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Augusta, ME, United States

Thompson W.B.,Maine Geological Survey | Griggs C.B.,Cornell University | Miller N.G.,140 Cultural Education Center | Nelson R.E.,Colby College | And 3 more authors.
Quaternary Research | Year: 2011

Excavations in the late-glacial Presumpscot Formation at Portland, Maine, uncovered tree remains and other terrestrial organics associated with marine invertebrate shells in a landslide deposit. Buds of Populus balsamifera (balsam poplar) occurred with twigs of Picea glauca (white spruce) in the Presumpscot clay. Tree rings in Picea logs indicate that the trees all died during winter dormancy in the same year. Ring widths show patterns of variation indicating responses to environmental changes. Fossil mosses and insects represent a variety of species and wet to dry microsites. The late-glacial environment at the site was similar to that of today's Maine coast. Radiocarbon ages of 14 tree samples are 11,907±31 to 11,650±5014C yr BP. Wiggle matching of dated tree-ring segments to radiocarbon calibration data sets dates the landslide occurrence at ca. 13,520+95/±20calyr BP. Ages of shells juxtaposed with the logs are 12,850±6514C yr BP (Mytilus edulis) and 12,800±5514C yr BP (Balanus sp.), indicating a marine reservoir age of about 1000yr. Using this value to correct previously published radiocarbon ages reduces the discrepancy between the Maine deglaciation chronology and the varve-based chronology elsewhere in New England. © 2011 University of Washington. Source

Flanagan S.V.,Lamont Doherty Earth Observatory | Flanagan S.V.,City University of New York | Marvinney R.G.,Maine Geological Survey | Johnston R.A.,Maine Geological Survey | And 4 more authors.
Science of the Total Environment | Year: 2015

Private wells in the United States are unregulated for drinking water standards and are the homeowner's responsibility to test and treat. Testing for water quality parameters such as arsenic (As) is a crucial first step for homeowners to take protective actions.This study seeks to identify key behavioral factors influencing homeowners' decisions to take action after receiving well As test results. A January 2013 survey of central Maine households (n. = 386, 73% response) who were notified 3-7. years earlier that their well water contained As above 10. μg/L found that 43% of households report installing As treatment systems. Another 30% report taking other mitigation actions such as drinking bottled water because of the As, but the remaining 27% of households did not act. Well water As level appears to be a motivation for mitigation: 31% of households with well water level between 10 and 50. μg/L did not act, compared to 11% of households with well water >. 50. μg/L. The belief that the untreated water is not safe to drink (risk) and that reducing drinking water As would increase home value (instrumental attitude) were identified as significant predictors of mitigating As. Mitigating As exposure is associated with less worry about the As level (affective attitude), possibly because those acting to reduce exposure feel less worried about As. Use of a treatment system specifically was significantly predicted by confidence that one can maintain a treatment system, even if there are additional costs (self-efficacy).An assessment of As treatment systems used by 68 of these households with well water As >. 10. μg/L followed up within August-November 2013 found that 15% of treatment units failed to produce water below As 10. μg/L, suggesting that there are continued risks for exposure even after the decision is made to treat. © 2014 Elsevier B.V. Source

Flanagan S.V.,Lamont Doherty Earth Observatory | Flanagan S.V.,City University of New York | Marvinney R.G.,Maine Geological Survey | Zheng Y.,Lamont Doherty Earth Observatory | And 2 more authors.
Science of the Total Environment | Year: 2015

In 2001 the Environmental Protection Agency (EPA) adopted a new standard for arsenic (As) in drinking water of 10. μg/L, replacing the old standard of 50. μg/L. However, for the 12% of the U.S. population relying on unregulated domestic well water, including half of the population of Maine, it is solely the well owner's responsibility to test and treat the water. A mailed household survey was implemented in January 2013 in 13 towns of Central Maine with the goal of understanding the population's testing and treatment practices and the key behavior influencing factors in an area with high well-water dependency and frequent natural groundwater As. The response rate was 58.3%; 525 of 900 likely-delivered surveys to randomly selected addresses were completed. Although 78% of the households reported that their well has been tested, half of it was more than 5. years ago. Among the 58.7% who believe they have tested for As, most do not remember the results. Better educated, higher income homeowners who more recently purchased their homes are most likely to have included As when last testing. While households agree that water and As-related health risks can be severe, they feel low personal vulnerability and there are low testing norms overall. Significant predictors of including As when last testing include: having knowledge that years of exposure increases As-related health risks (risk knowledge), knowing who to contact to test well water (action knowledge), believing that regular testing does not take too much time (instrumental attitude), and having neighbors who regularly test their water (descriptive norm). Homeowners in As-affected communities have the tendency to underestimate their As risks compared to their neighbors. The reasons for this optimistic bias require further study, but low testing behaviors in this area may be due to the influence of a combination of norm, ability, and attitude factors and barriers. © 2014 Elsevier B.V. Source

Flanagan S.V.,Lamont Doherty Earth Observatory | Marvinney R.G.,Maine Geological Survey | Smith A.E.,U.S. Center for Disease Control and Prevention | Chillrud S.N.,Lamont Doherty Earth Observatory | And 2 more authors.
Science of the Total Environment | Year: 2016

Arsenic is a naturally occurring toxic element often concentrated in groundwater at levels unsafe for human consumption. Private well water in the United States is mostly unregulated by federal and state drinking water standards. It is the responsibility of the over 13 million U.S. households regularly depending on private wells for their water to ensure it is safe for drinking. There is a consistent graded association with health outcomes at all levels of socioeconomic status (SES) in the U.S. Differential exposure to environmental risk may be contributing to this persistent SES-health gradient. Environmental justice advocates cite overwhelming evidence that income and other SES measures are consistently inversely correlated with exposure to suboptimal environmental conditions including pollutants, toxins, and their impacts. Here we use private well household surveys from two states to investigate the association between SES and risks for arsenic exposure, examining the potentially cumulative effects of residential location, testing and treatment behavior, and psychological factors influencing behavior. We find that the distribution of natural arsenic hazard in the environment is socioeconomically random. There is no evidence that higher SES households are avoiding areas with arsenic or that lower SES groups are disproportionately residing in areas with arsenic. Instead, disparities in exposure arise from differing rates of protective action, primarily testing well water for arsenic, and secondly treating or avoiding contaminated water. We observe these SES disparities in behavior as well as in the psychological factors that are most favorable to these behaviors. Assessment of risk should not be limited to the spatial occurrence of arsenic alone. It is important that social vulnerability factors are incorporated into risk modeling and identifying priority areas for intervention, which should include strategies that specifically target socioeconomically vulnerable groups as well as all the conditions which cause these disparities in testing and treatment behavior. © 2016 Elsevier B.V. Source

Yang Q.,Queens College, City University of New York | Yang Q.,Lamont Doherty Earth Observatory | Jung H.B.,Queens College, City University of New York | Marvinney R.G.,Maine Geological Survey | And 3 more authors.
Environmental Science and Technology | Year: 2012

A high percentage (31%) of groundwater samples from bedrock aquifers in the greater Augusta area, Maine was found to contain greater than 10 μg L -1 of arsenic. Elevated arsenic concentrations are associated with bedrock geology, and more frequently observed in samples with high pH, low dissolved oxygen, and low nitrate. These associations were quantitatively compared by statistical analysis. Stepwise logistic regression models using bedrock geology and/or water chemistry parameters are developed and tested with external data sets to explore the feasibility of predicting groundwater arsenic occurrence rates (the percentages of arsenic concentrations higher than 10 μg L -1) in bedrock aquifers. Despite the under-prediction of high arsenic occurrence rates, models including groundwater geochemistry parameters predict arsenic occurrence rates better than those with bedrock geology only. Such simple models with very few parameters can be applied to obtain a preliminary arsenic risk assessment in bedrock aquifers at local to intermediate scales at other localities with similar geology. © 2012 American Chemical Society. Source

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