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1.
Sci Rep ; 11(1): 16990, 2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34417535

RESUMEN

This work uses a high-quality 3D seismic volume from offshore Canterbury Basin, New Zealand, to investigate how submarine canyon systems can focus sub-surface fluid. The seismic volume was structurally conditioned to improve the contrast in seismic reflections, preserving their lateral continuity. It reveals multiple pockmarks, eroded gullies and intra-slope lobe complexes occurring in association with the Waitaki Submarine Canyon. Pockmarks are densely clustered on the northern bank of the canyon and occur at a water depth of 500-900 m. In parallel, near-seafloor strata contain channel-fill deposits, channel lobes, meandering channel belts and overbank sediments deposited downslope of the submarine canyon. We propose that subsurface fluid migrates from relatively deep Cretaceous strata through shallow channel-fill deposits and lobes to latter seep out through the canyon and associated gullies. The new, reprocessed Fluid Cube meta-attribute confirms that fluids have seeped out through the eroded walls of the Waitaki Canyon, with such a seepage generating seafloor depressions in its northern bank. Our findings stress the importance of shallow reservoirs (channel-fill deposits and lobes) as potential repositories for fluid, hydrocarbons, or geothermal energy on continental margins across the world.

2.
Artículo en Inglés | MEDLINE | ID: mdl-33641094

RESUMEN

The purpose of this study is to examine the relationship between renewable energy sources and sustainable economic growth of the South Asian Association for Regional Cooperation (SAARC) countries. This study uses three main renewable energy sources such as geothermal, hydro and wind. This study collects dataset from SAARC countries from 1995 to 2018. This study applies a fixed-effect test and panel vector error correction model (PVECM) test for data analysis. The overall results show that all three renewable energy sources have positively significant impacts on economic development among SAARC countries' economies. Moreover, the hydropower renewable energy source has more effects and influences on economic growth as relatively compared with the rest of the two individual sources of renewable energy.

3.
ISME J ; 14(5): 1223-1232, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32042101

RESUMEN

The trace amounts (0.53 ppmv) of atmospheric hydrogen gas (H2) can be utilized by microorganisms to persist during dormancy. This process is catalyzed by certain Actinobacteria, Acidobacteria, and Chloroflexi, and is estimated to convert 75 × 1012 g H2 annually, which is half of the total atmospheric H2. This rapid atmospheric H2 turnover is hypothesized to be catalyzed by high-affinity [NiFe] hydrogenases. However, apparent high-affinity H2 oxidation has only been shown in whole cells, rather than for the purified enzyme. Here, we show that the membrane-associated hydrogenase from the thermoacidophilic methanotroph Methylacidiphilum fumariolicum SolV possesses a high apparent affinity (Km(app) = 140 nM) for H2 and that methanotrophs can oxidize subatmospheric H2. Our findings add to the evidence that the group 1h [NiFe] hydrogenase is accountable for atmospheric H2 oxidation and that it therefore could be a strong controlling factor in the global H2 cycle. We show that the isolated enzyme possesses a lower affinity (Km = 300 nM) for H2 than the membrane-associated enzyme. Hence, the membrane association seems essential for a high affinity for H2. The enzyme is extremely thermostable and remains folded up to 95 °C. Strain SolV is the only known organism in which the group 1h [NiFe] hydrogenase is responsible for rapid growth on H2 as sole energy source as well as oxidation of subatmospheric H2. The ability to conserve energy from H2 could increase fitness of verrucomicrobial methanotrophs in geothermal ecosystems with varying CH4 fluxes. We propose that H2 oxidation can enhance growth of methanotrophs in aerated methane-driven ecosystems. Group 1h [NiFe] hydrogenases could therefore contribute to mitigation of global warming, since CH4 is an important and extremely potent greenhouse gas.


Asunto(s)
Verrucomicrobia/fisiología , Ecosistema , Hidrógeno , Hidrogenasas/metabolismo , Metano , Oxidación-Reducción , Verrucomicrobia/metabolismo
4.
Int Arch Occup Environ Health ; 93(6): 669-682, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32034472

RESUMEN

OBJECTIVE: Thirty-four geothermal power plants for the production of electricity are currently active in the geothermal areas in Tuscany. The present study aimed to investigate the association between short-term exposure to hydrogen sulfide (H2S) and acute health outcomes. METHODS: This study used individual data on non-accidental, cardiovascular and respiratory mortality, urgent hospital admissions (HA) and emergency department (ED) visits for cardiorespiratory diseases occurring from 2000 to 2017. All cases were georeferenced and matched to daily H2S data, derived from 18 monitoring sites. A case-crossover design following the matched pair interval approach was applied and conditional logistic regression models were fitted to estimate odds ratios and their 90% confidence intervals, adjusting for a set of time-dependent variables, such as influenza epidemics, holidays and temperature. RESULTS: A total of 8054 deaths, 30,527 HA and 15,263 ED visits occurred. Mortality for non-accidental (OR = 1.11, 90% CI 1.02-1.22) and cardiovascular causes (OR = 1.22, 90% CI 1.03-1.44) were associated with an increase of 10 µg/m3 of H2S daily levels only among men. Hospital admissions for respiratory diseases were positively associated with H2S exposure: OR = 1.11 (90% CI 1.00-1.22) among women. No associations were observed in ED visits analyses. CONCLUSIONS: In this case-crossover study in the Tuscan geothermal areas, short-term exposure to H2S was weakly associated with some mortality and morbidity outcomes. Our findings did not show a clear pattern as the results were not homogeneous between mortality and morbidity data or between men and women.


Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Enfermedades Cardiovasculares/epidemiología , Exposición a Riesgos Ambientales/efectos adversos , Energía Geotérmica , Sulfuro de Hidrógeno/efectos adversos , Centrales Eléctricas , Enfermedades Respiratorias/epidemiología , Anciano , Servicio de Urgencia en Hospital , Femenino , Hospitalización , Manantiales de Aguas Termales , Humanos , Italia/epidemiología , Masculino
5.
Sci Total Environ ; 706: 135998, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31862594

RESUMEN

Since the 1990s, in areas with natural geothermal manifestations studies on the association between exposure to pollutants and health effect have become increasingly relevant. These emissions consist of water vapor mixed with carbon dioxide, hydrogen sulfide (H2S), methane and, to a lesser extent, rare gases and trace elements in volatile forms. Considering the indications of the World Health Organization and the growth in the use of geothermal energy for energy production, this review aims to report studies exploring the health status of the populations living in areas where geothermal energy is used to produce heat and electricity. Studies on the health effects of the general population exposed to emissions from both natural geothermal events and plants using geothermal energy at domestic or commercial level have been considered between 1999 and 2019. Studies were classified into those based on health indicators and those based on proxy-individual level exposure metrics. Both statistically significant results (p<0.05) and interesting signals were commented. The 19 studies selected (New Zealand, Iceland and Italy) provide heterogeneous results, with an increased risk for several tumor sites. Exposure to H2S low concentrations is positively associated with an increment of respiratory symptoms, anti-asthma drugs use, mortality for respiratory diseases and lung cancer. Exposure to H2S high levels is inversely related to cancer mortality but associated with an increase in hospitalization for respiratory diseases, central nervous system disorders and cardiovascular diseases. The results indicate that the health of populations residing in areas rich in geothermal emissions presents some critical elements to be explored. The two major limitations of the studies are the ecological design and the inadequate exposure assessment. The authors suggested the prosecution and the systematization of health surveillance and human biomonitoring activities associated with permanent control of atmospheric emissions from both industrial and natural plants.


Asunto(s)
Electricidad , Calor , Humanos , Islandia , Italia , Nueva Zelanda
6.
Sci Total Environ ; 659: 973-982, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31096427

RESUMEN

BACKGROUND: Geothermal power plants for the production of electricity are currently active in Mt. Amiata, Italy. The present study aimed to investigate the association between chronic low-level exposure to H2S and health outcomes, using a residential cohort study design. METHODS: Spatial variability of exposure to chronic levels of H2S was evaluated using dispersion modelling. Cohorts included people residing in six municipalities of the geothermal district from 01/01/1998 to 31/12/2016. Residence addresses were georeferenced and each subject was matched with H2S exposure metrics and socio-economic status available at census tract level. Mortality and hospital discharge data for neoplasms and diseases of the respiratory, central nervous and cardiovascular systems were taken from administrative health databases. Cox proportional hazard models were used to test the association between H2S exposure and outcomes, with age as the temporal axis and adjusting for gender, socio-economic status and calendar period. RESULTS: The residential cohort was composed of 33,804 subjects for a total of 391,002 person-years. Analyses reported risk increases associated with high exposure to H2S for respiratory diseases (HR = 1.12 95%CI: 1.00-1.25 for mortality data; HR = 1.02 95%CI: 0.98-1.06 for morbidity data), COPD and disorders of the peripheral nervous system. Neoplasms were negatively associated with increased H2S exposure. CONCLUSIONS: The most consistent findings were reported for respiratory diseases. Associations with increased H2S exposure were coherent in both mortality and hospitalization analyses, for both genders, with evidence of exposure-related trends. No positive associations were found for cancer or cardiovascular diseases.


Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Exposición a Riesgos Ambientales/análisis , Sulfuro de Hidrógeno/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/inducido químicamente , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/mortalidad , Enfermedades del Sistema Nervioso Central/inducido químicamente , Enfermedades del Sistema Nervioso Central/epidemiología , Enfermedades del Sistema Nervioso Central/mortalidad , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Italia/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias/inducido químicamente , Neoplasias/epidemiología , Neoplasias/mortalidad , Centrales Eléctricas , Trastornos Respiratorios/inducido químicamente , Trastornos Respiratorios/epidemiología , Trastornos Respiratorios/mortalidad , Adulto Joven
7.
Artículo en Inglés | MEDLINE | ID: mdl-25763368

RESUMEN

Recently, technologies have been developed that offer the possibility of using algal biomass as feedstocks to energy producing systems - in addition to oil-derived fuels (Bird et al., 2011, 2012). Growing native mixed microalgal consortia for biomass in association with geothermal resources has the potential to mitigate negative impacts of seasonally low temperatures on biomass production systems as well as mitigate some of the challenges associated with growing unialgal strains. We assessed community composition, growth rates, biomass, and neutral lipid production of microalgal consortia obtained from geothermal hot springs in the Great Basin/Nevada area that were cultured under different thermal and light conditions. Biomass production rates ranged from 39.0 to 344.1 mg C L(-1) day(-1). The neutral lipid production in these consortia with and without shifts to lower temperatures and additions of bicarbonate (both environmental parameters that have been shown to enhance neutral lipid production) ranged from 0 to 38.74 mg free fatty acids (FFA) and triacylglycerols (TAG) L(-1 )day(-1); the upper value was approximately 6% of the biomass produced. The higher lipid values were most likely due to the presence of Achnanthidium sp. Palmitic and stearic acids were the dominant free fatty acids. The S/U ratio (the saturated to unsaturated FA ratio) decreased for cultures shifted from their original temperature to 15°C. Biomass production was within the upper limits of those reported for individual strains, and production of neutral lipids was increased with secondary treatment. All results demonstrate a potential of culturing and manipulating resultant microalgal consortia for biomass-based energy production and perhaps even for biofuels.

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