This grant will be used to acquire a quadrupole inductively coupled plasma mass spectrometer (ICPMS) with a laser ablation (LA) system to support research in geosciences, chemistry, biology and anthropology at Washington College. The quadrupole LA-ICPMS is a highly flexible instrument capable of sensitive and precise measurements of a wide range of elements in liquid or solid samples. The LA-ICPMS will be used in the exploration of benign synthetic pathways for the production of modern electroceramics, in the analysis of solar wind elemental ratios by stepped etching of lunar soil grains, in a study of the impacts of prescribed burning on the chemistry of a weathered soil on the mid-Atlantic Coastal Plain, in a study of the interactions of toxic metals with DNA repair, in trace element sourcing of metal artifacts and lithic materials from archaeological sites, and in an investigation of heavy metal contamination in bottom sediments in marinas on the Chester River in Maryland in collaboration with the Chester River Association and teachers and students from the Kent County STEM (science technology engineering mathematics) academy.
The research performed using the LA-ICPMS will create new opportunities for faculty-student collaborative research and experiential learning at Washington College, which will improve recruitment of science majors, and enhance research training for students going on to graduate school and industry. In particular, the investigation of metal contamination in Chester River sediments will facilitate scientific outreach to local organizations and public schools, thereby promoting scientific research among high school students and citizens in our community. The presence of the instrument will also enhance our efforts to attract underrepresented groups and women to scientific fields by creating research opportunities for undergraduates and high school students from diverse backgrounds. The involvement of researchers from multiple disciplines will generate excitement about science on our campus and in our community by promoting the continuing growth of the scientific research culture at Washington College.
An NSF-MRI grant supported the acquisition of an inductively coupled plasma mass spectrometer (ICPMS) with laser ablation system to conduct multidisciplinary research at Washington College in Chestertown, Maryland. The ICPMS is capable of rapidly determining the abundances of multiple elements in natural samples down to the sub-part-per-billion level. This capability allowed a team of faculty to embark on a wide-ranging multidisciplinary research program. Among numerous projects pursued, significant progress was made on a program to understand transport and fate of trace elements in water and bottom sediments of a local river, the Chester, which is a 70-km long tributary and a sub-estuary of Chesapeake Bay. This research has the goal of testing the hypotheses that sediment and water from different sources can be identified on the basis of trace element compositions, that water quality field surveys and trace element analyses of sediment and water will help to reveal naturally-occurring and man-made chemical inputs into the system, and that the spatial distributions of trace elements in the water column and in sediments can inform our understanding of the dynamics, geochemistry and ecosystem quality of the Chester River. To test these ideas, a comprehensive sediment and water sampling survey of the Chester River and its tidal tributaries commenced in 2011 and continues to the present. Results of our ICPMS analysis of trace elements in surface sediments suggest that most elements have significant crustal weathering sources. However spatial enrichments of silver, lead, copper and zinc were also observed in some tributaries. These enrichments could be from anthropogenic sources and/or may result from focused accumulation associated with organic-rich sediments. However most of these pollutants are present at levels below environmental concern. Results from the analyses of sediment cores collected at selected depositional sites show that lead and silver were more concentrated in the most recently-deposited sediments. This indicates that the beginning of anthropogenic contamination occurred within the last few hundred years. Analyses of water samples acquired along the length of the Chester River during discrete tidal stages were performed to help understand mixing of water from Chesapeake Bay with the fresh water sources in the Chester River watershed. Our results show that Arsenic, Chromium, Vanadium, Tungsten and Uranium concentrations are enriched in the more saline Bay waters while Barium and other metals have strong freshwater signatures. Continuing studies of trace elements in the water column will help inform previous work on the hydrodynamics and transport and fate of pollutants in the Chester. Preliminary evidence suggests that the presence of metals may have important biological impacts. Our studies of how lead, copper and tin are bound in the sediments suggests some degree of chemical mobility, and by inference, bioavailability. Further, one of our research students conducted a project focused on larval salamander development and mortality in vernal pools within the watershed and observed that mortality correlates with increasing trace metal concentration in sediment and water. To understand how metals of environmental concern cycle through the food web in the Chester River, we have begun a study of benthic organisms (mainly Rangia cuneata clams) that were found in sediment samples. Ongoing work seeks to understand the extent of metal assimilation by these organisms. In a separate line of inquiry, one of our faculty researchers and her students used the ICPMS to study the effects of exposure of human cells to cadmium, nickel, and/or cobalt on intracellular metal concentration, metal adduct formation, and the efficiency of DNA repair. They found that co-exposure to various combinations of metals (cadmium/nickel, cobalt/nickel, cadmium/cobalt) resulted in a decrease in intracellular metal concentration but a significant amount of programmed cell death and decreased DNA repair. Ongoing research at the NSF-supported lab seeks to advance the goal of understanding the hydrology and geochemistry of the Chester River among numerous other projects. This work may have a broader impact on environmental management strategies within the watershed, which may be directly scalable and transferable to the Chesapeake Bay and other environmentally sensitive coastal estuaries. Furthermore, as researchers at a teaching-focused institution, we strive to create high quality, hands-on research experiences for undergraduate STEM students. The proximity of the Chester River and its consequent availability for fieldwork, the economic and environmental importance of the River, and the possibility of using the River and its watershed as a test bed for practices that may improve environmental quality, all combine to create unique opportunities for collaborative research and research-based teaching. The new NSF-supported lab has been central to developing these synergies. Our research has furthermore formed the basis of numerous partnerships between College departments and programs and with outside institutions and non-profits. The results of our ongoing research continue to be shared among our partnering organizations and disseminated through public lectures, scientific articles, national and regional conference presentations, the world wide web, and public interest science articles.
