"I'm not implying that drinking disinfected water will give you Alzheimer's," said Michael Plewa, lead scientist and professor of genetics in the U of I Department of Crop Sciences. "Certainly, the disinfection of drinking water was one of the most significant public health achievements of the 20th century. But the adverse effects of disinfection byproducts (DBPs) that are unintentionally formed during this process are causing concerns as researchers unveil their toxicity."
More than 600 DBPs have been discovered. Although researchers know some DBPs are toxic, little biological information is available on the majority of these water contaminants. The Environmental Protection Agency regulates only 11 of these DBPs, he said.
Plewa's laboratory investigated the biological mechanism, or the cellular target that leads to toxicity, in the second-most prevalent DBP class generated in disinfected water – haloacetic acids (HAAs).
"The EPA has regulated HAAs for nearly 15 years. However, we did not know how they caused toxicity before this study," he said. "Now that we've uncovered the mechanism for HAAs, we can make sense of past data that can lead to new studies relating to adverse pregnancy outcomes, different types of cancer, and neurological dysfunction."
Plewa believes this will assist the EPA in establishing regulations based on science. Their research will also help the water treatment community develop new methods to prevent the generation of the most toxic DBPs.
"It's fairly simple," Plewa said. "To increase the health benefits of disinfected water, we must reduce the most toxic DBPs. If we understand their biological mechanisms, we can come up with more rational ways to disinfect drinking water without generating toxic DBPs."
In this study, researchers focused on three HAAs – iodoacetic acid, bromoacetic acid and chloroacetic acid. After they rejected their first hypothesis that the HAAs directly damaged DNA, they looked at research in a different area – neuroscience. Plewa's graduate student, Justin Pals, discovered an amazing connection, Plewa said.
In neurotoxicology, iodoacetic acid reduces the availability of nutrients or oxygen in neurons by inhibiting glyceraldehyde-3-phosphate dehydrogenase (GAPDH).
"Researchers are interested in understanding how to prevent damage after a stroke or other neurological damage," Plewa said. "Iodoacetic acid kills these cells. One of the targets they found was that iodoacetic acid inhibited GAPDH."
Plewa's lab conducted quantitative GAPDH enzyme kinetics and discovered that the data were highly correlated with a diversity of adverse health markers.
"All the pieces of the puzzle fell into place in an instant," Plewa said. "We had discovered our cellular target – GAPDH. Never before had this type of research been done with this level of precision and associated with a large body of adverse biological impacts."
They discovered that the HAA disinfection byproducts were toxic because the cells cannot make ATP, and this causes oxidative stress.
"Cells treated with HAAs experience DNA damage," Plewa said. "So they start expressing DNA repair systems. HAAs are not directly damaging DNA, rather they are inhibiting GAPDH, which is involved in increasing the oxidative stress that we are observing."
A growing body of information has shown that GAPDH is associated with the onset of neurological diseases.
"If you carry a natural mutation for GAPDH and are exposed to high levels of these disinfection byproducts, you could be more susceptible to adverse health effects such as Alzheimer's," he said.
More research is needed to study iodinated disinfection byproducts because they are the most reactive in inhibiting GAPDH function and are currently not regulated by the EPA, Plewa said.
"We replaced the standard working model of direct DNA damage with a new working model based on a cellular target molecule," he said. "This discovery is a fundamental contribution to the field of drinking water science."
This research, "Biological Mechanism for the Toxicity of Haloacetic Acid Drinking Water Disinfection Byproducts," was published in Environmental Science & Technology. Scientists include Michael Plewa, Justin Pals, Justin Ang and Elizabeth Wagner, all of the University of Illinois. Research was supported by the WaterCAMPWS Center NSF Award CTS-0120978.
Jennifer Shike | EurekAlert!
Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
27.04.2017 | Health and Medicine
27.04.2017 | Information Technology
26.04.2017 | Materials Sciences