Treating PCBs Without Dredging
Rensselaer researchers have discovered a tiny bacterium that could be the key to developing methods that help detoxify commercial polychlorinated biphenyl (PCB) compounds without the need for dredging. Using sediments from the Housatonic River, Biology Professor Donna Bedard identified that microbes belonging to a group of bacteria known as Dehalococcoides (Dhc) were breaking down the PCBs naturally. Researchers proved that the Dhc bacteria thrive on the PCBs, much as humans thrive on oxygen, replacing the chlorines on the PCBs with hydrogen, which begins the PCB degradation process.
Monitoring Nanomaterial Risk
The size, type, and dispersion of nanomaterials could all play a role in how these materials impact human health and the environment, according to Rensselaer researchers. Assistant Professor of Biomedical Engineering Deanna Thompson led a study to examine the impact of carbon nanotubes on the growth of rat heart muscle cells to better understand how they will ultimately affect human tissue and organs. The research revealed that the finely dispersed material inhibited animal cell growth more than larger clusters of nanotubes. Anurag Sharma, assistant professor of earth and environmental sciences, led a study to monitor bacterial growth in the presence of carbon nanotubes to help better understand how the introduction of nanoscale materials might impact the environment over an extended period of time. The study showed that while the nanotubes sustained bacterial growth, they may have also induced a stress-related impact on the biological activity of the bacteria.
The Next Great Earthquake
In the March 23 issue of Science, Robert McCaffrey, professor of earth and environmental sciences, urged the public and policy makers to consider all subduction-type tectonic boundaries to be “locked, loaded, and dangerous.” M9 earthquakes like the 2004 Sumatra-Andaman earthquake that caused the deadly tsunami can be created by only 20 meters of slip between two plates in a subduction zone, and slips of this length only occur so infrequently that there are no reliable historic records to track their frequency, according to McCaffrey. He urges officials to consider all subduction zones as lethal.