Drinking water can transmit a number of diseases, including typhoid, dysentery, cholera, and diarrhea, which can then spread explosively throughout an entire service area. To avoid this problem, drinking water must be disinfected.
After treatment and disinfection, the water is usually safe. To manage the disease risk until it reaches the tap, most waterworks throughout the world use chlorine or chlorine-containing chemicals for disinfection. Beneficial though the chlorination of water may be, it does have one potential drawback: studies have suggested that there may be a connection between the ingestion of chlorinated tap water and an increased risk of bladder cancer.
Scientists at the University of Alberta in Canada have now revealed a chlorination by-product of great interest: As the team led by Xing-Fang Li reports in the journal Angewandte Chemie, they were able to detect traces of the toxic compound dichloroquinone.
Chlorination has been use to disinfect water for decades. Through reactions with natural organic molecules in the water, it can lead to formation of trace amounts of toxic by-products, such as chloroform and halogenated acetic acid derivatives. The maximum allowed concentrations of these substances were legally regulated some years ago. Newer studies have suggested that these substances are not likely to pose a cancer risk. Instead, other possible by-products, such as halogenated quinones, which may be present in treated water at previously undetectable concentrations, are now under suspicion. Quinones are six-membered carbon rings with two oxygen atoms bound by double bonds to opposite ends of the molecule, and they occur in some microorganisms. Quinones that also contain halogen atoms such as chlorine or bromine may react with DNA and proteins at very low concentrations, causing damage to organisms.
The Canadian team has now been the first to successfully identify a representative of this class of compounds, 2,6-dichloro-1,4-benzoquinone, in chlorinated drinking water. To accomplish this, the researchers had to develop a special analytical procedure based on liquid chromatography (LC), electrospray ionization (ESI), and tandem mass spectrometry (tandem-MS). In actual water samples, they used this technique to detect this compound in quantities of a few nanograms per liter of water. The toxicology of some chloroquinones indicates that they could pose a risk of bladder cancer.
Author: Xing-Fang Li, University of Alberta, Edmonton (Canada), http://www.ualberta.ca/~xingfang/contact.html
Title: A Toxic Disinfection By-product, 2,6-Dichloro-1,4-benzoquinone, Identified in Drinking Water
Angewandte Chemie International Edition 2010, 49, No. 4, Permalink: http://dx.doi.org/10.1002/anie.200904934
Further reports about: > 4-benzoquinone > Angewandte Chemie > Bladder cancer > Drinking Habits > Nanogram concentrations > Quinones > chlorine-containing chemicals > chloroquinones > disinfection > drinking water > electrospray ionization > liquid chromatography > organic molecule > oxygen atom > traces
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering