alarm substance” may
be effective in repelling carp from habitat critical to native species.
Young carp were also attracted to the chemical stimuli of schooling carp,
which can assist in conventional eradication methods. This study,
Use of pheromones to control invasive Asian carp, will be presented
on Nov. 20t at 10:40 a.m. in the Elmwood Room. To learn more,
contact Robin Calfee at rcalfee@xxxxxxxx
or at 573-441-2969.
Toxic algae may be harming endangered suckers in Klamath Lake: Preliminary
data suggest that algal toxins may be hindering the population growth of
endangered Lost River suckers and shortnose suckers in Upper Klamath Lake
in southern Oregon. This lake is characterized by high levels of nitrogen
and phosphorus, nutrients that promote large, frequent cycles of cyanobacterial
or algal blooms from spring through fall. Researchers evaluated the presence
and effects of these toxins, specifically microcystins, which are harmful
to other aquatic life, in the lake’s water and in fish from the lake.
Examination of liver tissues from juvenile suckers revealed adverse physiological
effects consistent with tissue damage associated with microcystin exposure.
Significant concentrations of the toxins were reported form all field sampling
stations in the lake. This study, Cyanobacterial toxins
found in Upper Klamath Lake, Oregon: implications for endangered fish,
will be presented on Nov. 22 at 1:10 p.m. in Ballroom C. To learn more,
contact Kathy Echols at kechols@xxxxxxxx
or at 573-876-1838.
Wading through the sources of
lake contamination: Contamination of urban lakes and streams by polycyclic
aromatic hydrocarbons (PAHs) is widespread and has been increasing over
the last 40 years in the United States. These PAHs can be toxic to bottom-dwelling
organisms, can cause tumors in fish, and several are believed to cause
cancer in humans. In this study, researchers examined five sources
of PAHs in 40 urban lakes from across the United States, including coal-tar-based
pavement sealcoat, coal combustion, oil combustion, vehicle emissions and
wood combustion. Of the five sources studied, sealcoat was the strongest
contributor to PAH contamination in lake sediment. This research can help
those trying to reduce pollution levels in the urban environment by providing
them with a better understanding of PAH sources. This study, Sources
of PAHs to urban lakes in the United States, will be presented on Nov.
23 at 11:20 a.m. in the Jefferson Room. For more information, contact Peter
Van Metre at pcvanmet@xxxxxxxx
or at 512-927-3506.
Tiny particles with big effects: Industrially produced nanoparticles
are being dispersed into the environment from a range of everyday human
activities. Use of consumer nanoproducts, such as sunscreen with zinc oxide
or bed sheets and socks containing silver nanoparticles, all have the potential
to release metals into the environment. Some of these particles can be
toxic, but little is known about how nanoparticles will accumulate in the
environment. Interactions between nanoparticles and living organisms are
influenced by the unique physico-chemical properties of each kind of nanoparticle.
This study introduces a new approach to evaluate the toxicity of nanoparticles
with metal as an ingredient, and offers a way to begin to understand potential
beneficial uses and potential environmental risks. This study, Characterizing
the bioavailability and toxicity of engineered nanoparticles using enriched
isotope tracers and biodynamic modeling, will be presented on Nov.
22 at 10 a.m. in the Oak Alley Room. For more information, contact Marie-Noele
Croteau at mcroteau@xxxxxxxx
or at 650-329-4424.
Cause of feminized male sturgeon remains elusive: The number of male
shovelnose sturgeon with female characteristics in the Missouri River has
increased from about 3 percent in 1968 to 15 percent in 2001. USGS researchers
examined the levels of PCBs (polychlorinated biphenyls) and organochlorine
pesticides in normal and intersex fish to see whether these hormone-mimicking
compounds were associated with the condition. Although the compounds were
all present in sturgeon at levels of concern, no differences in levels
between intersex male fish and normal male fish were detected. Still, reproductive
development is complex and can depend on many factors, including a fish’s
age at its first exposure. These fish are also exposed to many other
compounds that have not yet been tested. Recent findings of intersex in
endangered pallid sturgeon underscore the need to find the cause of this
condition. This study, Intersex gonads in Missouri River shovelnose
sturgeon: occurrence, severity, and association with contaminants,
will be presented on Nov. 22 at 8:40 a.m. in Ballroom A. To learn more,
contact Diane Papoulias at dpapoulias@xxxxxxxx
or at 573-999-1788.
USGS provides science for a changing world. For more information, visit www.usgs.gov.
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