"To the best of our knowledge, this is the first published report of PCB11 in ambient air," said Keri Hornbuckle, UI professor of civil and environmental engineering, in the Sept. 24 online issue of the journal Environmental Science & Technology. The journal can be found at http://pubs.acs.org/journals/esthag/.
"This compound is ubiquitous in air throughout the city of Chicago," said Hornbuckle, who is also a researcher at the renowned Iowa research institute IIHR-Hydroscience and Engineering.
"We do not know if there are any health concerns associated with this compound but there are very few published studies of its toxic properties," she said.
To conduct the test, UI researchers mounted air sample collection devices on platforms attached to the rear of two medical clinic vans provided by the Mobile C.A.R.E. Foundation of Chicago (Comprehensive Care for Chicagoland's Children with Asthma). The samples were collected during the six to eight hours each day that the vans visited sites, primarily elementary schools, where the mobile clinics provide service to students and their families.
In all, researchers found PCB11 in 91 percent of the 184 samples collected.
Regarding the possible source of the substance, Hornbuckle and her UI colleagues Dingfei Hu and Andres Martinez reported, "The wide distribution of PCB11 in Chicago air is consistent with volatilization of this compound from painted surfaces although the actual source of PCB11 is unknown."
Historically, PCB11 is one of 209 compounds manufactured between the late 1920s and the 1970s. The report noted that they were primarily marketed as mixtures called Aroclors by chemical companies until U.S. production ceased in the late 1970s. The distribution of PCB11 throughout residential areas of Chicago suggests that the compound is a past or current component of consumer paint products.
The report also said that the historical trend for PCB11 is unknown and probably different from that for Aroclors -- particularly if PCB11 is produced as a by-product of current paint manufacturing -- and that Aroclor-PCBs in the environment are decreasing worldwide, but this may not be the case for PCB11.
The prevalence of PCB11 in Chicago air suggests that there are either multiple current sources in the city or that this compound is ubiquitous in background air. This has important implications for human exposure to this potentially toxic compound, according to the study.
"While inhalation is not widely considered to be a major exposure route for higher molecular weight PCBs, it may be an important route for PCB11," Hornbuckle said. "Not only is PCB11 one of the most volatile PCBs, if it is present in interior paints, then indoor concentrations may be much higher than reported here."
Concluding that further study is needed, Hornbuckle and her colleagues said "Consumption of paint chips could be also a direct exposure route for children. It is also possible that PCB11 is present not only in Chicago, but in air elsewhere and also in fish, soil, water, food and humans."
Funding for the research project was provided by the National Institute for Environmental Health Sciences (NIEHS/NIH) Superfund Basic Research Program.
STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500
MEDIA CONTACTS: Keri Hornbuckle, UI College of Engineering, 319-384-0789 (office), 319-331-3053 (cell), firstname.lastname@example.org; Gary Galluzzo, University News Services, 319-384-0009, email@example.com
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 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences