University of Illinois geneticist Michael Plewa said that disinfection by-products (DBPs) in water are the unintended consequence of water purification. "The reason that you and I can go to a drinking fountain and not be fearful of getting cholera is because we disinfect water in the United States," he said.
"But the process of disinfecting water with chlorine and chloramines and other types of disinfectants generates a class of compounds in the water that are called disinfection by-products. The disinfectant reacts with the organic material in the water and generates hundreds of different compounds. Some of these are toxic, some can cause birth defects, some are genotoxic, which damage DNA, and some we know are also carcinogenic."
The 10-year study began with an EPA grant to develop mammalian cell lines that would be used specifically to analyze the ability of these compounds to kill cells, or cytotoxicity, and the ability of these emerging disinfection by-products to cause genomic DNA damage.
"Our lab has assembled the largest toxicological data base on these emerging new DBPs. And from them we've made two fundamental discoveries that hopefully will aid the U.S. EPA in their regulatory decisions. The two discoveries are somewhat surprising," Plewa said.
The first discovery involves iodine-containing DBPs. "You get iodine primarily from sea water or underground aquifers that perhaps were associated with an ancient sea bed at one time. If there is high bromine and iodine in that water, when you disinfect these waters, you can generate the chemical conditions necessary to produce DBPs that have iodine atoms attached. And these are much more toxic and genotoxic than the regulated DBPs that currently EPA uses," he said.
Plewa said that the second discovery concerns nitrogen-containing DBPs. "Disinfectant by-products that have a nitrogen atom incorporated into the structure are far more toxic and genotoxic, and some even carcinogenic, than those DBPs that don't have nitrogen. And there are no nitrogen-containing DBPs that are currently regulated."
In addition to drinking water DBPs, Plewa said that swimming pools and hot tubs are DBP reactors. "You've got all of this organic material called 'people' -- and people sweat and use sunscreen and wear cosmetics that come off in the water. People may urinate in a public pool. Hair falls into the water and then this water is chlorinated. But the water is recycled again and again so the levels of DBPs can be ten-fold higher than what you have in drinking water."
Plewa said that studies were showing higher levels of bladder cancer and asthma in people who do a lot of swimming - professional swimmers as well as athletic swimmers. These individuals have greater and longer exposure to toxic chemicals which are absorbed through the skin and inhaled.
"The big concern that we have is babies in public pools because young children and especially babies are much more susceptible to DNA damage in agents because their bodies are growing and they're replicating DNA like crazy," he said.
Some public pools have been closed because they have high levels of bacteria. "Public pools keep a high level of chlorine in the water to keep bacteria and pathogens down but very little work research is conducted on evaluating levels of generated dangerous disinfection by-products.
"The idea is to keep the pools disinfected, keep them in compliance, just as with drinking water but then use engineering techniques that reduce the levels of these toxic by-products." Plewa described another project he is working on as a researcher with a National Science Foundation Center called WaterCAMPWS at the University of Illinois. "We're working with engineers and chemists to develop new technologies that will disinfect water, that will desalinate water, that will remove pharmaceuticals from water but in so doing, don't generate by-products that are even more toxic than the things you're trying to remove."
Ironically, the DBPs that are regulated by the EPA tend to be some of the least toxic DBPs in Plewa's study. "We've found that the emerging DBPs are much more genotoxic and much more cytotoxic. But I can't fault EPA because these data were not present at the time and in fact the development of the database of over 70 DBPs has been done in concert with our colleagues at the federal EPA."
Plewa said that until new technologies are engineered to safely disinfect the water in public pools, education is needed to encourage people to bathe or shower before entering a public pool. "It's the organic material that gets in the pool that is disinfected and then recirculated over and over again. That's why we call swimming pools disinfectant by-product reactors. But by public education, by personal behavior, there should be ways that we can reduce the levels of the dissolved organic material that should reduce the level of DBPs."
Plewa, along with a team of scientists received a United States Environmental Protection Agency Science and Technology award for their paper Occurrence, genotoxicity and carcinogenicity of regulated and emerging disinfection by-products in drinking water: A review and roadmap for research. It was published in the scientific journal Mutation Research.
Debra Levey Larson | EurekAlert!
Further reports about: > DBP > DNA > DNA damage > Disinfectants > EPA > Illinois River Watershed > Science TV > Swimming Pools > birth defect > carcinogenic > chemical conditions > chlorine > disinfection of water > drinking water > new technologies > nitrogen-containing DBPs > organic material > toxicological data base > water purification > water yielding toxic consequences
Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.
How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Life Sciences
15.12.2017 | Life Sciences
15.12.2017 | Physics and Astronomy