Brief Summary of Major Accomplishments during 2012-2013
Research Translation Core – Brown SRP Supports Cleanup of Blackstone River
Through its Research Translation Core (RTC), the Brown University Superfund Research Program (SRP) joined an interdisciplinary effort to test the Eco-Machine, the only bioremediation unit in the country that uses fungi, plants, and bacteria to naturally clean up oil and other contaminants in water. Initial results show that the Eco-Machine reduces petroleum hydrocarbons in river water by as much as 90%.
Woods Hole scientist John Todd created the Eco-Machine to restore and remediate the Fisherville Mill site in Grafton, MA. The site, a former textile manufacturing facility, is next to the Blackstone River, which flows into Rhode Island, and is contaminated primarily by heating oil released from storage tanks. The Eco-Machine began operating in May 2012 to treat water in the river by reducing industrial petroleum hydrocarbons as well as nitrogen and phosphorous from stormwater. Researchers at Brown SRP partnered with Todd to test the machine’s ability to clean up such pollutants in the Blackstone River.
Brown is also working with a research group from Clark University to test the bioremediation potential of the fungi and with Fisherville Mill Redevelopment Corp., John Todd Ecological Design, the town of Grafton, and EPA Region 1 to monitor petroleum hydrocarbons in the river water. Researchers at Brown SRP are analyzing river sediment and water from multiple locations in the river and from the Eco-Machine tanks.
This truly interdisciplinary effort is significant because it aims for sustainable redevelopment, minimum impact remediation, improved public health, community involvement and support, and development of a “living laboratory” for students and researchers of varied disciplines and levels of expertise. The intent is to use this project as a model for other contaminated sites.
Projects 2 and 6 – Development of Graphene-Based Environmental Barriers
Barrier films are used widely in consumer, industry, and military technologies. They protect personnel, equipment, devices, foods and pharmaceutical products from exposure to agents that are toxic, reactive, or induce spoilage or degrade performance. Engineered barriers used to protect human health or the environment include landfill liners and caps, packaging for shipping and recycling of hazardous wastes, architectural barriers to protect homes from the intrusion of radon or volatile chemicals from the underlying soil, and textiles that prevent human exposure to airborne toxic chemicals or biochemical warfare agents.
Common plastic films are typically poor barriers, and fillers or coatings are needed to improve their barrier performance for practical use. Graphene is a new sheet-like carbon-based material first discovered in 2004, and for which the Nobel Prize was granted in 2010. Graphene is only one atom thick, yet able to resist the penetration of even the smallest molecules. Research led by SRP Investigator Robert Hurt at Brown University has recently shown that ultrathin films of chemically modified graphene can serve as effective barriers for toxic vapors [Guo et al., 2012]. Small graphene flakes were deposited on plastic films to produce uniform tile-like coatings, which were only 5 – 40 atoms thick, yet able to effectively block the penetration of mercury vapor, the potent neurotoxicant. The researchers used a form of chemically modified graphene that is easily produced from mined natural graphite as a feedstock, and the ultrathin nature of the films leads to low-mass requirements and potentially low cost. This research also used an environmentally friendly water-based coating process that will make ultrathin graphene films an attractive and sustainable barrier technology.
The Brown research also involves a parallel study of the safety aspects associated with use of this new platform material, graphene. SRP investigator Agnes Kane is leading an effort to understand the effects on target cells in the lungs exposed to graphene flakes of different size, structure, and chemical composition [Sanchez et al. 2012, Creighton et al., 2012]. The overall goal of this interdisciplinary team is to development graphene-based environmental barriers in a responsible manner that considers both performance and potential human health impacts in the development and design phases.
Project 5 – Biological Dosimetry of Hexavalent Chromium
Hexavalent chromium (chromium-6, chromate) is a widespread environmental contaminant that is present at several dozens of large Superfund sites and in drinking water in many areas of the United States and worldwide. The extent of human exposure to this cancer-causing metal has been uncertain due to the inability of the current methods to determine whether the source of chromium in blood or urine is toxic chromium-6 or innocuous dietary chromium-3. Past research by Dr. Zhitkovich, Leader of the Research Project 4 at Brown University Superfund Program, identified DNA lesions (chromium-DNA adducts) that were specific to chromate. The use of this DNA damage for the assessment of human exposure to chromate requires a sensitive assay that can work on small quantities of blood and handle large number of samples. To resolve these technical questions with the DNA damage measurements, Dr. Zhitkovich teamed up with Lynntech Inc. that has extensive expertise in the development of detection devices for various applications. Their efforts to develop a nanotechnology-based ultrasensitive sensor for chromium-DNA damage has received support from the US Air Force through a SBIR Phase I award.
Project 7 (ARRA with Boston University) – Boston University and Brown University Collaboration on Assessing Vapor Intrusion Exposure and Risk
Vapor intrusion, which involves the migration of subsurface vapors into indoor air spaces, poses many challenges for regulators, practitioners and communities. USEPA is expected to release its final guidance on vapor intrusion in the near future; however, many questions still remain about how to accurately and reliably characterize vapor intrusion risks at complicated sites. As part of an inter-SRP collaboration involving Brown University’s SRP and Boston University’s SRP, researchers conducted a vapor intrusion field study in a neighborhood in the Metro-Boston Area. The study involved collaboration with the Massachusetts Department of Environmental Protection (MADEP) as well as community members and homeowners. As part of the inter-SRP research, field samples were collected and compared to a vapor intrusion model previously developed by Brown University’s SRP. Results of the study indicate that conceptual site models for vapor intrusion should consider sewer lines as potential sources of volatile organic chemicals in indoor air, as well as geologic features that may restrict vapor transport. In addition, the research demonstrates that the integration of data, such as modeling results and field data, can be used to better understand site conditions and the potential for vapor intrusion to pose a risk.
The combination of expertise within this inter-SRP collaboration (public health science within Boston University’s SRP and engineering within Brown University’s SRP) provided a more holistic approach to consider vapor intrusion exposures. Consequently, the knowledge gained was much richer than would have occurred in the absence of an interdisciplinary approach. Due to the sharing of research findings with public health scientists at ATSDR, and remediation managers at EPA, our research becomes more valuable because we have an improved understanding of how public health science and engineering, together, can enhance the protection of public health. For example, at the request of ASTDR and EPA, we have provided technical input on two National Priorities List (NPL) sites. Most recently, Dr. Kelly Pennell participated in the peer-review process for ATSDR Health Consultation for an NPL site in Alaska, referencing knowledge gained during the inter-SRP field study. The rich and multi-faceted experiences we gained as part of our research allow us to make more meaningful contributions when engaging with our stakeholders.
Trainee Success Story:
Elizabeth (Liz) Hoover, a graduate student in the Department of Anthropology at Brown University, worked with Phil Brown on the Community Engagement Core as an Environmental Leadership Program Fellow. Her doctoral dissertation on environmental health concerns in the Mohawk community of Akwesasne was supported by a Ford Foundation Diversity Fellowship in 2009. As a Native American, Liz has established close ties with the Narragansett Tribe in Rhode Island and will work together with Robert Vanderslice and Marcella Thompson on the Community Engagement Core during the next funding period. She is a tenure-track Assistant Professor of American Studies and Ethnic Studies at Brown University and has developed new courses for our trainees on Native American Health and the Environment. She has participated in a webinar on Environmental Justice: A Native American Prospective sponsored by the NIEHS Partnership for Environmental Public Health. As a former Superfund Research Program trainee, she will serve as a role model and mentor to facilitate bi-directional knowledge exchange between our trainees and the Narragansett Indian Tribe.