National Center for Biotechnology Information
mardi 14 avril 2015
THE NATIONAL CENTER FOR BIOTECHNOLOGY INFORMATION ADVANCES SCIENCE AND HEALTH BY PROVIDING ACCESS TO BIOMEDICAL AND GENOMIC INFORMATION
INCREASED TRAFFIC ACCIDENT RATES ASSOCIATED WITH SHALE GAS DRILLING IN PENNSYLVANIA
OBJECTIVES : We examined the association between shale gas drilling and motor vehicle accident rates in Pennsylvania.
METHODS : Using publicly available data on all reported vehicle crashes in Pennsylvania, we compared accident rates in counties with and without shale gas drilling, in periods with and without intermittent drilling (using data from 2005 to 2012). Counties with drilling were matched to non-drilling counties with similar population and traffic in the pre-drilling period.
RESULTS : Heavily drilled counties in the north experienced 15-23% higher vehicle crash rates in 2010-2012 and 61-65% higher heavy truck crash rates in 2011-2012 than control counties. We estimated 5-23% increases in crash rates when comparing months with drilling and months without, but did not find significant effects on fatalities and major injury crashes. Heavily drilled counties in the southwest showed 45-47% higher rates of fatal and major injury crashes in 2012 than control counties, but monthly comparisons of drilling activity showed no significant differences associated with drilling.
CONCLUSIONS : Vehicle accidents have measurably increased in conjunction with shale gas drilling.
Authors : Graham J(1), Irving J(2), Tang X(3), Sellers S(2), Crisp J(2), Horwitz D(4), Muehlenbachs L(5), Krupnick A6, Carey D(2).
1) Center for Health Research, Geisinger Health System, Danville, PA, USA. Electronic address : email@example.com.
2) Weis Center for Research, Geisinger Health System, Danville, PA, USA.
3) Center for Health Research, Geisinger Health System, Danville, PA, USA.
4) De)partment of Orthopedics, Geisinger Health System, Danville, PA, USA.
5) Resources For the Future, Washington, DC, USA ; Department of Economics, University of Calgary, Calgary, Canada.
6) Resources For the Future, Washington, DC, USA.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25463961
MARCELLUS AND MERCURY : ASSESSING POTENTIAL IMPACTS OF UNCONVENTIONAL NATURAL GAS EXTRACTION ON AQUATIC ECOSYSTEMS IN NORTHWESTERN PENNSYLVANIA
Mercury (Hg) is a persistent element in the environment that has the ability to bioaccumulate and biomagnify up the food chain with potentially harmful effects on ecosystems and human health. Twenty-four streams remotely located in forested watersheds in northwestern PA containing naturally reproducing Salvelinus fontinalis (brook trout), were targeted to gain a better understanding of how Marcellus shale natural gas exploration may be impacting water quality, aquatic biodiversity, and Hg bioaccumulation in aquatic ecosystems. During the summer of 2012, stream water, stream bed sediments, aquatic mosses, macroinvertebrates, crayfish, brook trout, and microbial samples were collected. All streams either had experienced hydraulic fracturing (fracked, n = 14) or not yet experienced hydraulic fracturing (non-fracked, n = 10) within their watersheds at the time of sampling. Analysis of watershed characteristics (GIS) for fracked vs non-fracked sites showed no significant differences (P > 0.05), justifying comparisons between groups. Results showed significantly higher dissolved total mercury (FTHg) in stream water (P = 0.007), lower pH (P = 0.033), and higher dissolved organic matter (P = 0.001) at fracked sites. Total mercury (THg) concentrations in crayfish (P = 0.01), macroinvertebrates (P = 0.089), and predatory macroinvertebrates (P = 0.039) were observed to be higher for fracked sites. A number of positive correlations between amount of well pads within a watershed and THg in crayfish (r = 0.76, P < 0.001), THg in predatory macroinvertebrates (r = 0.71, P < 0.001), and THg in brook trout (r = 0.52, P < 0.01) were observed. Stream-water microbial communities within the Deltaproteobacteria also shared a positive correlation with FTHg and to the number of well pads, while stream pH (r = -0.71, P < 0.001), fish biodiversity (r = -0.60, P = 0.02), and macroinvertebrate taxa richness (r = -0.60, P = 0.01) were negatively correlated with the number of well pads within a watershed. Further investigation is needed to better elucidate relationships and pathways of observed differences in stream water chemistry, biodiversity, and Hg bioaccumulation, however, initial findings suggest Marcellus shale natural gas exploration is having an effect on aquatic ecosystems.
Authors : Grant CJ(1), Weimer AB, Marks NK, Perow ES, Oster JM, Brubaker KM, Trexler RV, Solomon CM, Lamendella R.
1) a Biology Department , Juniata College , Huntingdon , Pennsylvania , USA.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25734824
WELL WATER CONTAMINATION IN A RURAL COMMUNITY IN SOUTHWESTERN PENNSYLVANIA NEAR UNCONVENTIONAL SHALE GAS EXTRACTION
Reports of ground water contamination in a southwestern Pennsylvania community coincided with unconventional shale gas extraction activities that started late 2009. Residents participated in a survey and well water samples were collected and analyzed. Available pre-drill and post-drill water test results and legacy operations (e.g., gas and oil wells, coal mining) were reviewed. Fifty-six of the 143 respondents indicated changes in water quality or quantity while 63 respondents reported no issues. Color change (brown, black, or orange) was the most common (27 households). Well type, when known, was rotary or cable tool, and depths ranged from 19 to 274 m. Chloride, sulfate, nitrate, sodium, calcium, magnesium, iron, manganese and strontium were commonly found, with 25 households exceeding the secondary maximum contaminate level (SMCL) for manganese. Methane was detected in 14 of the 18 houses tested. The 26 wells tested for total coliforms (2 positives) and E. coli (1 positive) indicated that septic contamination was not a factor. Repeated sampling of two wells in close proximity (204 m) but drawing from different depths (32 m and 54 m), revealed temporal variability. Since 2009, 65 horizontal wells were drilled within a 4 km (2.5 mile) radius of the community, each well was stimulated on average with 3.5 million gal of fluids and 3.2 million lbs of proppant. PA DEP cited violations included an improperly plugged well and at least one failed well casing. This study underscores the need for thorough analyses of data, documentation of legacy activity, pre-drill testing, and long term monitoring.
Authors : Alawattegama SK(1), Kondratyuk T, Krynock R, Bricker M, Rutter JK, Bain DJ, Stolz JF.
1) a Center for Environmental Research and Education , Duquesne University , Pittsburgh , Pennsylvania , USA.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25734827
UNDERSTANDING THE RADIOACTIVE INGROWTH AND DECAY OF NATURALLY OCCURRING RADIOACTIVE MATERIALS IN THE ENVIRONMENT : AN ANALYSIS OF PRODUCED FLUIDS FROM THE MARCELLUS SHALE
BACKGROUND : The economic value of unconventional natural gas resources has stimulated rapid globalization of horizontal drilling and hydraulic fracturing. However, natural radioactivity found in the large volumes of "produced fluids" generated by these technologies is emerging as an international environmental health concern. Current assessments of the radioactivity concentration in liquid wastes focus on a single element - radium. However, the use of radium alone to predict radioactivity concentrations can greatly underestimate total levels.
OBJECTIVE : We investigated the contribution to radioactivity concentrations from naturally occurring radioactive materials (NORM), including uranium, thorium, actinium, radium, lead, bismuth, and polonium isotopes to the total radioactivity of hydraulic fracturing wastes.
METHODS : For this study we used established methods and developed new methods designed to quantitate NORM of public health concern that may be enriched in complex brines from hydraulic fracturing wastes. Specifically, we demonstrate the use of high purity germanium gamma spectrometry and isotope dilution alpha spectrometry to quantitate NORM.
RESULTS : We observed that radium decay products are initially absent from produced fluids due to differences in solubility. However, in systems closed to the release of gaseous radon, our model predicts that decay products will begin to ingrow immediately and (under these closed-system conditions) can contribute to an increase in the total radioactivity for over 100 years.
CONCLUSIONS : Accurate predictions of radioactivity concentrations are critical for estimating doses to potentially exposed individuals and the surrounding environment. These predictions must include an understanding of the geochemistry, decay properties, and ingrowth kinetics of radium and its decay product radionuclides.
Authors : Nelson AW(1), Eitrheim ES, Knight AW, May D, Mehrhoff MA, Shannon R, Litman R, Burnett WC, Forbes TZ, Schultz MK.
1) Interdisciplinary Human Toxicology Program, University of Iowa, Iowa City, Iowa, USA ; and University of Iowa State Hygienic Laboratory, Research Park, Coralville, Iowa, USA.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25831257
ENVIRONMENTAL HEALTH IMPACTS OF UNCONVENTIONAL NATURAL GAS DEVELOPMENT : A REVIEW OF THE CURRENT STRENGTH OF EVIDENCE
Rapid global expansion of unconventional natural gas development (UNGD) raises environmental health concerns. Many studies present information on these concerns, yet the strength of epidemiological evidence remains tenuous. This paper is a review of the strength of evidence in scientific reporting of environmental hazards from UNGD activities associated with adverse human health outcomes. Studies were drawn from peer-reviewed and grey literature following a systematic search. Five databases were searched for studies published from January 1995 through March 2014 using key search terms relevant to environmental health. Studies were screened, ranked and then reviewed according to the strength of the evidence presented on adverse environmental health outcomes associated with UNGD. The initial searches yielded >1000 studies, but this was reduced to 109 relevant studies after the ranking process. Only seven studies were considered highly relevant based on strength of evidence. Articles spanned several relevant topics, but most focussed on impacts on typical environmental media, such as water and air, with much of the health impacts inferred rather than evidenced. Additionally, the majority of studies focussed on short-term, rather than long-term, health impacts, which is expected considering the timeframe of UNGD ; therefore, very few studies examined health outcomes with longer latencies such as cancer or developmental outcomes. Current scientific evidence for UNGD that demonstrates associations between adverse health outcomes directly with environmental health hazards resulting from UNGD activities generally lacks methodological rigour. Importantly, however, there is also no evidence to rule out such health impacts. While the current evidence in the scientific research reporting leaves questions unanswered about the actual environmental health impacts, public health concerns remain intense. This is a clear gap in the scientific knowledge that requires urgent attention.
Authors : Werner AK (1), Vink S(2), Watt K(3), Jagals P(4).
1) Sustainable Minerals Institute, The University of Queensland, St. Lucia, Queensland, Australia. Electronic address : firstname.lastname@example.org.
2) Sustainable Minerals Institute, The University of Queensland, St. Lucia, Queensland, Australia.
3) College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia ; School of Population Health, The University of Queensland, Herston, Queensland, Australia.
4) School of Population Health, The University of Queensland, Herston, Queensland, Australia.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25461113
HUMAN EXPOSURE TO UNCONVENTIONAL NATURAL GAS DEVELOPMENT : A PUBLIC HEALTH DEMONSTRATION OF PERIODIC HIGH EXPOSURE TO CHEMICAL MIXTURES IN AMBIENT AIR
Directional drilling and hydraulic fracturing of shale gas and oil bring industrial activity into close proximity to residences, schools, daycare centers and places where people spend their time. Multiple gas production sources can be sited near residences. Health care providers evaluating patient health need to know the chemicals present, the emissions from different sites and the intensity and frequency of the exposures. This research describes a hypothetical case study designed to provide a basic model that demonstrates the direct effect of weather on exposure patterns of particulate matter smaller than 2.5 microns (PM2.5) and volatile organic chemicals (VOCs). Because emissions from unconventional natural gas development (UNGD) sites are variable, a short term exposure profile is proposed that determines 6-hour assessments of emissions estimates, a time scale needed to assist physicians in the evaluation of individual exposures. The hypothetical case is based on observed conditions in shale gas development in Washington County, Pennsylvania, and on estimated emissions from facilities during gas development and production. An air exposure screening model was applied to determine the ambient concentration of VOCs and PM2.5 at different 6-hour periods of the day and night. Hourly wind speed, wind direction and cloud cover data from Pittsburgh International Airport were used to calculate the expected exposures. Fourteen months of daily observations were modeled. Higher than yearly average source terms were used to predict health impacts at periods when emissions are high. The frequency and intensity of exposures to PM2.5 and VOCs at a residence surrounded by three UNGD facilities was determined. The findings show that peak PM2.5 and VOC exposures occurred 83 times over the course of 14 months of well development. Among the stages of well development, the drilling, flaring and finishing, and gas production stages produced higher intensity exposures than the hydraulic fracturing stage. Over one year, compressor station emissions created 118 peak exposure levels and a gas processing plant produced 99 peak exposures over one year. The screening model identified the periods during the day and the specific weather conditions when the highest potential exposures would occur. The periodicity of occurrence of extreme exposures is similar to the episodic nature of the health complaints reported in Washington County and in the literature. This study demonstrates the need to determine the aggregate quantitative impact on health when multiple facilities are placed near residences, schools, daycare centers and other locations where people are present. It shows that understanding the influence of air stability and wind direction is essential to exposure assessment at the residential level. The model can be applied to other emissions and similar sites. Profiles such as this will assist health providers in understanding the frequency and intensity of the human exposures when diagnosing and treating patients living near unconventional natural gas development.
Authors : Brown DR(1), Lewis C, Weinberger BI.
1) a Southwest Pennsylvania Environmental Health Project, McMurray , Pennsylvania , USA.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25734822
FIELD SURVEY OF HEALTH PERCEPTION AND COMPLAINTS OF PENNSYLVANIA RESIDENTS IN THE MARCELLUS SHALE REGION
Pennsylvania Marcellus Shale region residents have reported medical symptoms they believe are related to nearby Unconventional Natural Gas Development (UNGD). Associations between medical symptoms and UNGD have been minimally explored. The objective of this descriptive study is to explore whether shale region Pennsylvania residents perceive UNGD as a health concern and whether they attribute health symptoms to UNGD exposures. A questionnaire was administered to adult volunteers with medical complaints in a primary-care medical office in a county where UNGD was present. Participants were asked whether they were concerned about health effects from UNGD, and whether they attributed current symptoms to UNGD or to some other environmental exposure. There were 72 respondents ; 22% perceived UNGD as a health concern and 13% attributed medical symptoms to UNGD exposures. Overall, 42% attributed one or more of their medical symptoms to environmental causes, of which UNGD was the most frequent. A medical record review conducted on six participants who attributed their medical symptoms to UNGD revealed that only one of these records documented both the symptoms in question and the attribution to UNGD. The results of this pilot study suggest that there is substantial concern about adverse health effects of UNGD among Pennsylvania Marcellus Shale residents, and that these concerns may not be adequately represented in medical records. Further efforts to determine the relationship between UNGD and health are recommended in order to address community concerns.
Authors : Saberi P, Propert KJ, Powers M, Emmett E, Green-McKenzie J.
sources of information - LinkOut - more resources : http://www.ncbi.nlm.nih.gov/pubmed/25003172