Many chemicals commonly used in medications such as over-the-counter painkillers or birth control pills end up far from their intended destination - in American streams. According to a new report, published online today by the journal Environmental Science and Technology, a number of the waterways contain complex cocktails of compounds.
The 30-state study, conducted by the U.S. Geological Survey, tested 139 streams for 95 organic contaminants - ranging from medications and hormones to insecticides and fire retardants--between 1999 and 2000. In 35 percent of the waterways, the researchers found 10 or more compounds and 80 percent of the sites harbored at least one chemical. In one particularly polluted stream, the team detected 38 contaminants. The most frequently encountered compounds included the steroids coprostanol and cholesterol, the insect repellant DEET, triclosan (the active ingredient in antimicrobial soaps) and caffeine.
Because this was the first attempt to clarify the distribution of these so-called pharmaceuticals and personal care products (PPCPs), the scientists specifically chose streams likely to display contamination such as those near urban areas or livestock production facilities. Thus, they should not be considered representative of all streams in the U.S. And although the plethora of pollutants is discouraging, most of their concentrations were low, often measuring less than one part per billion. The scientists note, however, that some hormones can affect aquatic life at exceedingly low concentrations and that the potential toxicological effects of many of the detected chemicals remain unclear.
Sarah Graham | Scientific American
New yeast species discovered in Braunschweig, Germany
13.12.2019 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Saliva test shows promise for earlier and easier detection of mouth and throat cancer
13.12.2019 | Elsevier
Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level.
For viruses to multiply, they usually need the support of the cells they infect. In many cases, only in their host’s nucleus can they find the machines,...
More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?
It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...
In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.
Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...
The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.
Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.
Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
13.12.2019 | Materials Sciences
13.12.2019 | Medical Engineering
13.12.2019 | Physics and Astronomy