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Результаты 2601-2610 из 4,043
A study on possible use of Urtica dioica (common nettle) plant as polonium 210Po and lead 210Pb contamination biomonitor in the area of phosphogypsum stockpile Полный текст
2016
Olszewski, Grzegorz | Boryło, Alicja | Skwarzec, Bogdan
The aim of this study was to test a possible use of Urtica dioica (common nettle) plant as a biomonitor of polonium ²¹⁰Po and lead ²¹⁰Pb contamination near phosphogypsum stacks by determining concentrations of these radionuclides in samples collected from the area of phosphogypsum stockpile in Wiślinka (northern Poland). The ²¹⁰Po and ²¹⁰Pb contents in roots depended on their concentrations in soils. Bioconcentration factor values from soil to root of the plant did not depend on ²¹⁰Po and ²¹⁰Pb contents in soils that leads to the conclusion that different polonium and lead species have different affinities to U. dioica plants. The main sources of both analyzed radionuclides in green parts of plants are wet and dry air deposition and transportation from soil. The values of ²¹⁰Po/²¹⁰Pb activity ratio indicate natural origin of these radioisotopes in analyzed plants. ²¹⁰Po and ²¹⁰Pb concentration in U. dioica roots is negatively weakly correlated with distance from phosphogypsum stockpile.
Показать больше [+] Меньше [-]Natural and human impacts on ecosystem services in Guanzhong - Tianshui economic region of China Полный текст
2016
Li, Jing | Zhou, Z. X.
Due to the accelerated growth of society, the gaps between the capacity of ecosystems to provide services and human needs are steadily widening. Natural, semi-natural, or managed ecosystems had been able to provide ecosystem services to meet the needs of social development. Four agricultural ecosystem services (net primary production (NPP), carbon sequestration and oxygen production (CSOP), water interception, soil conservation and agriculture production) were quantified in Guanzhong-Tianshui economic region. Estimates of ecosystem services were obtained from the analysis of satellite imagery and the use of well-known models. Based on the ecological services in Guanzhong-Tianshui economic region, this study mainly analysed the driving mechanism of the changes from the two aspects of natural drivers and human drivers. Natural drivers (climate, soil, elevation, land cover) had incentive to the ecological services. Human activity was quantified by an integrated human activity index (HAI) based on population density, farmland ratio, and the influence of road networks and residential areas. We found relationships between ecosystem services, human activities and many natural factors, however these varied according to the service studied. Human activities were mostly negatively related to each ecosystem services, while population and residential land ware positively related to agricultural production. Land use change had made a contribution to ecosystem services. Based on the selected ecosystem services and HAI, we provided sustainable ecosystem management suggestions.
Показать больше [+] Меньше [-]First report on fish cysteine as a biomarker of contamination in the River Chenab, Pakistan Полный текст
2016
Hussain, Bilal | Sultana, Tayyaba | Sultana, Salma | Mahboob, Shahid | Fārūq, Muḥammad | Al-Ghanim, Khalid | Nadeem, Shahid
The eastern and southern parts of the Faisalabad city produce considerable quantities of industrial and municipal pollutants, much of which is drained into the River Chenab, reducing the productivity of fauna and flora in the river. This study was aimed to determine whether cysteine is useful as a biomarker of exposure to polluted fresh water. The amino acid profile of fish muscle was analyzed by paper chromatography in Cirrhinus mrigala and Labeo rohita from the River Chenab to determine habitat related variations due to the pollution from industrial and domestic sources. C. mrigala showed higher level of metal contamination in muscle tissues for Sn, Cr, Pb, Zn, Mn, Cu, and Cd when compared to L. rohita. Both fish species collected from polluted areas of the river Chenab showed significantly (P < 0.01) higher levels of metals in comparison to upstream and farmed fish. Farmed C. mrigala showed cysteine concentrations in the muscle tissue as 22 ± 1 mg/g dry weight, but concentrations increased to 45 ± 2 mg/g dry weight for fish from a mildly polluted section of the river, and further increased to 83 ± 2 mg/g dry weight in more heavily polluted sections. Cysteine concentration in farmed L. rohita was detected as 28 ± 2 and 25 ± 4 mg/g dry weight, respectively for farmed fish and fish from a mildly polluted section of the river, and then increased to 94 ± 3 mg/g dry weight for fish from highly polluted water. C. mrigala from a mildly polluted area of the river also had higher levels of cysteine in the muscle, along with increases in aspartic acid, glutamic acid, and alanine. Elevated concentrations of cysteine seem to be associated with a threat to these fish species in polluted sections of the river, and thus may be used as a biomarker.
Показать больше [+] Меньше [-]Biomarkers in the freshwater bivalve Corbicula fluminea confined downstream a domestic landfill leachate discharge Полный текст
2016
de Oliveira, Luciana Fernandes | Santos, Caroline | dos Reis Martinez, Claudia Bueno
Landfills represent a severe environmental problem mainly due to the generation of leachates, and this study aimed to evaluate sublethal effects of a domestic landfill leachate in the freshwater bivalve Corbicula fluminea. Clams were submitted to in situ tests along a stream, at three sites, representing increasing distances from the leachate discharge (Pq1, Pq2, and Pq3), for 1, 5, and 15 days. The following biomarkers were analyzed in the gills and digestive glands: 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities, multixenobiotic resistance mechanism (MXR), total antioxidant capacity (TAC), reactive oxygen species (ROS), and lipid peroxidation (LPO). Metallothionein (MT) content was determined in the gills and DNA damage in hemocytes. The mortality rate of animals during in situ tests was reduced as the distance from the leachate discharge source increased. On the other hand, biomarker results showed sublethal effects on C. fluminea confined at all sites of PqS. GST, TAC, ROS, and DNA damage were the most significant biomarkers for this species and should be considered for future monitoring and assessment of freshwater environments located in landfill areas.
Показать больше [+] Меньше [-]Toxicity of OTC to Ipomoea aquatica Forsk. and to microorganisms in a long-term sewage-irrigated farmland soil Полный текст
2016
Ma, Tingting | Chen, Li’ke | Wu, Longhua | Christie, Peter | Luo, Yongming
Water spinach (Ipomoea aquatic Forsk.) was selected to investigate the effects of oxytetracycline (OTC) on the toxicity of soil contaminated by long-term sewage irrigation. After acute toxicity test in petri dish at nine different OTC-spiked levels for 48 h, the germination rate was found to be generally inhibited in all treatments treated with OTC but the root elongation and activities of several antioxidant enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were either forward or backward stimulated to varying extent. During a 60-day sub-chronic toxicity test by means of a pot experiment, activities of SOD, POD and CAT in both the leaf and root tissue at 25 mg OTC per kg soil (dry weight) and in root tissue at 1 mg OTC per kg soil (dry weight) were significantly different than those in other treatments, which also indicated the higher sensitivity of the root. The foliar photosynthetic rate, stomatal conductance and transpiration rate were all gradually inhibited in spite of elevated water use efficiency under the pressure of the different OTC concentrations, which were highly significant different at 10 mg OTC per kg soil (dry weight). Indices of soil microbial diversity at 4 mg OTC kg⁻¹ soil were significantly different from those of the control, indicating the potential adverse effects of OTC to soil microorganisms. The results suggest that the introduction of OTC could damage both plants and soil microorganisms, and during sub-chronic incubation, the sensitivity of different indices generally followed the order of root tissue antioxidant enzyme activities, soil microbial diversity indices, leaf photosynthesis-related index and leaf tissue enzyme antioxidant activities. In addition, the application of livestock and poultry manure containing pollutants like OTC in farmland soil, especially if the soil has been contaminated before, should be taken more seriously in the context of the current pursuit of increased agricultural production.
Показать больше [+] Меньше [-]Cadmium availability and uptake by radish (Raphanus sativus) grown in soils applied with wheat straw or composted pig manure Полный текст
2016
Shan, Hong | Su, Shiming | Liu, Rongle | Li, Shutian
Soil cadmium (Cd) availability and uptake by cherry-red radish (Raphanus sativus) grown in Cd-contaminated soils after addition with wheat straw or composted pig manure were studied. The results indicated that wheat straw application promoted radish growth until the second harvest, while pig manure application improved radish biomass in Acid Ferralsols regardless of harvesting seasons. Application with pig manure might be more effective in lowering the Cd uptake by radish than wheat straw. Especially when pig manure of 11.9 g TOC kg⁻¹ amended into Acid Ferralsols, Cd contents in leaves and roots of radish decreased by 89.2 and 95.7 % at the second harvest, respectively. The changes in Cd fractions distribution in soils after application were contributed to the decline of Cd availability. Furthermore, significantly negative linear correlation (P < 0.05) between the ratio of humic acid (HA) and fulvic acid (FA) in soils and exchangeable Cd was also observed. However, the significantly negative relationship (P < 0.01) between soil pH and exchangeable Cd was merely found in pig manure-treated Acid Ferralsols. The increases in HA/FA ratio or pH values in soils after adding organic materials were also responsible for the decrease of Cd availability in soils and uptake by radish. Thus, it is recommended to stabilize soil Cd and reducing plant uptake by application with composted manure without or slightly contaminated with metals.
Показать больше [+] Меньше [-]Effect of landfill cover layer modification on methane oxidation Полный текст
2016
Hu, Lifang | Long, Yuyang
Levels of methane (CH₄) oxidation in materials used for landfill cover attained in the laboratory are not often replicated in the field due to effects from the surrounding environment. This study investigates the three dominant factors affecting CH₄ oxidation in the cover layer, namely, the thickness of cover layer, the methanotroph spraying manner, and the osmotic coefficient of the cover material. Results show that improved CH₄ emission performance of the cover layer can be realized if methanotroph are introduced, meaning that a thinner cover layer is required. The highest CH₄ emission reduction can be realized by spraying methanotroph into the top, middle, and bottom layers of a 30-cm thick cover layer with an osmotic coefficient of 7.76 × 10⁻⁵ cm s⁻¹. Comparing results on cover layer thickness, methane monooxygenase (MMO) activity was much lower with increasing thickness meaning that the thicker cover could reduce O₂ availability, thus inhibiting MMO activity. This suggests that MMO may be responsible for differences in CH₄ emission reduction and/or oxidation making the osmotic coefficient an important factor for cover layer material.
Показать больше [+] Меньше [-]Occurrence of pharmaceuticals in WWTP effluents and their impact in a karstic rural catchment of Eastern France Полный текст
2016
Chiffre, Axelle | Degiorgi, François | Buleté, Audrey | Spinner, Loïc | Badot, Pierre-Marie
The occurrence of pharmaceuticals in freshwater ecosystems provokes increasing concern due to their potential risk to non-target organisms and to human health. Pharmaceuticals are used in both human and veterinary medicine and are essentially released into the environment via wastewater treatment plants (WWTPs) and from livestock. In this study, 31 pharmaceuticals were analyzed in effluent and surface water upstream and downstream of two WWTPs in the Loue–Doubs rural karstic catchment in Eastern France. Diclofenac (965 and 2476 ng L⁻¹), sulfamethoxazole (655 and 1380 ng L⁻¹) and carbamazepine (566 and 1007 ng L⁻¹) displayed the highest levels in the effluents of both WWTPs. Diclofenac levels were also high in surface water samples 300 and 166 ng L⁻¹ in the River Doubs and the River Loue, respectively, followed by paracetamol (273 and 158 ng L⁻¹) and sulfamethoxazole (126 and 73 ng L⁻¹). In both rivers, the most critical compounds were found to be the antibiotic sulfamethoxazole (risk quotient (RQ) from 23.7 to 51.1) and ofloxacine (RQ from 1.1 to 18.9), which reached levels inducing toxic effects in aquatic organisms. This study showed that WWTP effluents are the major sources of the pharmaceuticals, but raw discharges from human residences, pastures and livestock manure represent significant sources of contamination of surface water and groundwater. The aim of this study was to assist scientists and authorities in understanding occurrence and sources of pharmaceuticals in order to improve water quality management in chalk streams.
Показать больше [+] Меньше [-]Cold homes are associated with poor biomarkers and less blood pressure check-up: English Longitudinal Study of Ageing, 2012–2013 Полный текст
2016
Shiue, Ivy
It has been known that outdoor temperature influences seasonal fluctuation of blood pressure and cholesterol levels, but the role of indoor temperature has been less studied. Therefore, the aim of the present study was to examine the associations between indoor temperature and biomarkers in a countrywide and population-based setting. Data was retrieved from the English Longitudinal Study of Ageing, 2012–2013. Information on demographics, room temperature and a series of biomarkers measured in the blood and lung was obtained at household interviews. t test, chi-square test and a generalized linear model were performed cross-sectionally. Of 7997 older adults with the valid indoor temperature measurements, there were 1301 (16.3 %) people who resided in cold homes (<18 °C). Age was inversely associated with people who resided in cold homes or who tended not to have blood pressure check-up. Those who resided in cold homes had higher blood pressure readings, worse handgrip, lower vitamin D levels, higher cholesterol levels, higher insulin-like growth factor levels, higher haemoglobin levels, lower level of white blood cell count and worse lung conditions. One in six older adults aged 50 and above in England resided in cold homes and had poor biomarker values. For the future research direction, studies with a longitudinal approach to systematically monitor indoor temperature, biomarkers and health and wellbeing would be suggested. From the practice and policy perspectives, increasing health knowledge on the adverse effect of low indoor temperature on risks of cardiac and respiratory conditions, affording to the heating and re-designing of residential buildings to keep warm by using efficient energy, should be kept as priority.
Показать больше [+] Меньше [-]Cadmium accumulation and growth response to cadmium stress of eighteen plant species Полный текст
2016
Shi, Gangrong | Xia, Shenglan | Liu, Caifeng | Zhang, Zheng
This study investigated the cadmium (Cd) accumulation and growth response to Cd stress of 18 plant species. After growth for 30 days in the sand containing 0, 2, or 10 mg Cd kg⁻¹, seedlings were evaluated for growth parameters, specific root length, and Cd accumulation. The 18 species differ greatly in Cd accumulation and resistance to Cd stress, depending on Cd concentrations in the sand. Under high Cd condition (10 mg kg⁻¹), the 18 species were classified into two groups: (1) Indian mustard and rapeseed having high Cd tolerance and increased accumulation capacity in shoots could be considered as Cd accumulators, and (2) the remaining 16 non-accumulators constitute a species continuum from the indicators to excluders. Shoot Cd concentration showed exponential decay relationships with biomass production, absolute growth rate, and growth ratio, indicating that biomass production negatively relates to the shoot Cd concentration in non-accumulators via dilution or concentration effect. Species with high biomass generally accumulate low Cd in the shoots and display high Cd-tolerant capacity. Indian mustard and rapeseed are promising species for long-term phytoextraction of Cd-contaminated farmlands for bioenergy production.
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