Office of Research and Development Publications

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In 1903 the genus name Enterococcus was proposed for gram-positive, catalase-negative, coccoid-shaped bacterial of intestinal origin. Several years later, it was suggested that the genus name be changed to Streptococcus because of the organisms' ability to form chains of coccoid...

Graphene family nanomaterials (GFNs) are widely used in the field of electronics and biomedicine. Gaps in our knowledge about fate and toxicity of GFNs, such as graphene oxide (GO), raise concerns regarding their environmental impacts. Filter feeding bivalves, such as Crassostrea...

Graphene is a two-dimensional nanomaterial with unique mechanical, thermal, electrical, and optical properties. With increasing applications of graphene-family nanomaterials (GFNs) in numerous fields such as electronics, biomedicine, and surface coatings, concern for their impact...

Genetics, obesity, age, and lifestyle are major susceptibility factors in the induction of asthma and can interact with environmental exposures either synergistically or antagonistically. Different environmental exposures that increase or decrease the likelihood of developing as...

A Bayesian belief network (BBN) was developed to characterize the effects of sediment accumulation on the water storage capacity of Lago Lucchetti (located in southwest Puerto Rico) and to forecast the life expectancy (usefulness) of the reservoir under different management scena...

The frequency of cyanobacteria blooms in North American lakes is increasing. A major concern with rising cyanobacteria blooms is microcystin, a common cyanobacterial hepatotoxin. To explore the conditions that promote high microcystin concentrations, we analyzed the US EPA Nation...

The frequency of cyanobacteria blooms in North American lakes is increasing. A major concernwith rising cyanobacteria blooms is microcystin, a common cyanobacterial hepatotoxin. Toexplore the conditions that promote high microcystin concentrations, we analyzed the US EPANational ...

The frequency of cyanobacteria blooms in North American lakes is increasing. A major concern with rising cyanobacteria blooms is microcystin, a common cyanobacterial hepatotoxin. To explore the conditions that promote high microcystin concentrations, we analyzed the US EPA Nation...

Background/Question/Methods Many environmental factors influence human mortality simultaneously. However, assessing their cumulative effects remains a challenging task. In this study we used the Environmental Quality Index (EQI), developed by the U.S. EPA, as a measure of overall...

Coastal ecosystems are affected by ever increasing natural and human pressures. Because the physical, chemical, and biological characteristics unique to each ecosystem control the ways that biological resources respond to ecosystem stressors, we recommend a flexible and adaptable...

The US EPA Office of Research and Development (ORD) has a fairly long, eventful, and largely successful QA history, in spite of the fact that the Agency' s QA focus has been elsewhere. For most of the past decade, we QA professionals in ORD have had little opportunity other than ...

In order to characterize and compare impoundments and natural drainage lakes, we classified 235 randomly selected lentic waterbodies (>1 ha) in the Northeast USA as human created, or natural. We compared geographic extent and distribution, morphology and hydrology, trophic state...

Chlorophyll a concentrations, colored dissolved organic matter (CDOM) absorption coefficients, and selected apparent optical properties (AOPs) of waters along the Western Passage of Narragansett Bay and adjoining Rhode Island Sound were determined from May -August 1999. Water sam...

This study was designed to define the degree of concentration addition found for mixtures of certain xenobiotics that are thought to act through a similar or different mode of toxic action for the acute mortality and sublethal growth toxicity endpoints, and for a freshwater fish ...

Variability in vegetation greenness was determined for the Galveston Bay watershed using biweekly Normalized Difference Vegetation Index (NDVI) data derived from the Advanced Very High Resolution Radiometer (A VHRR) flown on NOAA satellites. NDVI variability was compared with reg...

Three backwater areas in the Atchafalaya Basin, Louisiana, are compared. The three areas studied are Fordoche and Buffalo Cove, within the Atchafalaya Basin Floodway and subject to annual flooding by the Atchafalaya River, and Pat Bay which is located outside the floodway and in ...

Context <br>EPA Region 10, which comprises Alaska, Washington, Idaho, and Oregon, has 269 federally recognized Native American Tribes. It is has been documented that Tribal members consume much larger quantities of fish than the general population. ORD's Human Studies Division...

In June 2006, the US Supreme Court issued decisions in two cases concerning the Clean Water Act (CWA). The decisions discuss factors potentially relevant to CWA jurisdiction, including the hydrological permanence of non-navigable streams and adjacent wetlands (NNSAWs) and their ...

For chemicals with a common mechanism of toxicity, relative potency factors (RPFs) allow dose and exposure measures to be normalized to an equivalent toxicity amount of a model chemical... In ecological risk assessments the large number of possible target species, variety of expo...

A conceptual model was developed that relates an estuarine system's anthropogenic inputs to it's ecological integrity. Ecological integrity is operationally defined as an emergent property of an ecosystem that exists when the structural components are complete and the functional ...

Dimethylarsinic acid (DMA) has been used as an herbicide (cacodylic acid) and is the major metabolite formed after exposure to tri- (arsenite) or pentavalent (arsenate) inorganic arsenic (iAs) via ingestion or inhalation in both humans and rodents. Once viewed simply as a detoxi...

A continuous flow-through bioassay system is described for exposing marine test organisms and their various life stages to oil. The apparatus consists of two principal stages--one for administering the water-accommodated fractions of oil (WAF) and the second for administering 'wh...

A space saving portable mini-diluter exposure system for testing early life stages of fish and invertebrates has been developed and successfully used both in the laboratory and on-site with single chemicals and with complex effluents. This gravity-operated system can also be inst...

A critique of the use of hormesis in risk assessment.<br><br>Kitchin, KT; and Drane, Wanzer<br><br>Summary:<br>There are severe problems and limitations with the use of hormesis as the principal dose-response default assumption in risk assessment. These problems and limitations i...

Background: Millions of people are at risk from the adverse effects of waterborne arsenic. Although the cardiovascular effects of high exposures to arsenic have been well documented, few individual level prospective studies have assessed cardiovascular risk at moderate exposures....